﻿A critical review on cytogenetics of Cucurbitaceae with updates on Indian taxa

Biplab Kumar Bhowmick; Sumita Jha

doi:10.3897/compcytogen.v16.i2.79033

. 2022 Apr 26;16(2):93–125. doi: 10.3897/compcytogen.v16.i2.79033

A critical review on cytogenetics of Cucurbitaceae with updates on Indian taxa

Biplab Kumar Bhowmick ¹, Sumita Jha ^2,^✉

PMCID: PMC9849056 PMID: 36761811

Abstract

The cytogenetic relationships in the species of Cucurbitaceae are becoming immensely important to answer questions pertaining to genome evolution. Here, a simplified and updated data resource on cytogenetics of Cucurbitaceae is presented on the basis of foundational parameters (basic, zygotic and gametic chromosome numbers, ploidy, genome size, karyotype) and molecular cytogenetics. We have revised and collated our own findings on seven agriculturally important Indian cucurbit species in a comparative account with the globally published reports. Chromosome count (of around 19% species) shows nearly three-fold differences while genome size (of nearly 5% species) shows 5.84-fold differences across the species. There is no significant correlation between chromosome numbers and nuclear genome sizes. The possible trend of evolution is discussed here based on molecular cytogenetics data, especially the types and distribution of nucleolus organizer regions (NORs). The review supersedes the scopes of general chromosome databases and invites scopes for continuous updates. The offline resource serves as an exclusive toolkit for research and breeding communities across the globe and also opens scope for future establishment of web-database on Cucurbitaceae cytogenetics.

Keywords: chromosome, genome size, karyotype, NORs, ploidy

Introduction

The family Cucurbitaceae contains an extensive range of diversity consisting of about 1000 species spread over 96 genera (Renner and Schaefer 2017). The diversity of plant families is associated with variation in genome sizes and chromosome numbers as a result of enormous adaptive radiation (Soltis et al. 2004; Lysák and Schubert 2013). The viewpoint of evolution has been changed with the understanding of whole genome duplication (WGD) (Soltis et al. 2014) followed by core-eudicot hexaploidy (Wang et al. 2018). A cytogenetic database is essential to gain insights into evolution by supplementing phylogeny trees with chromosome number information (Mota et al. 2016) to upgrade knowledge on plant systematics (Soltis et al. 2014; Viruel et al. 2021). Cucurbitaceae, being the fourth most important and one of the earliest consumed vegetables yielding family, has coped with extreme climates, extensive human intervention and a huge domestication syndrome (Chomicki et al. 2020). Considerable advances have been made in molecular phylogeny (Renner and Schaefer 2016; Bellot et al. 2020; Chomicki et al. 2020; Guo et al. 2020) and genomics (CuGenDB, http://cucurbitgenomics.org) (Zheng et al. 2019). We had previously discussed about the gaps in cytogenetic studies (Bhowmick and Jha 2015b) which has been surmounted with the advent of molecular cytogenetics.

Currently, we have collated the cytogenetic reports of Cucurbitaceae globally and integrated our own findings for a collective interpretation. The review attempts to address i) the trend of chromosome evolution in specific tribes and species based on available information, ii) correlation between chromosome numbers and ploidy or genome size in the studied taxa and iii) the requirement of an exclusive cytogenetic catalogue for genome researchers, taxonomists and breeders working on Cucurbitaceae.

Methodological approaches

Data compilation

The data have been collated as per Schaefer and Renner (2011) after consultation of books, Chromosome atlases, research articles and public resources like Chromosome Counts Database (CCDB; http://ccdb.tau.ac.il/) (Rice et al. 2015), The Index to Plant Chromosome Numbers (IPCN, http://legacy.tropicos.org/Project/IPCN) (Goldblatt and Lowry 2011) and The Plant DNA C-values database (Pellicer and Leitch 2020) (https://cvalues.science.kew.org/).

Chromosome analysis in the Cucurbit species ocurring in India

Presently an enzymatic maceration and air drying (EMA) method followed by flurochrome banding has been employed as per our previous protocols (Bhowmick et al. 2012, 2016; Bhowmick and Jha 2015a, 2019, 2021) to represent fresh karyotypes of seven agriculturally important cucurbit species (Table 1) belonging to Benincaseae and Sicyoeae. Fresh and healthy roots were used from different sources (like germinating seeds, seedlings and underground root stocks). Roots were pretreated with 0.002 M hydroxyquinoline and fixed in 1:3 aceto-methanol solution. The standardization of EMA- fluorescence banding was conducted for the different species. In brief, fixed roots were digested in enzyme mixture [1% Cellulase (Onozuka RS), 0.75% Macerozyme (R-10), 0.15% Pectolyase (Y-23), 1 mM EDTA] for 40–45 min at 37 °C, macerated on slides, air-dried, stained with 2% Giemsa solution (Merck, Germany) and plates selected for karyotyping. After de-staining, slides were kept in McIlvaine buffer, stained with 0.1 µg mL^-1 DAPI for 15–20 min in darkness. For CMA staining, slides were incubated in 0.1 mg mL^-1 CMA for 15–25 min in darkness. For meiotic chromosomes, fixed anthers were digested in enzyme mixture for 5–8 min, macerated on slides and DAPI staining protocol was followed with minor modifications. All slides were mounted in non-fluorescent glycerol and chromosome plates were observed under a Zeiss Axioscop 2 fluorescence microscope (using UV and BV filter cassettes for DAPI and CMA stains, respectively). Images were captured using the attached ProgRes MFscan Jenoptik D07739 camera and ProgRes CapturePro 2.8.8 software.

Table 1.

Chromosome numbers and nature of fluorescent bands in some cucurbit species occurring in India.

Tribes	Species (common name, status of cultivation/ wild)	Collection site, Latitude/ Longitude	Fruit image	2n	CMA bands		DAPI bands (Non-nucleolar)
Tribes	Species (common name, status of cultivation/ wild)	Collection site, Latitude/ Longitude	Fruit image	2n	Nucleolar	Non-nucleolar	DAPI bands (Non-nucleolar)
*Sicyoeae*	Luffaacutangula Linnaeus, 1753 (ridged gourd, cultivated)	Bhubaneswar, Odisha, 20.2960°N, 85.8245°E		26	11^th , 12^th, 13^th	12^th (centromeric)	1^st to 13^th (distal)
	Luffacylindricaaegyptiaca Miller, 1768 (sponge gourd, cultivated)	Imphal, Manipur, 24.6637°N, 93.906°E		26	12^th , 13^th	1^st , 2^nd (distal)	0
	Luffaechinata Roxburgh, 1814 (wild)	Pantnagar, Uttarakhand, 30.0667°N, 79.019°E		26	11^th , 12^th , 13^th	0	1^st to 13^th (distal)
	Trichosanthescucumerina Linnaeus, 1753 (wild)	NBPGR, Thrissur, Kerala, 10.5276°N, 76.2144°E		22	10^th , 11^th	0	1^st to 11^th (distal)
	Trichosanthescucumerinassp.cucumerina Anguina (snake gourd, cultivated)	Bengaluru, 12.9716°N, 77.5946°E		22	10^th , 11^th	2^nd (distal)	0
	Trichosanthesdioica Roxburgh, 1832 (pointed gourd, cultivated)	Bhagalpur, Bihar, 25.2414°N, 86.9924°E		22 (female)	0	7^th , 8^th , 10^th (distal)	1^st to 11^th
		Bhagalpur, Bihar, 25.2414°N, 86.9924°E	22 (male)	0	0	1^st to 11^th
*Benincaseae*	Benincasahispida Thunberg, 1784 (ash gourd, cultivated)	Imphal, Manipur 24.6637°N, 93.906°E		24	12^th	9^th (distal)	0
	Cocciniagrandis Linnaeus, 1767 (ivy gourd, restricted cultivation)	Nagpur, Maharashtra, 21.1458°N, 79.0881°E		24 (female)	8^th, 12^th *	1^st to 5^th, 8^th to 12^th (centromeric)	0
		Nagpur, Maharashtra, 21.1458°N, 79.0881°E	24 (male)	8^th, 12^th *	1^st to 5^th, 8^th, 10^th to 12^th (centromeric)	0

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Statistical analyses

Statistical analysis involving foundational cytogenetic parameters have been demonstrated to imply significant knowledge on chromosomal evolution within a group (Winterfeld et al. 2020). Considering the lack of hypotheses, we have tested for correlation between the dependent variables (2C genome size, MCL and HCL) and predictor variables [chromosome number (2n) and ploidy level (pl)] and also calculated linear models for regression analysis using IBM SPSS (v23, free).

The modern cytogenetic catalogue of cucurbitaceae

Along with the global review, fresh EMA based somatic plates and idiograms (Figs 1–3) of Indian species are presented here. We retain the previous designation of 10 tribes as ‘understudied’ (Bhowmick and Jha 2015b), excluding Indofevilleeae, having no cytological reports.

Figure 1. — Somatic metaphase chromosomes and idiograms of *Luffa* species (2n = 26) stained with Giemsa (**A, D, G**), DAPI (**B, E, H**) and CMA3 (**C, F, I**) **A–C***L.acutangula***D–F***L.aegyptiacacylindrica***G–I***L.echinata*. Arrows indicate satellited chromosomes in Giemsa plates and CMA^+ve signals in **C, F, I**. Corresponding somatic idiograms (haploid set) of: JL.acutangulaKL.aegyptiacaLL.echinata, showing DAPI^+ve (blue) and CMA^+ve (golden yellow) bands. Scale Bars: 5 µm

Figure 3. — Somatic metaphase chromosomes and idiograms of two *Benincaseae* species (2n = 24) stained with Giemsa (**A, D, G**), DAPI (**B, E, H**) and CMA3 (**C, F, I**) **A–C***Benincasahispida***D–F***Cocciniagrandis* (female plant) **G–I***Cocciniagrandis* (male plant). Arrows indicate satellited chromosomes in Giemsa plates and distal CMA^+ve signals in **C, F, I**. Note the longest Y chromosome without any CMA band in **G–I** and centromeric CMA^+ve signals in **F, I**. Corresponding somatic idiograms (haploid set) of: JBenincasahispidaKCocciniagrandis (female plant) LCocciniagrandis (male plant) with CMA^+ve (golden yellow) bands. Note the X chromosome remaining indistinguishable in L. Scale Bars: 5 µm

Chromosome numbers

Currently, chromosome counts are available for 188 species (~19%) belonging to about 44 genera (~46%) of the 15 tribes, including the less attended ‘understudied tribes’. Within the ‘understudied tribes’, chromosome counts are available for only 42 species (out of almost 310) belonging to 17 genera (out of nearly 44). The basal number ranges from x/n = 5 (Thladiantha Bunge, 1833) to x/n = 15 (Zanonia Linnaeus, 1753) in these tribes (Table 2). Polyploidy has been abundantly reported in Gomphogyneae. Momordiceae have almost 60 species (Schaefer and Renner 2011) of which reports are known in nearly 11 species. The dibasic condition is noticed in Momordica Linnaeus, 1753 (x = 11 and 14) (Table 3) while polyploidy is detected in M.charantia Linnaeus, 1753 and M.dioica Willdenow, 1805 (2n = 56). M.cymbalaria Hooker, 1871, has the lowest count (2n = 18). In Bryonieae the X-Y sex determination system has been analysed in Bryonia Linnaeus, 1753 as the model along with Ecballium Richard, 1824 (Bhowmick and Jha 2015a). Chromosome counts are reported so far in 10 species of Bryonia (x = 10) and its sister genus Ecballium (x = 12 or x = 9, Table 4). Polyploidy is frequent in Bryonia. Sicyoeae is largest in terms of species (~264–266 species) (Schaefer and Renner 2011) of which cytological reports are known in around 14% species belonging to 9 genera (Table 5). Sicyoeae species range from x = 8 to x = 14 (Table 5). Trichosanthes Linnaeus, 1753 and Luffa Miller, 1754 have x = 11 and x = 13, respectively (Table 1). The less prevalent numbers include x = 12, x = 8 and x = 9 (Table 5). The possibility of multiple base number is noted in Frantzia Pittier, 1910 (x = 12/14) and Sicyos Linnaeus, 1753 (x = 12/13/14). Natural tetraploids are known in two species of Trichosanthes while the majority are diploids. Benincaseae is the second largest tribe comprising of 204–214 species in 24 genera (Schaefer and Renner 2011). Cytological reports are known in around 35% species (76 species of which 41 belong to Cucumis Linnaeus, 1753) of 12 genera (Tables 6, 7). x = 12 is the prevalent condition in Benincaseae (Tables 1, 6, 7). Dual base numbers are noted in the widely studied Cucumis (x = 7, 12). Coccinia Wight et Arnott, 1834 (x = 12) may also possess dual base numbers (x = 10 in C.trilobata Cogniaux, 1895). Molecular cytogenetics of Cucumissativus Linnaeus, 1753 has demonstrated the evolution of x = 7 from x = 12 in Benincaseae. x = 11 has been confirmed in Citrullus Schrader, 1836 and Lagenaria. The base number of Melothria Linnaeus, 1753, Solena Loureiro, 1790 and Zehneria Endlicher, 1833 can be x = 11 or x = 12 or both (Table 6). Cases of natural polyploidy are noted only in four species of Cucumis (Table 7). Cytogenetic information is available for 17 species in three genera of Cucurbiteae with x = 10 and many polyploids (Table 8). The zygotic chromosome numbers of Luffa, Trichosanthes, Benincasa Savi, 1818 and Coccinia, corroborate the previous reports (Figs 1–3, Table 1).

Table 2.

Cytogenetic reports in the understudied tribes of Cucurbitaceae #.

Tribe and Genera	Species studied	Chromosome no.			Ploidy, Genome size, Chromosome features	References
Tribe and Genera	Species studied	x	2n	n	Ploidy, Genome size, Chromosome features	References
*Gomphogyneae*Gomphogyne Griffith, 1845	G.cissiformis Griffith, 1837		32^a	16^b	Tetraploid^c, autopolyploid^d; 10 secondary constrictions, one pair satellited^e; II, III, IV in meiosis^f	CCDB^b; Kumar and Subramaniam (1987)^a, Singh (1990)^a,d, Roy et al. (1991)^a,c,e,f
Hemsleya F.B. Forbes et Hemsley, 1888	H.amabilis Diels, 1912, H.carnosiflora Wu et Chen, 1985, H.chinensis Forbes et Hemsley, 1888, H.emeiensis Shen et Chang, 1983, H.graciliflora Cogniaux, 1916, H.heterosperma Wallich, 1831, H.macrocarpa Cogniaux, 1916, H.panacis-scandens Wu et Chen, 1985, H.sphaerocarpa Kuang et Lu, 1982	7^a	28^b, 22^c, 24^d, 26^e, 32^f, 40^g, 42^h	14^h	Tetraploidⁱ, aneuploids^j	Samuel et al. (1995)^a-j, Anmin et al. (2011)^{b, h}
Gynostemma Blume, 1825	G.cardiospermum Oliver, 1892	11^a	66^b		Hexaploid^c	IPCN ^a-c
	G.guangxiense Chen et Qin, 1988		22 ^a		Diploid ^b	IPCN ^a,b
	G.laxiflorum Wu et Chen, 1983		22 ^a		Diploid ^b	IPCN ^a,b
	G.longipes Wu et Chen, 1983		22^a, 44^b		Polyploid^c	IPCN ^a-c
	G.microspermum Wu et Chen, 1983		22^a		Diploid ^b	IPCN ^a,b
	G.pedatum Blume, 1825	12^a	24^b		Diploid^c	Roy et al. (1991) ^a,b,c
	G.pentagynum Wang, 1989		22^a		Diploid ^b	IPCN ^a,b
	G.pentaphyllum Thunberg, 1784		22^a, 24^b, 64^c, 66^d		Diploid^e, triploid^f, hexaploid^g; 2C (flow cytometry): 3.62pg^h; 17M+14sm+2stⁱ; CSR: 2.16–4.09 µm^j 5S (8), 45S (10) rDNA and telomeric signals^k	IPCN^a,b,c,e,f; Zhang et al. (2013)^h, Pellerin et al. (2018)^d,g,i,j,k
	G.pentaphyllumvar.dasycarpum Wu, 1983		22^a, 33^b, 44^c		Polyploid^d	IPCN ^a-d
	G.pentaphyllumvar.pentaphyllum Thunberg, 1784		22^a, 44^b, 66^c, 88^d		Polyploid^e	IPCN ^a-e
	G.yixingense Wang et Xie, 1981		88^a		Polyploid^b	IPCN ^a,b
*Triceratieae*		8^a			-	Roy et al. (1991) ^a
Fevillea Linnaeus, 1753		8^a			-	Roy et al. (1991) ^a
*Zanonieae*Zanonia Linnaeus, 1753	Z.indica Linnaeus, 1759	15^a	30^b	15^c	Autoploid^d; Metacentric chromosomes^e; CSR: 1.10-1.98 μm^f	Lekhak et al. (2018) ^a-f
*Actinostemmateae*	A.lobatum (Maxim.) Maxim. ex Franch. & Sav.		16^a		-	IPCN ^a
Actinostemma Griffith, 1841	A.tenerum Griffith, 1837		16^a		Diploid^b; 7M +1sm^c; CSR: 2.88–4.02 µm^d; 45S (1) rDNA and 45S+5S (1) rDNA adjacent signal^e; telomeric repeat signals^f	Pellerin et al. (2018) ^a-f
*Thladiantheae*	T.calcarata Clarke, 1876, T.cordifolia Blume, 1826 T.davidii Franchet, 1886, T.dentata Cogniaux, 1916, T.lijiangensis Lu et Zhang, 1981, T.nudiflora Hemsley, 1887, T.pustulata Léveillé, 1916
Thladiantha Bunge, 1833		3^a, 5^b, 9^c	18^d	5^e, 9^f	Diploid^g	Darlington and Janaki Ammal (1945)^c; Roy et al. (1991)^a,b,d,e,g, IPCN^d,f
Thladiantha Bunge, 1833	T.dubia Bunge, 1833	3^a, 5^b, 9^c	18^a, 22^b	5^e, 9^f	Diploid^c; 7M+1sm+1st^d; CSR: 2.60–4.10 µm^e; 45S (4) and co-localized 45S+5S (1) rDNA signals^f; telomeric repeat signals^g	Samuel et al. (1995)^b, Pellerin et al. (2018)^a,c,d,e,f,g
Baijiania Lu et Li, 1993	B.yunnanensis Lu et Zhang, 1984		32^a		-	IPCN ^a
*Siraitieae*Siraitia Merrill, 1934	S.grosvenorii Swingle, 1941		28^a		45S (6) and 5S (2) rDNA signals^b	IPCN^a, Li et al. (2007)^b
*Joliffieae*Telfairia Hooker, 1827	T.occidentalis Hooker, 1871		22^a, 33^b, 44^c		Diploid^d, aneuploid^e, triploid^f, Tetraploid^g; 1 B^h	Uguru and Onovo (2011) ^a-h
*Joliffieae*Telfairia Hooker, 1827	T.pedata Sims, 1826		22^a		-	Bhowmick and Jha (2015)^a
*Schizopeponeae*Herpetospermum Hooker, 1867	H.pedunculosum Seringe, 1828			11^a	45S (14), 5S (2) rDNA signals^b	Xie et al. (2019a) ^a,b
Schizopepon Maximowicz, 1859	S.bryoniifolius Maximowicz, 1859	10^a	20^b		-	Roy et al. (1991)^a, IPCN^b
*Coniandreae*Apodanthera Arnott, 1841	A.undulata Gray, 1853	14^a			-	IPCN ^a
Corallocarpus Bentham et Hooker, 1867	C.epigaeus Rottler, 1803		26^a	13^b	-	Beevy and Kuriachan (1996) ^a,b
Corallocarpus Bentham et Hooker, 1867	C.welwitschii Naudin, 1863		72^a		-	Singh (1990)^a
Ibervillea Greene, 1895		11^a, 12^b			-	Darlington and Janaki Ammal (1945) ^a,b
Kedrostis Medikus, 1791	K. africana Linnaeus, 1753		40^a		2C (feulgen densitometry): 0.8 pg^b; 2C (flow cytometry): 1674 Mbp^c	Bennet et al. (1982)^a,b, Plant C DNA Values Database^c
	K.foetidissima Jacquin, 1788		26^a	13^b		Beevy and Kuriachan (1996) ^a,b
	K.rostrata Rottler, 1803	13^a	26^b	13^c	-	IPCN ^a-c
Seyrigia Keraudren, 1960				13^a	-	IPCN ^a

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# x: base number; 2n: zygotic number; n: gametic number; CSR: chromosome size range; B: B chromosome; II: bivalents, III: trivalent, IV: tetravalent; superscripts correspond to references.

Table 3.

Cytogenetic information in Momordica (Momordiceae)#.

Species	Chromosome no.		Ploidy, Genome size, Chromosome features	References
Species	2n	n	Ploidy, Genome size, Chromosome features	References
M.balsamina Linnaeus, 1753	22^a		Diploid^b; two chromosomes with double constrictions^c; CSR:0.65–1.98µm^d; MCL:1.30µm^e; TCL: 28.61µm^f	Bharathi et al. (2011) ^a-f
M.charantia	22^a	11^b	Diploid^e, 2C (Feulgen densitometry): 4.10pg ^f, 2C (flow cytometry): 1.43pg^g; chromosomes mostly metacentric, few submetacentric and subtelocentric^h; 2 chromosomes with satellitesⁱ; CSR: 1.26-1.81µm^j; 45S (4) and 5S (2) rDNA signals^k	Plant DNA C-Values Database^f; Bharathi et al. (2011)^a,i ; Barow and Meister (2003)^g; Lombello and Pinto-Maglio (2007)^a,b,h; Bharathi et al. (2011); Waminal and Kim (2012)^a,e,h,j,k; Kausar et al. (2015)^a; Kido et al. (2016)^a,i
M.charantiavar.charantia	22^a	11^b	Diploid^c; 2C (flow cytometry): 0.72pg^d; NORs: 4^e; nucleolar and centromeric CMA⁺ bands^f ; CSR: 1.27-3.07µm^g; MCL: 1.97 µm^h; HCL: 21.77µmⁱ	Ghosh et al. (2018)^a-f; Ghosh et al. (2021)^a,c,d,g,h,i
M.charantiavar.muricata Chakravarty, 1982	22^a	11^b	Diploid^c; 2C (flow cytometry): 1.16pg^d; NORs: 6^e; nucleolar and centromeric CMA⁺ bands^f; CSR: 1.64-3.13µm^g; MCL: 2.19µm^h; HCL: 24.19µmⁱ	Ghosh et al. (2018)^a-f; Ghosh et al. (2021)^a,c,d,g,h,i
M.cochinchinensis Loureiro, 1790	28^a	14^b	Diploid^c, 2C (flow cytometry): 2.64pg^d, 6^e chromosomes with secondary constrictions; CSR:1.16–2.03µm^f /1.71-3.17μm^g ; MCL: 2.27µm^h; HCL: 31.86μmⁱ; 45S (8) and 5S (2) rDNA signals^j	IPCN^b; Xie et al. (2019a)^a,j; Bharathi et al. (2011)^a,e,f; Ghosh et al. (2021)^a,c,d,g,h,i
M.cymbalaria	18^a	8^b, 9^c, 11^d	Diploid^e, 2C (flow cytometry): 3.74 pg^f; 2^g–4^h chromosomes with secondary constrictions; CSR: 2.71-4.57μmⁱ; MCL:3.75μm^j; HCL: 33.79μm^k	IPCN^b; CCDB^b,d; Bharathi et al. (2011)^a,c,e,g; Ghosh et al. (2021)^{a,e,f,h,i,j,k}
M.denudata Clarke, 1879		14^a	-	IPCN ^a
M.dioica Willdenow, 1805	28^a, 56^b		Diploid^c; 2C (flow cytometry): 3.36 pg^d, 2^e-12^f chromosomes with secondary constrictions; CSR: 2.04-3.58μm^g; MCL: 2.75µm^h; HCL: 77.10μmⁱ; 45S (4) and 5S (2) rDNA signals^j	Bharathi et al. (2011)^a,c,e; Xie et al. (2019a)^a,j; Ghosh et al. (2021)^b,d,f,g,h,i
M.foetida Schumacher, 1827	44^a		-	Behera et al. (2011)^a
M.rostrata Zimmermann, 1922	22^a		-	Behera et al. (2011)^a
M.sahyadrica Kattukunnel et Antony, 2007	28^a		2 chromosomes with secondary constrictions^b; CSR: 0.73–1.83µm^c; TCL: 37.53µm^d, MCL: 1.34µm^e	Behera et al. (2011)^a-e
M.subangulata Blume, 1826	56^a		2C (flow cytometry): 3.06pg^b; 8 chromosomes with secondary constrictions^c; CSR: 1.52-3.11μm^d; HCL: 60.30μm^e	Ghosh et al. (2021) ^a-e
M.subangulatasubsp.renigera Don, 1834	56^a		4 chromosomes with secondary constrictions^b; CSR: 0.52-1.26µm^c; MCL: 0.93µm^d; TCL 51.88µm^e	Bharathi et al. (2011) ^a-e
M.tuberosa Miquel, 1855	22^a	11^b	-	IPCN^a,b; CCDB^a,b

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# 2n: Zygotic chromosome number; n: gametic chromosome number; I: univalent; II: bivalent; III: trivalent; CSR: chromosome size range; MCL: mean chromosome length; HCL: total length of haploid set of chromosomes; TCL: total length of diploid set of chromosomes; NOR: nucleolar organizing region, superscripts correspond to references.

Table 4.

Chromosome number and genome size in Bryonieae#.

Genera	Species studied	Chromosome no.			Genome size	References
Genera	Species studied	x	2n	n	Genome size	References
Bryonia		10^a				Darlington and Janaki Ammal (1945) ^a
	B.alba Linnaeus, 1753	10^a	20^b	10^c	2C (flow cytometry): 5827Mbp^d	CCDB^d , Volz and Renner (2008)^a,b,c
	B.aspera Ledebour, 1843	10^a	40^b, 60^c	20^d, 10^e	-	Kumar and Subramaniam (1987)^c, Volz and Renner (2008)^a,b,d,e
	B . cretica Linnaeus, 1753	10^a	60^b	30^c	-	Volz and Renner (2008) ^a,b,c
	B.dioica Jacquin, 1774	10^a	20^b	10^c	2C (microdensitometry): 4.01pg^d; 2C (flow cytometry): 5522Mbp^e	CCDB^d,e, Volz and Renner (2008)^a,b,c
	B.macrostylis Heilbronn et Bilge, 1954			10^a	-	IPCN ^a
	B . marmorata Petit, 1889		40^a	20^b	-	Volz and Renner (2008) ^a,b
	B . monoica Aitchison et Hemsley, 1886	10^a	20^b		-	Volz and Renner (2008) ^a,b
	B.multiflora Boissier et Heldreich, 1849	10^a			-	Volz and Renner (2008) ^a
	B.syriaca Boissier, 1856	10^a	20^b		-	Volz and Renner (2008) ^a,b
	B.verrucosa Aiton, 1789	10^a	20^b	10^c	2C (flow cytometry): 2.09pg^d; 4504Mbp^e	CCDB^d,e, Volz and Renner (2008)^a–c
Ecballium		12^a				Darlington and Janaki Ammal (1945) ^a
	E.elaterium Linnaeus, 1753		18^a	12^b	2C (flow cytometry): 2442Mbp^c	Veselý (2012)^c , Volz and Renner (2008)^b
	E.elateriumsubsp.dioicum Battandier, 1989		18^a, 24^b	9^c, 12^d	-	Volz and Renner (2008) ^a-d
	E.elateriumLinnaeus, 1753subsp.elaterium		18^a	9^b	-	Volz and Renner (2008) ^a,b

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# 2n: Zygotic chromosome number; n: gametic chromosome number.

Table 5.

Cytogenetic information in Sicyoeae#.

Genera studied	Species studied	Chromosome no.			Ploidy, Genome size, Chromosome features	References
Genera studied	Species studied	x	2n	n	Ploidy, Genome size, Chromosome features	References
Cyclanthera Lilja, 1870		8^a				Darlington and Janaki Ammal (1945) ^a
Cyclanthera Lilja, 1870	C.pedata (L.) Schrader, 1831		16^a, 32^b	8^c	Diploid^e	Roy et al. (1991)^a,c,e, Samuel et al. (1995)^b
Echinocystis Torrey et Gray, 1840		8^a		16^b		Bhowmick and Jha (2015b)^b, Darlington and Janaki Ammal (1945)^a
	E.lobata Michaux, 1803		16^a, 32^b		Tetraploid^c; 2C (flow cytometry):1.49pg^d	IPCN^a,b, Plant DNA C-Values Database ^c,d
	E.macrocarpa Greene, 1885		32^a		-	Whitaker (1950) ^a
Echinopepon Naudin, 1866	E.wrightii Gray, 1853			12^a	-	IPCN^a, CCDB^a
Frantzia				12^a, 14^b	-	Schaefer and Renner (2011)^a,b
Hodgsonia Persson, 1953	H.macrocarpavar.capniocarpa Ridley, 1920		18^a		-	IPCN^a, CCDB^a
Luffa		13^a				Darlington and Janaki Ammal (1945) ^a
	L.acutangula	13^a	26^b	13^c	Diploid^d; CSR:1.39–3.20μm^e; 18m+2sm+6m.st^f; NORs:6^g; distal DAPI and nucleolar CMA signals^h	Kumar and Subramaniam (1987)^a,b, IPCN^c, Bhowmick and Jha (2021)^b,d-h
	L.acutangulavar.acutangula			13^a	-	Beevy and Kuriachan (1996) ^a
	L.acutangulavar.amara Clarke, 1879			13^a	-	Beevy and Kuriachan (1996) ^a
	L.aegyptiaca (syn L.cylindrica Roemer, 1846)	13^a	26^b	13^c	Diploid^d, 2C (flow cytometry): 1.56 pg^e; 2C (Feulgen densitometry): 1.7pg^f; CSR: 1.60–2.06μm^g; 24M+1sm^h; 22m+ 4m.stⁱ; NORs:2^j; nucleolar and distal CMA signals^k; 45S (10) and 5S (2) rDNA signals^l	Bennet et al. (1982)^b,d,f, Kumar and Subramaniam (1987)^a,b, Waminal and Kim (2012)^b,d,g,h,l, Bhowmick and Jha (2015a)^{b,c,d,e,i,j,k}
	L.echinata		26^a, 39^b, 52^c	13^d	Diploid^e; CSR 2.44–3.96 μm^f; 16m+4sm+6m.st^g; NORs: 6^h; Distal and intercalary DAPI and nucleolar CMA signalsⁱ	Kumar and Subramaniam (1987)^a-e, Bhowmick and Jha (2021)^a,e-i
	L.graveolens Roxburgh, 1832	13^a			-	Kumar and Subramaniam (1987) ^a
	L.hermaphrodita Singh et Bhandari, 1963			13^a	-	IPCN ^a
	L.operculata Linnaeus, 1759	13^a	26^b	13^c	-	Kumar and Subramaniam (1987)^a,b, IPCN^c
Sicyos (75, includes Sechium, Microsechium)		12^a	24^b		-	Darlington and Janaki Ammal (1945) ^a,b
	S.angulatus	12^a	24^b		Diploid^c; CSR: 1.9-4.6µm^d; 4 adjacent 45S+5S rDNA signals^e	Waminal and Kim (2015)^a-e; IPCN^b
	S.australis Endlicher, 1833		24^a, 26^b		12II^c, 13II^d	IPCN^a-d, CCDB^a-d
	S.edulis Jacquin, 1760 (syn of Sechiumedule)	13^a	26^b, 28^c	12^d, 13^e	Diploid^f; metacentric and submetaccentric chromosomes^g; CSR: 2.69–5.38µm^h; 45S (6), 5S (2) rDNA and telomeric repeat signals (28)ⁱ	Beevy and Kuriachan (1996)^a,b,e, Pellerin et al. (2018)^c,f,g,h,i, Ting et al. (2019)^c, IPCN^d, CCDB^d
	S.nihoaensis St. John, 1970			12^a	-	IPCN^a, CCDB^a
	Sechiumcompositum Smith, 1903 (syn. Microsechiumcompositum)			14^a	-	IPCN^a, CCDB^a
	S.hintonii Wilson, 1958 (syn Microsechiumhintonii)			14^a	-	IPCN^a, CCDB^a
Trichosanthes (100)		11^a				Darlington and Janaki Ammal (1945) ^a
	T.anaimalaiensis Beddome, 1864		22^a	11^b	-	Beevy and Kuriachan (1996) ^a,b
	T.boninensis Nakai et Tuyama, 1928		22^a		-	IPCN ^a
	T.bracteata Lamarck, 1797	11^a	22^b, 44^c, 66^d		-	Kumar and Subramaniam (1987)^a,b, Roy et al. (1991)^c,d
	T.bracteatavar.bracteata			11^a, 22^b	-	Beevy and Kuriachan (1996) ^a,b
	T.chingiana Handel-Mazzetti, 1936		22^a		-	IPCN ^a
	T.costata Blume, 1826 (syn Gymnopetalumchinense Loureiro, 1790)		22^a		Diploid^b; 45S (6) and 5S (4) rDNA signals^c	Kumar and Subramaniam (1987)^a, Xie et al. (2019a)^b,c
	T.cucumerina		22^a	11^b	Diploid^c; 12m+4M+2sm+4sm.st^d; CSR: 2.26–4.99µm^e; 6 chromosomes with double constrictions^f; NORs: 4^g; nucleolar CMA and distal DAPI bands^h	Bhowmick and Jha (2019) ^a-h
	T.cucumerinassp.cucumerina Anguina	11^a	22^b	11^c, 22^d, 32^e, 33^f	Diploid^e; 2C (Feulgen densitometry): 2.2pg^f; CSR: 2.77–5.01μm^g; 12m+4M+2sm+4sm.st^h; 6 chromosomes with double constrictionsⁱ; NORs: 4^j; nucleolar and distal CMA bands^k; 45S (6) and 5S (2) rDNA signals^l	Kumar and Subramaniam (1987)^a, Bhowmick and Jha (2019)^{b,c,e,g,h,i,j,k}, Xie et al. (2019a)^b,l, IPCN^c-f
	T.dioica	11^a	22^b	11^c	Diploid^d; 2C (flow cytometry): male-2.27pg, female- 2.32 pg^e; 12m+6Sm +2St+2Sm.t^f; distal DAPI bands^g; distal CMA bands in females^h; 1 rod bivalent in meiosisⁱ	Kumar and Subramaniam (1987)^a, Guha et al. (2004)^b,d,f,h, Bhowmick and Jha (2015a)^{b,c,d,e,f,g,h,i}
	T.dunniana Léveillé, 1911		22^a		Diploid^b; 45S (6) and 5S (2) rDNA signals^c	Xie et al. (2019a) ^a-c
	T.himalensis Clarke, 1879			11^a	-	Roy et al. (1991) ^a
	T.hupehensis Cheng et Yueh, 1974		22^a		-	IPCN^a, CCDB^a
	T.kirilowii Maximowicz, 1859		60^a, 66^b, 88^c, 110^d		Hexa-, octa-, decaploid^e;CSR: 2.3-3.5μm^f; 45S (4), 5S (4) and 45S +5S (6) adjacent rDNA signals^g	IPCN^a, CCDB^a, Waminal and Kim (2015)^b,c,d,e-g
	T.kirilowiivar.japonica			11^a	-	Roy and Saran (1990)^a
	T.lepiniana Naudin, 1868		44^a	11^b	1 B^c	Roy et al. (1991)^b,c, IPCN^a, CCDB^a
	T.lobata Roxburgh, 1832	11^a		11^b	-	Kumar and Subramaniam (1987)^a, Beevy and Kuriachan (1996)^b
	T.mianyangensis Yueh et. Liao, 1992		88^a		-	IPCN^a, CCDB^a
	T.nervifolia Linnaeus, 1753			11^a	-	Beevy and Kuriachan (1996) ^a
	T.ovigera Blume, 1826		22^a		Diploid^b; 45S (10) and 5S (2) rDNA signals^c	Xie et al. (2019a) ^a-c
	T.palmata Linnaeus, 1759		22^a, 44^b, 66^c	11^d		IPCN ^a-d
	T.pedata Merril et Chun, 1934		22^a		-	IPCN^a, CCDB^a
	T.truncata Clarke, 1879		22^a		-	IPCN^a, CCDB^a
	T.wallichiana Wight, 1840	11^a	22^b		-	Kumar and Subramaniam (1987) ^a,b

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#x: base number; 2n: zygotic number; n: gametic number; NOR: nucleolar organizing region; B: B chromosome; II: bivalents; superscripts correspond to references.

Table 6.

Cytogenetic information on Benincaseae#.

Genera studied	Species studied	Chromosome no.			Ploidy, Genome size, Chromosome features	References
Genera studied	Species studied	x	2n	n	Ploidy, Genome size, Chromosome features	References
Benincasa	B.fistulosa		24^a		Diploid^b; 45S (4) and 5S (4) signals^c	Li et al. (2016) ^a,b,c
Benincasa	B.hispida	12^a	24^b	12^c	Diploid^d; 2C (flow cytometry):1.97pg^e, 2C (feulgen densitometry):2.1pg^f; CSR 2.54-4.59µm^g; 16m+6Sm+2Sm.t^h; NORs:2ⁱ; distal CMA signals^j; 45S (2) and 45S+5S (2) adjacent rDNA signals^k	Plant DNA C-Values Database^f, Waminal et al. (2011)^b,d,g,k, Bhowmick and Jha (2015a)^{b,c,d,e,h,i,j}
Citrullus		11^a				Darlington and Janaki Ammal (1945) ^a
	C.amarus (syn. C.lanatusvar.citroides)	11^a	22^b		Diploid^c; CSR: 3.1–4.7μm^d; 45S (2) and 5S (4) rDNA signals^e	Reddy et al. (2013)^b-d, Waminal and Kim (2015)^a-e, Renner et al. (2017)^b
	C.colocynthis		22^a	11^b	Diploid^c; 45S (2) and 45S+5S (2) adjacent rDNA signals^d	Beevy and Kuriachan (1996)^b, Reddy et al. (2013)^a,c,d, Li et al. (2016)^a,c,d
	C.ecirrhosus		22^a	11^b	Diploid^c; 2 satellites detected in meiosis^d; 45S (2) and 5S (4) rDNA signals^e; regular meiosis^f	Li et al. (2016)^a,c,e, Renner et al. (2017)^a,b,c,d,f
	C.lanatus		22^a	11^b	Diploid^c; CSR: 1.09μm-1.72μm^d; 14m+8sm^e; 45S (2) and 45S+5S (2) adjacent rDNA signals^f; linkage groups hybridized to chromosomes^g	Beevy and Kuriachan (1996)^b, Waminal et al. (2011)^a,c,d,e,f, Ren et al. (2012)^a,c,g
	C.lanatussubsp.lanatus		22^a		Diploid^b; 45S (2) and 5S (4) rDNA signals^c	Li et al. (2016) ^a-c
	C.lanatussubsp.mucosospermus Fursa, 1972		22^a		Diploid^b; 45S (2) and 45S+5S (2) adjacent rDNA signals^c	Li et al. (2016) ^a-c
	C.lanatussubsp.vulgaris Schrader, 1836		22^a		Diploid^b; 45S (2) and 45S+5S (2) adjacent rDNA signals^c	Li et al. (2016) ^a-c
	C.lanatusvar.lanatus		22^a		Diploid^b; 45S (2) and 45S+5S (2) adjacent rDNA signals^c	Reddy et al. (2013) ^a-c
	C.naudinianus (syn Acanthosicyosnaudinianus)		24^a		Diploid^b; 45S (2) and co-localized 45S+5S (2) rDNA signals^c	Li et al. (2016) ^a,b,c
	C.rehmii		22^a		Diploid^b; 45S (2) and 5S (2) rDNA signals^c	Reddy et al. (2013)^a-c, Li et al. (2016)^a-c
	C.vulgaris Schrader, 1836		22^a, 44^b	11^c	Diploid^d; 2C: 0.88/0.90pg^e	IPCN^a,c,d, Arumuganathan and Earle (1991)^e
Coccinia (30)		12^a				Darlington and Janaki Ammal (1945) ^a
	C.abyssinica Lamarck, 1753	12^a	24^b		-	Kumar and Subramaniam (1987)^a, Roy et al. (1991)^b
	C.grandis	12^a	24^b	12^c	Diploid^d, 2C (Flow cytometry): male- 0.943^e/0.92^f pg and female- 0.849^g/ 0.73^h pg; CSR: 1.33-4.71μm (male) and 1.35-2.26µm (female)ⁱ; 15m+4M+2sm+2m:sm+1m:st (Y) in male and 14m+6M+2sm+2m:st in female^j; NORs-2^k; chromosomal C bands^l; centromeric, nucleolar CMA bands^m; 45S (4)ⁿ rDNA signals, 2 signals adjacent to 5S^o; GISH performed^p; repetitive, organellar DNA hybridized^q; centromere immunofluorescence^r; heteromorphic sex chromosomes (largest Y)^s; X-Y bivalent (meiosis)^t	Bhowmick et al. (2012)^{b,c,d,j,k,m,s,t}, (2016) ^{b,d,f,h,j,k,n,s}, Sousa et al. (2013)^{b,d,e,g,i,k,l,n,o,r,s,t}, Sousa et al. (2017)^{b,d,k,n,o,p,q,r,s}, Xie et al. (2019a)^b,n,o
	C.hirtella Cogniaux, 1896		24^a		Diploid^b; 2C (flow cytometry): male-0.988pg^c; 45S (4) and 45S+5S (2) adjacent rDNA signals^d, repetitive and organellar DNA hybridized^e; centromere immunofluorescence performed^f	Sousa et al. (2017) ^a-f
	C.sessilifolia Sonder, 1881		24^a		Diploid^b; 2C (Flow cytometry): male- 0.984pg, female- 0.998pg^c; 45S (4) and 45S+5S (2) adjacent rDNA signals^d; repetitive and organellar DNA^e; centromere immunofluorescence performed^f	Li et al. (2016)^a,b,d, Sousa et al. (2017)^a–f
	C.trilobata		20^a		Diploid^b; 2C (flow cytometry): male- 1.263pg ^c; 45S (2) and 45S+5S (2) adjacent rDNA signals^d, repetitive, organellar DNA sequence hybridized^e	Sousa et al. (2017) ^a-e
Ctenolepis Hooker, 1867	C.garcinii Burman, 1768		24^a	12^b	-	Kumar and Subramaniam (1987)^a, Beevy and Kuriachan (1996)^b
Diplocyclos Endlicher, 1833	D.palmatus		24^a		Diploid^b; 45S (4) and 45S+5S (2) adjacent rDNA signals^c	Li et al. (2016) ^a-c
Lagenaria Seringe, 1825	L.leucantha Rusby, 1896		22^a	11^b	-	IPCN^a,b, CCDB^a,b
	L.leucanthavar.clavata Makino, 1940		22^a		-	CCDB ^a
	L.siceraria	11^a	22^b	11^c	Diploid^d, 2C (flow cytometry): 0.734pg^e; 2C (Feulgen densitometry):1.4pg^f; CSR: 0.56–1.06μm^g; metacentric and few sub-metacentric chromosomes^h; 45S (2) and 45S+5S (2) adjacent rDNA signalsⁱ	Darlington and Janaki Ammal (1945)^a, Plant DNA C-Values Database^f, Beevy and Kuriachan (1996)^c, Achigan-Dako et al. (2008)^d,e, Waminal and Kim (2012)^b,d,g,h,i, Li et al. (2016)^b,d,i, Xie et al. (2019a)^b,i
	L.sicerariavar.macrocarpa		22^a		-	CCDB ^a
	L.vulgaris Seringe, 1825		22^a	11^b	Diploid^c; 2C (Feulgen densitometry): 1.40pg^d	Bennet et al. (1982)^a,b,c
Melothria		11^a, 12^b				Darlington and Janaki Ammal (1945) ^a,b
	M.pendula Linnaeus, 1753		24^a		Diploid^b; 45S (2) and 45S+5S (2) adjacent rDNA signals^c	Li et al. (2016) ^a-c
	M.perpusilla Blume, 1826		48^a		-	Kumar and Subramaniam (1987) ^a
	M.scabra Naudin, 1866		24^a		-	CCDB ^a
Peponium Engler, 1897	P.betsiliense Keraudren, 1960		24^a		-	CCDB ^a
Solena	S.amplexicaulis Lamarck, 1785 (syn. S.heterophylla, Melothriaheterophylla, Zehneriaumbellata)		22^a, 24^b, 26^c, 36^d, 48^e	11^f, 12^g, 24^h	2-4 Bⁱ	Kumar and Subramaniam (1987)^a,b,c,e, Roy et al. (1991)^d,i, Beevy and Kuriachan (1996)^b,g,h, IPCN^b,d,e,f,g,h
Zehneria	Z.capillacea Jeffrey, 1962 (syn. Melothriacapillacea)		22^a		-	CCDB ^a
	Z.indica Loureiro, 1790 (syn. Melothriajaponica)	11^a	22^b	24^c	Diploid^d; 45S (2) and 45S+5S (2) adjacent rDNA signals^e	Waminal and Kim (2015) ^a,b,d,e
	Z.marlothii Cogniaux, 1962		24^a		Diploid^b; 45S (2) and 45S+5S (2) adjacent rDNA signals^c	Li et al. (2016) ^a,b,c
	Z.maysorensis Wight et Arnott, 1834		48^a	24^b	45S (2) and 5S (2) signals^c	Beevy and Kuriachan (1996)^a,b, Xie et al. (2019a)^a,c
	Z.mucronata Blume, 1856 (syn. Melothriamucronata)		22^a	12^b	-	Darlington et al. (1956)^a, CCDB^b
	Z.scabra Sonder, 1862 (syn. Melothriapunctata)		24^a, 48^b		-	CCDB^a, Kumar and Subramaniam (1987)^b
	Z.thwaitesii Schweinfurth, 1868		44^a		-	CCDB ^a

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# genera included other than Cucumis; x: base number; 2n: zygotic number; n: gametic number; NOR: nucleolar organizing region; B: B chromosome; II: bivalents; IPCN: Index to Plant Chromosome Number Reports; CCDB: Chromosome Counts Database; superscripts correspond to references.

Table 7.

Cytogenetic features of Cucumis (Benincaseae)#.

Species with subspecies/ varieties				Chromosome no.			Ploidy, Genome size, Chromosome features	References
Species with subspecies/ varieties				x	2n	n	Ploidy, Genome size, Chromosome features	References
C.aculeatus Cogniaux, 1895					48^a		Allotetraploid^b; 24II^c	IPCN^a-c, CCDB^a-c
C.africanus Linnaeus, 1782				12^a	24^b, 48^c	12^d	Diploid^e; 2C (Feulgen microdensitometry): 1.782pg^f; 4 satellited chromosomes^g; 45S (4^h/6ⁱ) rDNA signals, 2 co-localized 45S+5S signals^j	IPCN^b,c, Yadava et al. (1984)^b,d, Ramachandran and Narayan (1985)^b,e,f, Yagi et al. (2015)^a,b,g,i,j, Zhang et al. (2016)^b,e,h,j
C.angolensis Cogniaux, 1881.					24^a			IPCN ^a
C.anguria Linnaeus, 1753					24^a		Diploid^b; majorly submetacentric and few nearly metacentric chromosomes^c; 1 pair satellited^d; 45S (2) and co-localized 45S+5S (2) rDNA signals^e, ScgCP enables chromosome identification^f; GISH reveals cross species relationships^g	Singh and Roy (1974)^a-d, Zhang et al. (2015)^a,g, (2016)^b,e, Li et al. (2018)^a,f
			C.anguriavar.anguria	12^a	24^b	12^c	Diploid^d; 4 satellited chromosomes^e; 45S (2) and co-localized 45S+5S (2) rDNA signals^f	Yadava et al. (1984)^b,c, Yagi et al. (2015)^a,d,e,f
			C.anguriavar.longipes		24^a	12^b	Diploid^c; 2C (Feulgen microdensitometry): 1.587pg^d	Yadava et al. (1984)^a,b, Ramachandran and Narayan (1985)^a,c,d
			C.anguriavar.longaculeatus	12^a	^12.5		Diploid^c; 4 satellited chromosomes^d; 45S (2) and co-localized 45S+5S (2) rDNA signals^e	Yagi et al. (2015) ^a-e
C.asper Cogniaux, 1901					24^a		Diploid^b; 45S (4) and 5S (2) signals detected^c	IPCN^a, Zhang et al. (2016)^a,b,c
C.callosus Rottler, 1803					14^a, 24^b	12^c	Diploid^d; 2C (Feulgen microdensitometry):1.590pg^e; 11m+1sm (haploid)^f	Ramachandran and Narayan (1985)^a,d,e, Rajkumari et al. (2013)^b,c, (2015)^b,c,f
C.cinereusCogniaux, 1901 (syn. Cucumellacinerea)							2C (Feulgen microdensitometry): 0.5pg^a	Bennet et al. (1982)^a
C.diniae Raamsdonk et Visser, 1992					48^a		-	IPCN ^a
C.dinteri Cogniaux, 1901					24^a		Diploid^b; 2C (Feulgen microdensitometry): 2.167pg^c	IPCN^a, Ramachandran and Narayan (1985)^a-c
C.dipsaceus Spach, 1838					24^a	12^b	Diploid^c; 2C (Feulgen microdensitometry): 2.448pg^d; 2m+8sm+2st (haploid)^e; 45S (2) and co-localized 45S+5S (2) rDNA signals^f	Yadava et al. (1984)^a,b, Ramachandran and Narayan (1985)^a,c,d, Rajkumari et al. (2015)^a,c,e, Zhang et al. (2016)^a,c,f
C.ficifoliusRichard, 1847					24^a, 48^b	12^c	Diploid^d; 2C (Feulgen microdensitometry):1.373pg^e; 45S (2) and co-localized 45S+5S (2) rDNA signals^f	Yadava et al. (1984)^a,c, Ramachandran and Narayan (1985)^a,d,e, Zhang et al. (2016)^b,f
C.figarei Naudin, 1859					48^a, 72^b		Autoallopolyploid^c; 2C (Feulgen microdensitometry): 3.886pg^e; 36II^f	IPCN^a-f, Ramachandran and Narayan (1985)^a,c,e
C.heptadactylis Naudin, 1859					48^a	23^b, 24^c, 52^d	Autotetraploid^e; 2C (Feulgen microdensitometry): 2.225pg^f; 8 satellited chromosomes^g; 45S (8) rDNA signals^h of which 4 co-localized to 5S signalsⁱ or separate 5S (4) rDNA signals^j; 10IV+4II^k; irregular meiosis^l	IPCN^a,e,k, Yadava et al. (1984)^a,b,d,e,l, Ramachandran and Narayan (1985)^a,e,f, Yagi et al. (2015)^a,e,g,h,i, Zhang et al. (2016)^a,e,h,j
C.hookeri Naudin, 1870					24^a	12^b	Diploid^c	Yadava et al. (1984) ^a,b,c
C.humifructus Stent, 1927					24^a		Diploid^b; 2C (Feulgen microdensitometry): 2.455 pg^c	Ramachandran and Narayan (1985) ^a,b,c
C.hystrix Chakravarty, 1952				12^a	24^b		Diploid^c; 2m+10sm (haploid)^d; 45S (4) and co-localized 45S+5S (2) rDNA signals^e; FISH with bulked oligo probe from cucumber chromosome C7^f, GISH reveals cross species relationships^g	Rajkumari et al. (2015)^b,c,d, Han et al. (2015)^f, Zhang et al. (2015)^b,g, (2016)^a,b,c,e
C.indicus Ghebretinsae et Thulin, 2007					20^a		Diploid^b; 4m+ 6sm (haploid)^c	Rajkumari et al. (2015) ^a-c
C.javanicus Miquel, 1856 (syn. Melothriaassamica)				12^a	24^b, 48^c		-	Kumar and Subramaniam (1987)^a, CCDB^b,c
C.leiospermus Wight et Arnott, 1834 (syn. Melothrialeiosperma)					24^a		-	CCDB ^a
C.leptodermis Schweickerdt, 1933					24^a	12^b	-	Yadava et al. (1984) ^a,b
C.longipes Hooker, 1871					24^a		-	IPCN ^a
C.meeusei Jeffrey, 1965					48^b	22^c, 24^d	Tetraploid^e; 2C- 3.203pg (Feulgen microdensitometry)^f; 45S (6) and co-localized 45S+5S (2) rDNA signals^g	Yadava et al. (1984)^b,c,d, Ramachandran and Narayan (1985)^b,e,f, Zhang et al. (2016)^b,e,g
C.melo Linnaeus, 1753				12^a	20^b, 22^c, 24^d	12^e	Diploid^f; 2C (Feulgen photometry) : 0.94-1.04pg^g, 1.90pg^h; 2C (Flow cytometry): 1.05pgⁱ; 14m+10st (2SAT)^j; 7m+5sm (haploid)^k; 4 satellites^l or 2 satellites^m; CSR1.0-2.1μmⁿ; CMA bands detected^o; 45S (2) and co-localized 45S+5S (2) rDNA signals^p; centromeric, telomeric, nulceolar and SSR probe hybridization reveals chromosomal relation^q; ScgCP applied for comparative chromosome rearrangement studywith C.sativus^r; FISH with bulked oligo probe from cucumber chromosome C7^s; novel centromeric satellite DNA hybridized on chromosomes^t; GISH reveals cross species relationships^u; infraspecific positional differences in 45S (terminal and interstitial) -5S (terminal, subterminal and interstitial) rDNA signals^v	CCDB^b,c, Plant DNA C-Values Database^h, Kumar and Subramaniam (1987)^a, Arumuganathan and Earle (1991)^g, Marie and Brown (1993)ⁱ, Zhang (2005)^d,f,j,u, (2015)^d,t, Song and Kim (2008)^d,f,m, Han et al. (2009)^d,e,f,q, (2015)^s, Liu et al. (2010)^d,f,q, Hoshi et al. (2013)^d,f,l,n,o,p, Lou et al. (2014)^r, Rajkumari et al. (2013)^d,e, (2015)^d,f,k, Setiawan et al. (2018)^d,v, (2020)^d,t
			C.melosubsp.melo	12^a	24^b		Diploid; 45S (4) and 5S (2) rDNA signals^c	Zhang et al. (2016) ^a-c
			C.melosubsp.agrestis Naudin, 1859	12^a	24^b		Diploid; 45S (4) and 5S (2) rDNA signals^c	Zhang et al. (2016) ^a-c
			C.melovar.agrestis	12^a	24^b	12^c	Diploid^d; 2C (Feulgen microdensitometry): 2.483pg^e; 10m+2sm (haploid)^f; 1 pair satellited^g	Singh and Roy (1974)^b,d,g, Yadava et al. (1984)^a-d, Ramachandran and Narayan (1985)^b,d,e, Beevy and Kuriachan (1996)^b,c, Rajkumari et al. (2015)^b,d,f
			C.melovar.conomon Thunberg, 1780		24^a		Diploid^b; 7m+3sm+2st (haploid)^c	Zhang et al. (2005)^a, Rajkumari et al. (2015)^a,b,c
			C.melovar.flexuosus Linnaeus, 1763		24^a		-	IPCN ^a
			C.melovar.inodorus Jacquin, 1832		24^a		Diploid^b; 2C (flow cytometry): 0.64pg^c	Karimzadeh et al. (2010) ^a-c
			C.melovar.melo		24^a	12^b	Diploid^c; 4m+8sm (haploid)^d	Beevy and Kuriachan (1996)^a,b, Rajkumari et al. (2015)^b,c,d
			C.melovar.momordica Roxburgh, 1832		24^a	12^b	Diploid^c; 2C (Feulgen microdensitometry): 2.291pg^d; 6m+5sm+1st (haploid)^e	Yadava et al. (1984)^a,b, Ramachandran and Narayan (1985)^a,c,d, Rajkumari et al. (2015)^a,c,e
			C.melovar.muskmelon		24^a	12^b		Yadava et al. (1984) ^a,b
			C.melovar.utilissimus Roxburgh, 1832		24^a	12^b	Diploid^c; 2C (Feulgen densitometry): 2.358 pg^d	Yadava et al. (1984)^a,b; Ramachandran and Narayan (1985)^a,c,d
C.membranifolius Hooker, 1871					48^a	24^b	-	Yadava et al. (1984) ^a,b
C.metulifer Naudin, 1859 (syn. C.metuliferus)					24^a	12^b	Diploid^c; 2C (Feulgen microdensitometry): 2.391pg^d; metacentric, submetacentric, subtelocentric chromosomes^e; CSR: 0.9–2.0 μmf; 4 satellites^g; nucleolar and centromeric CMA-DAPI bands^h; 45S (2) and co-localized 45S+5S (2) rDNA signalsⁱ, satellite sequences^j and telomeric DNA^k hybridized on chromosomes; ScgCP applied for comparative chromosome rearrangement studywith C.sativus^l; GISH reveals cross species relationships^m	Yadava et al. (1984)^a,b,c, Ramachandran and Narayan (1985)^a,c,g, Ramachandran and Narayan (1990)^a,c,i, Hoshi et al. (2013)^a,c,e,f,g,h, Lou et al. (2014)^l, Yagi et al. (2014)^{a,c,g,h,i,j,k}, Li et al. (2016)^a,c,i, Zhang et al. (2015)^a,m, (2016)^a,c,i
C.myriocarpus					24^a	12^b	Diploid^c; 45S (2^d/4^e) and co-localized 45S+5S (2)^f rDNA signals^d	CCDB^a; Zhang et al. (2016)^a,b,c,d,f, Yagi et al. (2015)^a-f
			C.myriocarpussubsp.leptodermis Schweickerdt, 1933	12^a	24^b		Diploid^c; 4 satellited chromosomes^d; 45S (3^e, 2^f) and co-localized 45S+5S (2^g) rDNA signals	Yagi et al. (2015) ^a-g
			C.myriocarpusvar.myriocarpus	12^a	48^b		Tetraploid^c; 8 satellited chromosomes^d; 45S (4) and co-localized 45S+5S (4) rDNA signals^e	Yagi et al. (2015) ^a-e
C.prophetarum Linnaeus, 1755					24^a	12^b	Diploid^c, 2C (Feulgen Microdensitometry): 1.656 pg^d 5m+7sm (haploid)^e	Ramachandran and Narayan (1985)^a,c,d, Rajkumari et al. (2013)^a,b, (2015)^a,c,e
	C.prophetarumsubsp.zeyheri Sonder, 1862				48^a		-	IPCN ^a
C.pubescens Willdenow, 1805					24^a	12^b	-	IPCN^a; Beevy and Kuriachan (1996)^b
C.pustulatus Hooker, 1871					48^a, 72^b	24^c	Hexaploid^d, 45S (8) and co-localized 45S+5S (2) rDNA signals^e; FISH with bulked oligo probe from cucumber chromosome C7^f	Yadava et al. (1984)^a,c, Han et al. (2015)^f, Zhang et al. (2016)^b,d,e
C.ritchiei Clarke, 1879					24^a		Diploid^b, 8m+4sm (haploid)^c	Rajkumari et al. (2015) ^a,b,c
C.sagittatus Peyritsch, 1860					24^a	12^b	Diploid^c, 2C (Feulgen microdensitometry):1.571pg^d	Yadava et al. (1984)^a,b, Ramachandran and Narayan (1985)^a,c,d
C.sativus Linnaeus, 1753				7^a	14^b	7^c	Diploid^d, 2C (flow cytometry): 1.03pg^e /1.77pg^f; 12 metacentric and 2 sub-metacentric chromosomes^g; CSR: 0.83-1.01μm^h, chromosomal C-bandsⁱ; centromeric 45S (10) and distal 5S (2) rDNA signals^j; FISH with centromeric and telomeric^k and SSR probe reveals chromosome evolution^l; high resolution molecular cytogenetic map^m; ScgCP applied for cross species chromosome rearrangement studyⁿ; FISH with bulked oligo probe from cucumber chromosome C7 in comparison with 5 Cucumis species^o; GISH reveals cross species relationships^p	Kumar and Subramaniam (1987)^a,b, Marie and Brown (1993)^f, Beevy and Kuriachan (1996)^b,c, Hoshi et al.(2008)^b,d,i, Barow and Meister (2003)^b,d,e, Han et al (2011)^b,d,k,l,m, Liu et al. (2010)^b,l, Waminal and Kim (2012)^b,d,g,h,j, Rajkumari et al. (2013)^b,c,f, Sun et al. (2013)^b,m, Lou et al. (2014)^b,n, Han et al. (2015)^o, Zhang et al. (2015)^b,p, Li et al. (2016)^b,d,j
		C.sativus var. Hokutosei		7^a	14^b		Diploid^c, 12 metacentric, 2 sub-metacentric chromosomes^d; centromeric and telomeric signals^e	Zhang et al. (2012) ^a-e
		C.sativusvar.hardwickii Royle, 1835		7^a	14^b		Diploid^c; 2C (Feulgen Microdensitometry): 1.798pg^d; 6m+1sm (haploid)^e; centromeric 45S (6) and intercalary 5S (2) rDNA signals^f, centromeric, telomeric and SSR probe hybridization^gh; molecular cytogenetic mapⁱ	Ramachandran and Narayan (1985)^b,d, Zhao et al. (2011)^b,c,f,g, Yang et al. (2012)^b,h, Rajkumari et al. (2015)^b,c,e, Zhang et al. (2016)^a,b,c,f
		C.sativusvar.hardwickii Royle, 1835		7^a	14^b
		C.sativus var. Long green		7^a	14^b		Diploid^c, 12 metacentric, 2 sub-metacentric chromosomes^d; centromeric and telomeric sequence signals^e	Zhang et al. (2012) ^a-e
		C.sativusvar.sativus (CSS)		7^a	14^b		Diploid^c, centromeric 45S (10) and intercalary 5S (2) rDNA signals^d; centromeric and distal repetitive sequence probes^e; molecular cytogenetic map^f	Zhao et al. (2011)^b-e, Yang et al. (2012)^b,f, Zhang et al. (2016)^a-d
		C.sativus cv. Winter Long			14^a	7^b	Diploid^c, C- banding^d, DAPI banding^e, 45S (6) and 5 S (2) rDNA signals^f, repetitive sequence based molecular karyotype in somatic and pachytene chromosomes^g	Koo et al. (2002)^a-f, (2005)^a,b,g
		C.sativusvar.xishuangbannesis Qi et Yuan Zhenzhen, 1983		7^a	14^b		Diploid^c, centromeric 45S (10) and intercalary 5S (2) rDNA signals^d; centromeric and telomeric signals^e	Zhao et al. (2011)^b,c,e, Zhang et al. (2016)^a-d
C.setosus Cogniaux, 1881					24^a	12^b	Diploid^c; 4m+5sm+3st (haploid)^d	Rajkumari et al. (2013)^a-c, (2015)^a,c,d
C.silentvalleyii Manilal et Sabu et Mathew, 1985					24^a	12^b	-	Rajkumari et al. (2013) ^a,b
C.trigonus Roxb.					24^a	12^b	-	Rajkumari et al. (2013) ^a,b
C.zambianus Widrl., J.H.Kirkbr., Ghebret. and K.R.Reitsma				12^a	24^b		Diploid^c; 45S (2) and co-localized 45S+5S (2) signals^d	Zhang et al. (2016) ^a-d
C.zeyheri Sond.					24^a, 48^b		Diploid^c, Allotetraploid^d; 2C (Feulgen densitometry): 1.682^e/2.846 pg^f; 4 satellites^g; 45S (2) and co-localized 45S+5S (2) rDNA signals^h; FISH with bulked oligo probe from cucumber schromosome C7ⁱ; 24II^j , 12II^k, 11II+2I^l	IPCN^a,b,d,j,k,l, Ramachandran and Narayan (1985)^a-f, Han et al. (2015)ⁱ, Yagi et al. (2015)^a,c,g,h
Cucumellacinerea (Cogn.) C.Jeffrey							2C (Feulgen Microdensitometry): 0.50pg^a	Bennet et al. (1982)^a
Mukiamaderaspatana (L.) M.Roem. (syn. Cucumismaderaspatanas and Melothriamaderaspatana)				12^a	24^b	11^c, 12^d	-	CCDB^b,c, Rajkumari et al. (2015)^b,d
Oreosyceafricana Hook.f. (syn. Cucumissubsericeus)				12^a	48^b		Tetraploid^c; co-localized 45S and 5S rDNA signals (2)^d; FISH with bulked oligo probe from cucumber chromosome C7^e	Han et al. (2015)^e, Zhang et al. (2016)^a-d

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#x: base number; 2n: zygotic number; n: gametic number; NOR: nucleolar organizing region; SAT: satellite chromosome; ScgCP: Single-copy gene-based chromosome painting (Lou et al. 2014); I: univalent, II: bivalent, IV: tetravalent; CCDB: Chromosome Counts Database; superscripts correspond to reference.

Table 8.

Cytogenetic information in Cucurbiteae #.

Genera studied	Species studied	Chromosome no.			Ploidy, Genome size, Chromosome features	References
Genera studied	Species studied	x	2n	n	Ploidy, Genome size, Chromosome features	References
Cayaponia Silva Manso, 1836	C.laciniosa Linnaeus, 1753		24^a		-	Kumar and Subramaniam (1987) ^a
Cucurbita		10^a, 12^b			-	Darlington and Janaki Ammal (1945) ^a,b
	C.andreana Naudin, 1896		40^a			CCDB ^a
	C.argyrosperma Huber, 1867 (syn. C.mixta Pangalo, 1930)		40^a		2C (flow cytometry): 0.748 pg^b	Sisko et al. (2003)^a,b
	C.cylindrata Bailey, 1943		40^a	20^b	-	CCDB ^a,b
	C.digitata Gray, 1853	10^a, 12^b	40^c	20^d	-	Darlington and Janaki Ammal (1945)^a,b, CCDB^c,d
	C.ecuadorensis Cutler et Whitaker, 1969				2C: 0.72pg^a	Plant DNA C Value database^a
	C.ficifolia Bouché, 1837 (syn. C.melanosperma Gasparrini, 1847)		40^a		2C (flow cytometry): 0.933pg^b	Plant DNA C- Values Database^a,b
	C.foetidissima Kunth, 1817	10^a, 12^b	40^c, 42^d		2C (flow cytometry): 0.686pg^e	Darlington and Janaki Ammal (1945)^a,b, Plant DNA C- Values Database^c,e, CCDB^c,d
	C.indica (unresolved)		40^a		-	IPCN ^a
	C.lundelliana Bailey, 1943			20^a	2C (flow cytometry): 0.72pg^b	CCDB^a, Plant DNA C Value database^b
	C.maxima Duchesne, 1786	20^a	24^b, 40^c, 44^d, 48^e	20^f		Kumar and Subramaniam (1987)^a,c,d,e, Beevy and Kuriachan (1996)^f, CCDB^c,f
	C.moschata Duchesne, 1786	10^a, 12^b	24^c, 40^d, 44^e,48^f		Diploid^g; 2C (Feulgen microdensitometry): 0.90pg^h; 2C (flow cytometry): 0.708ⁱ/ 0.97^jpg; 36 metacentric and 4 sub-metacentric chromosomes^k; CSR: 1.05-1.78μm^l, 45S (10) and 5S (4) rDNA signals^m	CCDB^f, Plant DNA C- Values Database^h,i, Kumar and Subramaniam (1987)^a-f, Barrow and Meister (2003)^j, Xu et al. (2007)^d,m, Waminal et al. (2011)^g,d,k,l,m
	C.okeechobeensisssp.martinezii Bailey, 1943		40^a		2C (flow cytometry): 0.74pg^b	Plant DNA C- Values Database^a,b
	C.palmata Watson, 1876	10^a, 12^b	40^c, 42^d	20^e	-	Kumar and Subramaniam (1987)^a,b, CCDB^c,d,e
	C.pedatifolia Bailey, 1943		40^a		-	CCDB ^a
	C.pepo Linnaeus, 1753	10^a, 12^b	22^c, 24^d, 28^e, 40^f, 42^g, 44^h, 46ⁱ, 80^j	20^k	2C (flow cytometry): 0.74pg^l; 0.864^m; 1.109 pg-1.064 pgⁿ; 1.18pg^o; 45S (10) and 5S (4) rDNA signals^p	Kumar and Subramaniam (1987)^a-j, CCDB^f,k, Marie and Brown (1993)^l, Barow and Meister (2003)^o, Rayburn (2008)ⁿ, Plant DNA C- Values Database^m, Xie et al. (2019b)^{f, p}
Sicana Naudin, 1862	S.odorifera Vellozo, 1831		40^a	20^b	-	IPCN ^a,b

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# x: base number; 2n: zygotic number; n: gametic number; CCDB: Chromosome Counts Database; superscripts correspond to references.

Nuclear genome contents

Nuclear genome sizes are reported in 49 species (~5% of total species) belonging to 15 genera (~16% of total genera) of Cucurbitaceae. Among the understudied tribes, 2C genome content is known for one species each from Gomphogyneae and Coniandreae (Table 2). Within the Momordiceae species of India, significant interspecific genome size differences have been reported (Ghosh et al. 2021). The species differed 5.19-fold in their genome sizes (2C = 0.72-3.74 pg) (Table 3) (Ghosh et al. 2021). Interestingly, the species with lowest chromosome number (M.cymbalaria, 2n = 18) contained highest nuclear DNA content among the four Momordica species (Table 3). In Bryonieae, flow cytometric genome size of Bryonia shows a 2.2-fold increase than Ecballium (Table 4). In case of Sicyoeae, flow cytometric 2C DNA content ranges from 1.49–2.32 pg/2C, indicating 1.55-fold differences in genome size. Echinocystislobata Michaux, 1803, in spite of tetraploid condition, shows lowest genome size (Table 5). There is no significant difference in genome size between the genders of Trichosanthesdioica Roxburgh, 1832 (Table 5). Genome size estimates are known from 24 Benincaseae species of which 17 species belong to Cucumis (Tables 6, 7). Highest 2C nuclear genome is known in Benincasahispida Thunberg, 1784 (1.97 pg) (Bhowmick and Jha 2015a) while the lowest is known in Cucumismelovar.inodorus Harz, 1885 (0.64 pg) (Karimzadeh et al. 2010). In case of Cucumis, there is yet no consensus on whether the taxa with different base numbers (x = 7, 12) have correspondingly dissimilar genome sizes since the researchers depended on diverse methods of genome size estimation. Lower 2C genome size was reported in C. Cocciniagrandis Linnaeus, 1767 (2n = 24) while C.trilobata (2n = 20) had higher 2C DNA content (Table 6). The divergence in genome size between genders was found to be highest in dioecious C.grandis (Table 6), a sharp contrast to dioecious Trichosanthesdioica (Table 5). Benincaseae shows a 3.07-fold overall difference in genome size. Genome sizes are known in eight species of Cucurbita Jussieu, 1789. Flow cytometric genome size ranges from 0.686–0.933 pg/2C, indicating a 1.36-fold variation (Table 8). Despite polypoidy, the nuclear DNA content of Cucurbita species is comparable to many diploids.

Karyotypes, chromosome banding and molecular cytogenetics

Among the understudied tribes, information on chromosome morphology, size and karyotype are reported in very few taxa (Table 2). In Gynostemmapentaphyllum Thunberg, 1784, the number of rDNA loci was suggested to reduce during polyploidization (Pellerin et al. 2018). The Actinostemmatenerum Griffith, 1837, genome contained interstitial telomeric repeats which were suggested to be the result of chromosome fusion from ancestral genome. The co-localization of 45S and 5S rDNA loci in A.tenerum and Thladianthadubia Bunge, 1833, have been thought to imply regional synteny and shared ancestral traits (Xie et al. 2019b). In the tribe Cucurbiteae, detailed karyotype analysis is known only in Cucurbitamoschata Duchesne, 1786 and C.pepo Linnaeus, 1753, showing conserved 45S and 5S rDNA signals (non-co-localized) in independent analyses (Table 8).

Karyotypes and chromosome sizes are reported in ten species of Momordiceae (Table 3). Interspecific differences have been observed and found to correlate with phylogenetic relationship within Momordica (Ghosh et al. 2021). Infraspecific delimitation of Indian M.charantia varieties was based on fluorochrome banding pattern and genome size divergence (Table 3), corresponding to infraspecific distinction reported in the Japanese bitter gourd cultivars (Kido et al. 2016). FISH in three Momordica species revealed 45S and 5S rDNA sites to be localised on different chromosomes (Table 3). In context of the genome sequence of bitter gourds (Matsumura et al. 2020), further scopes for cytogenetic and genomic investigation remain open.

Karyotype and chromosome size is reported in eight 8 species of Sicyoeae (Table 5). Fluorochrome banding pattern has facilitated comparative analysis in Luffa species occurring in India (Tables 1, 5) (Bhowmick and Jha 2015a, 2021). The cultivated ridged gourd (L.acutangula Linnaeus, 1753) showed three CMA⁺ satellite bearing pairs (Fig. 1A–C, J) as in the wild L.echinata Roxburgh, 1814 (Fig. 1G–I, L), while the sponge gourd (L.aegyptiaca Miller, 1768 has two satellited pairs (Fig. 1D–F, K). Luffaacutangula and L.echinata also showed up distal DAPI bands (Fig. 1J, L), absent in L.aegyptiaca (Fig. 1K). Trichosanthes species (2n = 22) have inter-specific differences (Fig. 2) as well as infraspecific distinction (T.cucumerina Linnaeus, 1753) in fluorochrome banding pattern (Tables 1, 5, Fig. 2A–H). The male and female plants of T.dioica show similar chromosome number, morphology and genome size but show differences in fluorochrome banding pattern (Fig. 2I–P, Table 5). The 11^th, 12^th and 13^th pairs (CMA⁺) are marker chromosomes in Luffa (Fig. 1, Table 1) while the 10^th and 11^th pairs are conserved CMA⁺ satellited pairs in Trichosanthes (Fig. 2, Table 1). Eight species of Sicyoeae have been subjected to FISH (Table 5). The polyploid and diploid species have differences in the number of rDNA loci, showing separate localization of the 45S and 5S rDNA signals except Sicyosangulatus Linnaeus, 1753 and Trichosantheskirilowii Maximowicz, 1859 (Table 5).

Figure 2. — Somatic metaphase chromosomes and idiograms of *Trichosanthes* species stained with Giemsa (**A, D, I, L**), DAPI (**C, E, J, M**) and CMA3 (**B, F, K, N**) **A–C***T.cucumerinassp.cucumerina* (2n = 22), **D–F***Trichosanthescucumerinassp.cucumerina* ‘Anguina’ (2n = 22) **I–K***T.dioica* (male, 2n = 22) **L–N***T.dioica* (female, 2n = 22). Arrows indicate satellited chromosomes in Giemsa plates and CMA^+ve signals in **B, F, K, N**. Corresponding somatic idiograms (haploid set) of: GT.cucumerinassp.cucumerinaHTrichosanthescucumerinassp.cucumerina ‘Anguina’ OT.dioica male plant PT.dioica female plant. Blue and golden yellow bands in idiograms indicate DAPI^+ve and CMA^+ve signals, respectively. Scale Bars: 5 µm

Benincaseae generally reveal two distal 45S rDNA loci of which at least one locus is either adjacent to 5S rDNA locus (Table 6) or co-localized in the same chromosome as in most of the Cucumis species (Table 7). Exceptionally, a wild species of Benincasa (B.fistulosa Stocks, 1851) has non-adjacent 45S and 5S signals (Li et al. 2016). GC rich satellites were observed in the 12^th pair of chromosomes showing CMA⁺ bands in cultivated Indian ashgourd (B.hispida) (Fig. 3 A–C, J, Tables 1, 6). Lagenariasiceraria Molina, 1782 and Cucumismelo Linnaeus, 1753 are the other two genera having similarity in rDNA hybridization profile, agreeing with phylogenetic affinity (Li et al. 2016).

Citrulluscolocynthis Linnaeus, 1753 and C.lanatus Thunberg, 1794 may share a common ancestor both having two 45S rDNA loci and one 5S locus. Loss of one 45S rDNA locus has given way to C.rehmii De Winter, 1990 while gain of one 5S rDNA locus has been proposed to lead to C.ecirrhosus Cogniaux, 1888 and C.lanatusvar.citroides Bailey, 1930 (presently C.amarus Schrader, 1836) (Reddy et al. 2013; Li et al. 2016). GISH using C.lanatusvar.citroides genome has revealed divergence from C.lanatusvar.lanatus (Reddy et al. 2013).

The genus Cucumis is the largest in Benincaseae with 65 species of which 39 have been studied (Table 7). Among the Cucumis species with x = 12, co-localization rDNA loci (45S and 5S rDNA) have been documented in 14 species, including C.melo (Table 7). However, the number of 45S sites is generally four, which may be six or eight in some cases (Table 7). rDNA hybridization data strongly corroborated with the ‘fusion’ theory for derivation of x = 7 (C.sativus) from x = 12 (C.melo) (Waminal and Kim 2012) which is substantiated by genomic studies (Li et al. 2011). There are ten pericentromeric/ centromeric 45S and two distal 5S rDNA sites in C.sativus while six 45S rDNA sites were reported in C.sativusvar.hardwickii Royle, 1835 (Koo et al. 2005; Zhang et al. 2012). Comparative chromosome painting (Lou et al. 2014) and GISH (Zhang et al. 2015) proved high colinearity between cucumber and melon. Based on chloroplast and nuclear DNA (ITS) phylogeny, C.melo (melon) has been found to be sister to a clade comprising C.sativus and related genera (Dicaelospermum Clarke, 1879 and Mukia Arnott, 1840) (Renner et al. 2007). rDNA site co-localization was found to coincide with geographical origin of 12 Cucumis species (Zhang et al. 2016). The chromosomal affinity between C.metuliferus Schrader, 1838, C.anguira Linnaeus, 1753, C.zeyheri Sonder, 1862, C.myriocarpus Naudin, 1859 and polyploid C.heptadactylis Naudin, 1859 (dioecious) (Yagi et al. 2015) can be substantiated by their phylogenetic proximity based on chloroplast and nuclear DNA (ITS) sequences (Renner et al. 2007). rDNA distribution of C.metuliferus was also the reason to consider proximity with Citrullusnaudinianus Sonder, 1862, (previously Acanthosicyosnaudinianus Sonder, 1862) (Reddy et al. 2013). Infraspecific differences were documented in Cucumismelo on the basis of 45S- 5S rDNA signals (linked or separated) which also possessed unique centromeric satellites (Setiawan et al. 2018, 2020). Moreover, chromosome painting method elucidated chromosomal rearrangement in some Cucumis species (Lou et al. 2014; Li et al. 2018).

The dramatic evolution of Y chromosome was validated in karyotypes (Fig. 3 D–I, K–L) of Cocciniagrandis (Table 6). The 45S rDNA sites enabled confirmation of NORs in the 8^th and 12^th pair containing distal GC rich CMA⁺ signals in C.grandis (Fig. 3 D–I, K–L, Tables 1, 6). 45S and 5S rDNA hybridization pattern was similar in three other Coccinia species and Diplocyclospalmatus Linnaeus, 1753 (Table 6). The three closely related dioecious species of Coccinia accumulated Y chromosome repeats and displayed sex chromosome turnover (Sousa et al. 2017). Strong centromeric CMA bands (Fig. 3 D–I, K–L, Table 1) were observed in C.grandis except Y chromosome (Fig. 3 I, L), presenting a possibility that CgCent (CL1) is a feature of centromeres of dioecious Coccinia species (Sousa et al. 2017). In addition, non-nucleolar CMA⁺ heterochromatin might be associated with sexual differentiation of autosomes in dioecious C.grandis (Fig. 3) which is also a marker in Trichosanthesdioica (Fig. 2, Table 1), opening good scope for further study.

Distinct 45S rDNA sites are higher in number than 5S rDNA sites in Cucurbitaceae (Fig. 4) (Waminal and Kim 2012). The distal 45S rDNA loci are conserved genomic landmarks (Fig. 4) while 5S rDNA loci are relatively diverse (Fig. 4). Based on the literature reports, some NORs (Type I) included chromosomes showing non-colocalized 45S and 5S rDNA sites in seven species of Benincaseae, one species each from Cucurbiteae and Momordiceae and two species of Sicyoeae. The rearrangement of 45S rDNA site in Cucumissativus, probes for chromosome number reduction which may be a consequence of diploidization. The second type (Type II) shows colocalised 45S and 5S rDNA loci, either adjacent or distant, but always on the same chromosome and found in one species each of Benincaseae, Sicyoeae and Actinostemmateae. The third type (Type III) was characterized by chromosomes with non-colocalized and colocalised 45S and 5S rDNA loci, as in 14 species of Benincaseae and one species each of Sicyoeae and Thladiantheae. The rDNA sites of majority of Cucumis species were of non-adjacent type. Hence, type III NORs in majority of Benincaseae genera advocates conservation of the marker chromosomes having distal NOR (45S rDNA). Gynostemmapentaphyllum and some polyploid Cucumis reveal rDNA loci reduction after polyploidization (Zhang et al. 2016; Pellerin et al. 2018).

Figure 4. — Types of chromosomes bearing the NORs as per available reports of rDNA hybridization in *Cucurbitaceae*. Type I: Chromosomes with only non-colocalised 45S and 5S rDNA sites, Type II: Chromosomes with colocalised 45S and 5S rDNA sites, Type III: Chromosomes with both non- colocalised and colocalised 45S and 5S rDNA sites. See text for explanation.

Correlation between parameters

Chromsome numbers in Cucurbitaceae range from x = 5 to x = 16. The most prevalent number x = 12 (Fig. 5) is considered ancestral (Xie et al. 2019b), followed by x = 11, 13, 14 and 10 (Fig. 5). The present regression analyses for 41 taxa (including 16 Indian taxa) (Table 9) revealed significant linear correlation between 2n and HCL, between ploidy and genome size and between ploidy and HCL (Fig. 6). Therefore, an increase in ploidy/ 2n number is linked with increase in HCL. There was no significant correlation between 2C genome size and chromosome numbers. Cytogenetic parameters may not reflect residual evidence of CCT in Cucurbitraceae at present, as reasoned by Alix et al. (2017).

Figure 5. — The types of different base numbers (x, based on published reports) or possible base numbers (x/n, based on reported haploid counts) in *Cucurbitaceae*. The numbers in brackets beside names of genera signify the number of species whose chromosome counts are reported. The % of genera and species with a particular chromosome number, is indicated at the end arrow (out of a total of 44 genera and 188 species with chromosome counts).

Table 9.

Data on fundamental cytogenetic parameters utilized for statistical analysis.

Species	2n Chromosome no.	Ploidy	2C genome size (pg)	MCL (μm)	HCL (μm)	References
Gynostemmapentaphyllum	66	6	3.62			Zhang et al. (2013), Pellerin et al. (2018)
Zanoniaindica	30	2		1.47	22.12	Lekhak et al. (2018)
Momordicabalsamina	22	2		1.30	14.3#	Bharathi et al. (2011)
Momordicacharantiavar.charantia	22	2	0.72	1.97	21.77	Ghosh et al. (2018)
Momordicacharantiavar.muricata	22	2	1.16	2.19	24.19	Ghosh et al. (2018)
Momordicacochinchinensis	28	2	2.64	2.27	31.86	Ghosh et al. (2021)
Momordicacymbalaria	18	2	3.74	3.75	33.79	Ghosh et al. (2021)
Momordicadioica	56	4	3.36	2.75	77.1	Ghosh et al. (2021)
Momordicasahyadrica	28	2		1.34	18.76	Bharathi et al. (2011)
Momordicasubangulata	56	4	3.06	2.15	60.3	Ghosh et al. (2021)
Luffaacutangula	26	2		2.20	28.63	this study
Luffacylindrica	26	2	1.56	2.98	38.77	Bhowmick and Jha (2015a), this study
Luffaechinata	26	2		3.17	41.26	this study
Trichosanthescucumerina	22	2		3.47	37.855	Bhowmick and Jha (2019), this study
Trichosanthescucumerinasubsp.cucumerina Anguina	22	2		3.43	37.74	Bhowmick and Jha (2019), this study
Trichosanthesdioica Male	22	2	2.27	3.71	40.82	Bhowmick and Jha (2015a), this study
Trichosanthesdioica Female	22	2	2.32	3.71	40.82	Bhowmick and Jha (2015a), this study
Benincasahispida	24	2	1.97	3.17	38.08	Bhowmick and Jha (2015a), this study
Citrulluslanatus	22	2		1.33#	14.67	Waminal et al. (2011)
Cocciniagrandis male	24	2	0.92	1.80	20.32	Bhowmick et al. (2012, 2016), this study
Cocciniagrandis female	24	2	0.73	1.86	19.85	Bhowmick et al. (2012, 2016), this study
Cocciniahirtella	24	2	0.988			Sousa et al. (2017)
Cocciniasessilifolia Male	24	2	0.984			Sousa et al. (2017)
Cocciniasessilifolia Female	24	2	0.998			Sousa et al. (2017)
Cocciniatrilobata	20	2	1.263			Sousa et al. (2017)
Lagenariasiceraria	22	2	0.734	1.79	20.06	Achigan-Dako et al. (2008)
Cucumisafricanus	24	2		2.08	25.045	Yagi et al. (2015)
Cucumisanguriavar.anguria	24	2		2.13	25.6	Yagi et al. (2015)
Cucumisanguriavar.longaculeatus	24	2		2.10	25.195	Yagi et al. (2015)
Cucumisheptadactylus	48	4		2.09	50.225	Yagi et al. (2015)
Cucumismelo	24	2	1.05	1.50	17.8#	Marie and Brown (1993), Hoshi et al. (2013)
Cucumismelovar.inodorus	24	2	0.64			Karimzadeh et al. (2010)
Cucumismyriocarpusvar.leptodermis	24	2		1.93	23.19	Yagi et al. (2015)
Cucumismyriocarpusvar.myriocarpus	48	4		2.25	53.985	Yagi et al. (2015)
Cucumiszeyheri	24	2		2.30	27.56	Yagi et al. (2015)
Cucumissativus	14	2	1.03, 1.77##	2.07#	14.50	Barow and Meister (2003), Marie and Brown (1993), Waminal and Kim (2012)
Cucurbitaargyrosperma	40		0.748			Roy et al. (1991), Sisko et al. (2003)
Cucurbitaecuadorensis	40		0.933			Sisko et al. (2003)
Cucurbitafoetidissima	40		0.686			Sisko et al. (2003)
Cucurbitamoschata	40	2	0.708, 0.97##	1.26#	25.19	Sisko et al. (2003), Barrow and Meister (2003), Waminal et al. (2011)
Cucurbitaokeechobeensisssp.martinezii	40		0.74			Sisko et al. (2003)

Open in a new tab

# calculated from chromosome measurements reported in publications, ## different entries for same taxa were taken from different reports

Figure 6. — Scatter plots of 2n chromosome number and ploidy level (predictor variables) versus 2C genome size, MCL (mean chromosome length) and HCL (total length of haploid chromosome set) in *Cucurbitaceae* taxa. Symbols below plots depict regression analysis parameters; square: adjusted R square, circle: standard error of the estimate, triangle: Pearson Correlation, star: 2-tailed significance of Pearson Correlation. Regular lines indicate significant linear regression and dotted lines indicate not significant linear regress

Future directions

Chromosome number and genome size information in the basal clades (understudied tribes) should be given attention to infer ancient base numbers. The parameters of fundamental and molecular cytogenetics are inevitable for genomic interpretation (Weiss-Schneeweiss and Schneeweiss 2013; Deakin et al. 2019) and hence relevant to spot genetic resources and relationships with wild relatives. The current review is not exhaustive but supersedes the scopes of general web resources and brings an offline resource exclusive for Cucurbitaceae.

Acknowledgements

SJ is thankful to the National Academy of Sciences (NASI, Allahabad, India) for the NASI Senior Scientist Fellowship award. BKB gratefully acknowledges Principal, Scottish Church College, India for continuous support and encouragement in research activities.

Citation

Bhowmick BK, Jha S (2022) A critical review on cytogenetics of Cucurbitaceae with updates on Indian taxa. Comparative Cytogenetics 16(2): 93–125. https://doi.org/10.3897/compcytogen.v16.i2.79033

ORCID

Biplab Kumar Bhowmick https://orcid.org/0000-0001-6029-1098

Sumita Jha https://orcid.org/0000-0002-1375-2768

References

Achigan-Dako EG, Fuchs J, Ahanchede A, Blattner FR. (2008) Flow cytometric analysis in Lagenariasiceraria (Cucurbitaceae) indicates correlation of genome size with usage types and growing elevation. Plant Systematics and Evolution 276: e9. 10.1007/s00606-008-0075-2 [DOI]
Alix K, Gérard PR, Schwarzacher T, Heslop-Harrison JS. (2017) Polyploidy and interspecific hybridization: partners for adaptation, speciation and evolution in plants. Annals of Botany 120: 183–194. 10.1093/aob/mcx079 [DOI] [PMC free article] [PubMed] [Google Scholar]
Anmin L, Luqi H, Shukun C, Jeffrey C. (2011) Flora of China 19. http://www.efloras.org/flora_page.aspx?flora_id=2
Arumuganathan K, Earle ED. (1991) Nuclear DNA content of some important plant species. Plant Molecular Biology Reporter 9: 208–218. 10.1007/BF02672069 [DOI] [Google Scholar]
Barow M, Meister A. (2003) Endopolyploidy in seed plants is differently correlated to systematics, organ, life strategy and genome size. Plant, Cell & Environment 26: 571–584. 10.1046/j.1365-3040.2003.00988.x [DOI] [Google Scholar]
Beevy SS, Kuriachan PH. (1996) Chromosome numbers of south Indian Cucurbitaceae and a note on the cytological evolution in the family. Journal of Cytology and Genetics 31: 65–71. [Google Scholar]
Bellot S, Mitchell TC, Schaefer H. (2020) Phylogenetic informativeness analyses to clarify past diversification processes in Cucurbitaceae. Scientific Reports 10: 1–13. 10.1038/s41598-019-57249-2 [DOI] [PMC free article] [PubMed] [Google Scholar]
Bennett MD, Smith JB, Heslop-Harrison JS. (1982) Nuclear DNA amounts in angiosperms. Proceedings of the Royal Society of London – Series B, Biological Sciences 216: 179–199. 10.1098/rspb.1982.0069 [DOI] [PubMed] [Google Scholar]
Bharathi LK, Munshi AD, Vinod SC, Behera TK, Das AB, John KJ. (2011) Cytotaxonomical analysis of Momordica L. (Cucurbitaceae) species of Indian occurrence. Journal of Genetics 90: 21–30. 10.1007/s12041-011-0026-5 [DOI] [PubMed] [Google Scholar]
Bhowmick BK, Jha S. (2015a) Differential heterochromatin distribution, flow cytometric genome size and meiotic behavior of chromosomes in three Cucurbitaceae species. Scientia Horticulturae 193: 322–329. 10.1016/j.scienta.2015.07.006 [DOI] [Google Scholar]
Bhowmick BK, Jha S. (2015b) Dynamics of sex expression and chromosome diversity in Cucurbitaceae: A story in the making. Journal of Genetics 94: 793–808. 10.1007/s12041-015-0562-5 [DOI] [PubMed] [Google Scholar]
Bhowmick BK, Jha S. (2019) Differences in karyotype and fluorochrome banding patterns among variations of Trichosanthescucumerina with different fruit size. Cytologia 84: 237–245. 10.1508/cytologia.84.237 [DOI] [Google Scholar]
Bhowmick BK, Jha S. (2021) A comparative account of fluorescent banding pattern in the karyotypes of two Indian Luffa species. Cytologia 86: 35–39. 10.1508/cytologia.86.35 [DOI] [Google Scholar]
Bhowmick BK, Jha TB, Jha S. (2012) Chromosome analysis in the dioecious cucurbit Cocciniagrandis (L.) Voigt. Chromosome Science 15: 9–15. [Google Scholar]
Bhowmick BK, Yamamoto M, Jha S. (2016) Chromosomal localization of 45S rDNA, sex specific C values and heterochromatin distribution in Cocciniagrandis (L.) Voigt. Protoplasma 253: 201–209. 10.1007/s00709-015-0797-2 [DOI] [PubMed] [Google Scholar]
Chomicki G, Schaefer H, Renner SS. (2020) Origin and domestication of Cucurbitaceae crops: insights from phylogenies, genomics and archaeology. New Phytologist 226: 1240–1255. 10.1111/nph.16015 [DOI] [PubMed] [Google Scholar]
Darlington CD, Janaki Ammal EK. (1945) Chromosome atlas of cultivated plants. George Allen and Unwin LTD, London.
De Donato M, Cequea H. (1994) A cytogenetic study of six cultivars of the chayote, Sechiumedule Sw. (Cucurbitaceae). Journal of Heredity 85: 238–241. 10.1093/oxfordjournals.jhered.a111444 [DOI] [Google Scholar]
Deakin JE, Potter S, O’Neill R, Ruiz-Herrera A, Cioffi MB, Eldridge MD, Fukui K, Marshall Graves JA, Griffin D, Grutzner F, Kratochvíl L. (2019) Chromosomics: bridging the gap between genomes and chromosomes. Genes 10: e627. 10.3390/genes10080627 [DOI] [PMC free article] [PubMed]
Ghosh I, Bhowmick BK, Jha S. (2018) Cytogenetics of two Indian varieties of Momordicacharantia L. (bittergourd). Scientia Horticulturae 240: 333–343. 10.1016/j.scienta.2018.06.027 [DOI] [Google Scholar]
Ghosh I, Saha PS, Bhowmick BK, Jha S. (2021) A phylogenetic analysis of Momordica (Cucurbitaceae) in India based on karyo-morphology, nuclear DNA content and rDNA ITS1–5.8S–ITS2 sequences. Protoplasma 258: 347–60. 10.1007/s00709-020-01576-z [DOI] [PubMed] [Google Scholar]
Goldblatt P, Lowry PP. (2011) The Index to Plant Chromosome Numbers (IPCN): three decades of publication by the Missouri Botanical Garden come to an end. Annals of the Missouri Botanical Garden 98: 226–227. 10.3417/2011027 [DOI] [Google Scholar]
Guo J, Xu W, Hu Y, Huang J, Zhao Y, Zhang L, Huang CH, Ma H. (2020) Phylotranscriptomics in cucurbitaceae reveal multiple whole-genome duplications and key morphological and molecular innovations. Molecular Plant 13: 1117–1133. 10.1016/j.molp.2020.05.011 [DOI] [PubMed] [Google Scholar]
Han Y, Zhang T, Thammapichai P, Weng Y, Jiang J. (2015) Chromosome-specific painting in Cucumis species using bulked oligonucleotides. Genetics: 200(3): 771–779. 10.1534/genetics.115.177642 [DOI] [PMC free article] [PubMed] [Google Scholar]
Han Y, Zhang Z, Huang S, Jin W. (2011) An integrated molecular cytogenetic map of Cucumissativus L. chromosome 2. BMC Genetics 12: e18. 10.1186/1471-2156-12-18 [DOI] [PMC free article] [PubMed]
Han Y, Zhang Z, Liu C, Liu J, Huang S, Jiang J, Jin W. (2009) Centromere repositioning in cucurbit species: implication of the genomic impact from centromere activation and inactivation. Proceedings of the National Academy of Sciences 106: 14937–14941. 10.1073/pnas.0904833106 [DOI] [PMC free article] [PubMed] [Google Scholar]
Hoshi Y, Kido M, Yagi K, Tagashira N, Morikawa A, Nagano K. (2013) Somatic chromosome differentiation in Cucumismelo L. and C.metuliferus E. Mey. ex Naudin. Chromosome Botany 8: 7–12. 10.3199/iscb.8.7 [DOI] [Google Scholar]
Hoshi Y, Mori M, Matoba H, Tagashira N, Murata T, Plader W, Malepszy S. (2008) Chromosomal polymorphism of two pickling cucumbers (Cucumissativus L.) revealed by fluorescent staining with CMA and DAPI. Cytologia 73: 41–48. 10.1508/cytologia.73.41 [DOI] [Google Scholar]
Jha (2021) Karyotype diversity in cultivated and wild Indian rice through EMA-based chromosome analysis. Journal of Genetics 100: 1–15. 10.1007/s12041-021-01332-z [DOI] [PubMed] [Google Scholar]
Karimzadeh G, Mousavi SH, Jafarkhani-Kermani M, Jalali-Javaran M. (2010) Karyological and nuclear DNA variation in Iranian endemic muskmelon (Cucumismelovar.inodorus). Cytologia 75: 451–461. 10.1017/S147926211400077X [DOI] [Google Scholar]
Kausar N, Yousaf Z, Younas A, Ahmed HS, Rasheed M, Arif A, Rehman HA. (2015) Karyological analysis of bitter gourd (Momordicacharantia L., Cucurbitaceae) from Southeast Asian countries. Plant Genetic Resources 13: 180–182. 10.1017/S147926211400077X [DOI] [Google Scholar]
Kido M, Morikawa A, Saetiew K, Hoshi Y. (2016) A cytogenetic study of three Japanese cultivars of Momordicacharantia L. Cytologia 81: 7–12. 10.1508/cytologia.81.7 [DOI] [Google Scholar]
Koo DH, Hur Y, Jin DC, Bang JW. (2002) Karyotype analysis of a Korean cucumber cultivar (Cucumissativus L. cv. Winter Long) using C-banding and bicolor fluorescence in situ hybridization. Molecules and Cells 13: 413–418. [PubMed] [Google Scholar]
Koo DH, Choi HW, Cho J, Hur Y, Bang JW. (2005) A high-resolution karyotype of cucumber (Cucumissativus L. ‘Winter Long’) revealed by C-banding, pachytene analysis, and RAPD-aided fluorescence in situ hybridization. Genome 48: 534–540. 10.1139/g04-128 [DOI] [PubMed] [Google Scholar]
Kumar V, Subramaniam B. (1987) Chromosome atlas of flowering plants of the Indian subcontinent. Vol 1 and 2. Botanical Survey of India.
Lekhak MM, Yadav PB, Attar UA, Rajput KS, Ghane SG. (2018) Cytopalynological studies in Zanoniaindica (Cucurbitaceae), a monotypic genus. The Nucleus 61: 105–109. 10.1007/s13237-018-0234-y [DOI] [Google Scholar]
Li D, H Cuevas E, Yang L, Li Y, Garcia-Mas J, Zalapa J, J Staub E, Luan F, Reddy U, He X, Gong Z, Weng Y. (2011) Syntenic relationships between cucumber (Cucumissativus L.) and melon (C.melo L.) chromosomes as revealed by comparative genetic mapping. BMC Genomics 12: e396. 10.1186/1471-2164-12-396 [DOI] [PMC free article] [PubMed]
Li K, Wang H, Wang J, Sun J, Li Z, Han Y. (2016) Divergence between C.melo and african Cucumis species identified by chromosome painting and rDNA distribution pattern. Cytogenetic and Genome Research 150: 150–155. 10.1159/000453520 [DOI] [PubMed] [Google Scholar]
Li Q, Ma L, Huang J, Li LJ. (2007) Chromosomal localization of ribosomal DNA Sites and karyotype analysis in three species of Cucurbitaceae. Journal-Wuhan University Natural Sciences Edition 53: e449.
Li Z, Bi Y, Wang X, Wang Y, Yang S, Zhang Z, Chen J, Lou Q. (2018) Chromosome identification in Cucumisanguria revealed by cross-species single-copy gene FISH. Genome 61: 397–404. 10.1139/gen-2017-0235 [DOI] [PubMed] [Google Scholar]
Liu C, Liu J, Li H, Zhang Z, Han Y, Huang S, Jin W. (2010) Karyotyping in melon (Cucumismelo L.) by cross-species fosmid fluorescence in situ hybridization. Cytogenetic and Genome Research 129: 241–249. 10.1159/000314343 [DOI] [PubMed] [Google Scholar]
Lombello RA, Pinto-Maglio CAF. (2007) Cytomolecular Studies in Momordicacharantia L. (Cucurbitaceae), a potential medicinal plant. Cytologia 72: 415–418. 10.1508/cytologia.72.415 [DOI] [Google Scholar]
Lou Q, Zhang Y, He Y, Li J, Jia L, Cheng C, Guan W, Yang S, Chen J. (2014) Single‐copy gene‐based chromosome painting in cucumber and its application for chromosome rearrangement analysis in Cucumis. The Plant Journal 78: 169–179. 10.1111/tpj.12453 [DOI] [PubMed] [Google Scholar]
Lysák MA, Schubert I. (2013) Mechanisms of chromosome rearrangements. In: Greilhuber J, Dolezel J, Wendel JF. (Eds) Plant genome diversity volume 2: Physical structure, behaviour and evolution of plant genomes.Springer, Vienna, 137–147. 10.1007/978-3-7091-1160-4_9 [DOI]
Marie D, Brown SC. (1993) A cytometric exercise in plant DNA histograms, with 2C values for 70 species. Biology of the Cell 78: 41–51. 10.1016/0248-4900(93)90113-S [DOI] [PubMed] [Google Scholar]
Matsumura H, Hsiao MC, Lin YP, Toyoda A, Taniai N, Tarora K, Lee CR. (2020) Long-read bitter gourd (Momordicacharantia) genome and the genomic architecture of nonclassic domestication. Proceedings of the National Academy of Sciences 117: 14543–14551. 10.1073/pnas.1921016117 [DOI] [PMC free article] [PubMed] [Google Scholar]
Mota L, Torices R, Loureiro J. (2016) The evolution of haploid chromosome numbers in the sunflower family. Genome Biology and Evolution 8: 3516–3528. 10.1093/gbe/evw251 [DOI] [PMC free article] [PubMed] [Google Scholar]
Pellerin RJ, Waminal NE, Kim HH. (2018) Triple-color FISH karyotype analysis of four korean wild Cucurbitaceae species. Horticultural Science and Technology 36: 98–107. 10.12972/kjhst.20180011 [DOI] [Google Scholar]
Pellicer J, Leitch IJ. (2020) The Plant DNA C‐values database (release 7.1): an updated online repository of plant genome size data for comparative studies. New Phytologist 226: 301–305. 10.1111/nph.16261 [DOI] [PubMed] [Google Scholar]
Rajkumari K, Joseph John K, Yadav SR, Bhat KV, Rao SR. (2013) Comparative male meiotic studies in some Indian representative species of Cucumis L. (Cucurbitaceae) Caryologia 66: 313–320. 10.1080/00087114.2013.854613 [DOI] [Google Scholar]
Rajkumari K, Joseph John K., Yadav SR, Bhat K V, Shamurailatpam A, Rao SR. (2015) Cytogenetical treatise of Indian representative species of Cucumis. A karyotypic approach. Cytology and Genetics 49: 388–396. 10.3103/S0095452715060079 [DOI] [PubMed] [Google Scholar]
Rayburn AL, Kushad MM, Wannarat W. (2008) Intraspecific genome size variation in pumpkin (Cucurbitapeposubsp.pepo). Horticultural Science 43: 949–951. 10.21273/HORTSCI.43.3.949 [DOI] [Google Scholar]
Ramachandran C, Narayan RKJ. (1985) Chromosomal DNA variation in Cucumis. Theoretical and Applied Genetics 69: 497–502. 10.1007/BF00251092 [DOI] [PubMed] [Google Scholar]
Ramachandran C, Narayan RKJ. (1990) Satellite DNA specific to knob heterochromatin in Cucumismetuliferus (Cucurbitaceae). Genetica 80: 129–138. 10.1007/BF00127133 [DOI] [Google Scholar]
Reddy UK, Aryal N, Islam-Faridi N, Tomason YR, Levi A, Nimmakayala P. (2013) Cytomolecular characterization of rDNA distribution in various Citrullus species using fluorescent in situ hybridization. Genetic Resources and Crop Evolution 60: 2091–2100. 10.1007/s10722-013-9976-1 [DOI] [Google Scholar]
Ren Y, Zhao H, Kou Q, Jiang J, Guo S, Zhang H, Hou W, Zou X, Sun H, Gong G, Levi A, Xu Y. (2012) A high resolution genetic map anchoring scaffolds of the sequenced watermelon genome. PloS ONE 7: e1. 10.1371/journal.pone.0029453 [DOI] [PMC free article] [PubMed]
Renner SS, Schaefer H. (2017) Phylogeny and evolution of the Cucurbitaceae. In: Grumet R, Katzir N, Garcia-Mas J. (Eds) Genetics and genomics of Cucurbitaceae.Springer, Cham, 13–23. 10.1007/7397_2016_14 [DOI]
Renner SS., Schaefer H, Kocyan A. (2007) Phylogenetics of Cucumis (Cucurbitaceae): Cucumber (C.sativus) belongs in an Asian/Australian clade far from melon (C.melo). BMC Evolutionary Biology 7: 1–11. 10.1186/1471-2148-7-1 [DOI] [PMC free article] [PubMed] [Google Scholar]
Renner SS, Sousa A, Chomicki G. (2017) Chromosome numbers, Sudanese wild forms, and classification of the watermelon genus Citrullus, with 50 names allocated to seven biological species. Taxon 66: 1393–1405. 10.12705/666.7 [DOI] [Google Scholar]
Rice A, Glick L, Abadi S, Einhorn M, Kopelman NM, Salman-Minkov A, Mayzel J, Chay O, Mayrose I. (2015) The Chromosome Counts Database (CCDB)–a community resource of plant chromosome numbers. New Phytologist 206: 19–26. 10.1111/nph.13191 [DOI] [PubMed] [Google Scholar]
Roy RP, Saran S, Dutt B. (1991) Cytogenetics of the Cucurbitaceae. In: Tsuchiya T, Gupta PK. (Eds) Chromosome engineering in plants: genetics, breeding, evolution.Part B. Elsevier Science Publishers BV, Amsterdam, The Netherlands, 181–200. 10.1016/B978-0-444-88260-8.50015-X [DOI]
Samuel R, Balasubramaniam S, Morawetz W. (1995) The karyology of some cultivated Cucurbitaceae of Srilanka. Ceylon Journal of Science (Biological Sciences) 24: 17–22. [Google Scholar]
Setiawan AB, Teo CH, Kikuchi S, Sassa H, Kato K, Koba T. (2018) Cytogenetic variation among Cucumis accessions revealed by fluorescence in situ hybridization using ribosomal RNA genes as the probes. Chromosome Science 21: 67–73. [Google Scholar]
Setiawan AB, Teo CH, Kikuchi S, Sassa H, Kato K, Koba T. (2020) Centromeres of Cucumismelo L. comprise Cmcent and two novel repeats, CmSat162 and CmSat189. PloS ONE 15(1): e0227578. 10.1371/journal.pone.0227578 [DOI] [PMC free article] [PubMed]
Soltis DE, Soltis PS, Tate JA. (2004) Advances in the study of polyploidy since plant speciation. New Phytologist 161: 173–191. 10.1046/j.1469-8137.2003.00948.x [DOI] [Google Scholar]
Soltis DE, Visger CJ, Soltis PS. (2014) The polyploidy revolution then and now: Stebbins revisited. American Journal of Botany 101: 1057–1078. 10.3732/ajb.1400178 [DOI] [PubMed] [Google Scholar]
Song K, Kim HH. (2008) Chromosome compositions of four cultivated Cucurbitaceae species. Journal of Life Sciences 18: 1019–1022. 10.5352/JLS.2008.18.7.1019 [DOI] [Google Scholar]
Sousa A, Fuchs J, Renner SS. (2013) Molecular cytogenetics (FISH, GISH) of Cocciniagrandis: A ca. 3 myr-old species of Cucurbitaceae with the largest Y/Autosome divergence in flowering plants. Cytogenetic and Genome Research 139: 107–118. 10.1159/000345370 [DOI] [PubMed] [Google Scholar]
Sousa A, Fuchs J, Renner SS. (2017) Cytogenetic comparison of heteromorphic and homomorphic sex chromosomes in Coccinia (Cucurbitaceae) points to sex chromosome turnover. Chromosome Research 25: 191–200 10.1007/s10577-017-9555-y [DOI] [PubMed] [Google Scholar]
Soza VL, Haworth KL, Di Stilio VS. (2013) Timing and consequences of recurrent polyploidy in meadow-rues (Thalictrum, Ranunculaceae). Molecular Biology and Evolution 30: 1940–1954. 10.1093/molbev/mst101 [DOI] [PubMed] [Google Scholar]
Ting Y, Ya W, Su-qin Z, Guang-dong GENG. (2019) Chromosomal karyotype analysis of Sechiumedule Swartz. Hubei Agricultural Sciences 58: 215.
Uguru MI, Onovo JC. (2011) Evidence of polyploidy in fluted pumpkin (Telfairiaoccidentalis Hook F.). African Journal of Plant Science 5: 287–290. [Google Scholar]
Viruel J, Kantar MB, Gargiulo R, Hesketh-Prichard P, Leong N, Cockel C, Forest F, Gravendeel B, Pérez-Barrales R, Leitch IJ, Wilkin P. (2021) Crop wild phylorelatives (CWPs): Phylogenetic distance, cytogenetic compatibility and breeding system data enable estimation of crop wild relative gene pool classification. Botanical Journal of the Linnean Society 195: 1–33. 10.1093/botlinnean/boaa064 [DOI] [Google Scholar]
Volz SM, Renner SS. (2008) Hybridization, polyploidy and evolutionary transitions between monoecy and dioecy in Bryonia (Cucurbitaceae). American Journal of Botany 95: 1297–1306. 10.3732/ajb.0800187 [DOI] [PubMed] [Google Scholar]
Wang J, Sun P, Li Y, Liu Y, Yang N, Yu J, Ma X, Sun S, Xia R, Liu X, Ge D, Luo S, Liu Y, Kong Y, Cui X, Lei T, Wang L, Wang Z, Ge W, Zhang L, Song X, Yuan M, Guo D, Jin D, Chen W, Pan Y, Liu T, Yang G, Xiao Y, Sun J, Zhang C, Li Z, Xu H, Duan X, Shen S, Zhang Z, Huang S, Wang X. (2018) An overlooked paleotetraploidization in Cucurbitaceae. Molecular Biology and Evolution 35: 16–26. 10.1093/molbev/msx242 [DOI] [PMC free article] [PubMed] [Google Scholar]
Waminal NE, Kim HH. (2012) Dual-color FISH karyotype and rDNA distribution analyses on four Cucurbitaceae species. Horticulture, Environment, and Biotechnology 53: 49–56 . 10.1007/s13580-012-0105-4 [DOI] [Google Scholar]
Waminal NE, Kim HH. (2015) FISH karyotype analysis of four wild cucurbitaceae species using 5S and 45S rDNA probes and the emergence of new polyploids in Trichosantheskirilowii Maxim. Korean Journal of Horticultural Science and Technology 33: 869–876. 10.7235/hort.2015.15101 [DOI] [Google Scholar]
Waminal NE, Kim NS, Kim HH. (2011) Dual‐color FISH karyotype analyses using rDNAs in three Cucurbitaceae species. Genes and Genomics 33: 521–528. 10.1007/s13258-011-0046-9 [DOI] [Google Scholar]
Winterfeld G, Ley A, Hoffmann MH, Paule J, Röser M. (2020) Dysploidy and polyploidy trigger strong variation of chromosome numbers in the prayer-plant family (Marantaceae). Plant Systematics and Evolution 306: 1–7. 10.1007/s00606-020-01663-x [DOI] [Google Scholar]
Whitaker TW. (1950) Polyploidy in Echinocystis. Madrono 10: 209–10. [Google Scholar]
Xie W, Huang J, Ma X. (2019a) Localization of 45S and 5S rDNA sequences on chromosomes of 20 species of Cucurbitaceous plants. Journal of South China Agricultural University 40: 74–81. [Google Scholar]
Xie D, Xu Y, Wang J, Liu W, Zhou Q, Luo S, Huang W, He X, Li Q, Peng Q, Yang X, Yuan J, Yu J, Wang X, Lucas WJ, Huang S, Jiang B, Zhang Z. (2019b) The wax gourd genomes offer insights into the genetic diversity and ancestral cucurbit karyotype. Nature Communications 10: 1–12. 10.1038/s41467-019-13185-3 [DOI] [PMC free article] [PubMed] [Google Scholar]
Xu YH, Yang F, Cheng YL, Ma L, Wang J-B, Li L-J. (2007) Comparative analysis of rDNA distribution in metaphase chromosomes of Cucurbitaceae species. Yi Chuan Hereditas 29(5): 614–620. 10.1360/yc-007-0614 [DOI] [PubMed] [Google Scholar]
Yadava KS, Singh AK, Arya HC. (1984) Cytogenetic investigation in Cucumis L. I. Meiotic analysis in twenty four Cucumis species. Cytologia 49: 1–9. 10.1508/cytologia.49.1 [DOI] [Google Scholar]
Yagi K, Siedlecka E, Pawełkowicz M, Wojcieszek M, Przybecki Z, Tagashira N, Hoshi Y, Malepszy S, Pląder W. (2014) Karyotype analysis and chromosomal distribution of repetitive DNA sequences of Cucumismetuliferus using fluorescence in situ hybridization. Cytogenetic and Genome Research 144: 237–242. 10.1159/000369183 [DOI] [PubMed] [Google Scholar]
Yagi K, Pawełkowicz M, Osipowski P, Siedlecka E, Przybecki Z, Tagashira N, Hoshi Y, Malepszy S, Pląder W. (2015) Molecular cytogenetic analysis of Cucumis wild species distributed in southern Africa: physical mapping of 5S and 45S rDNA with DAPI. Cytogenetic and Genome Research 146: 80–87. 10.1159/000433572 [DOI] [PubMed] [Google Scholar]
Yang L, Koo D-H, Li Y, Zhang X, Luan F, Havey MJ, Jiang J, Weng Y. (2012) Chromosome rearrangements during domestication of cucumber as revealed by high-density genetic mapping and draft genome assembly. The Plant Journal 71: 895–906. 10.1111/j.1365-313X.2012.05017.x [DOI] [PubMed] [Google Scholar]
Zhang L, Cao B, Bai C. (2013) New reports of nuclear DNA content for 66 traditional Chinese medicinal plant taxa in China. Caryologia 66: 375–383. 10.1080/00087114.2013.859443 [DOI] [Google Scholar]
Zhao X, Lu J, Zhang Z, Hu J, Huang S, Jin WW. (2011) Comparison of the distribution of the repetitive DNA sequences in three variants of Cucumissativus reveals their phylogenetic relationships. Journal of Genetics and Genomics 38: 39–45. 10.1016/j.jcg.2010.12.005 [DOI] [PubMed] [Google Scholar]
Zhang C, Kikuchi S, Koba T. (2012) Karyotype comparison of Indian and Japanese cucumber cultivars by fluorescence in situ hybridization probed with tandem repeat sequences. Chromosome Science 15: 17–21. [Google Scholar]
Zhang Y, Chen J, Yi H, Feng J, Wu M. (2005) Staining and slide-preparing technique of mitotic chromosomes and its use in karyotype determination of Cucumismelo L. Acta Botanica Boreali-Occidentalia Sinica 25: 1735–1739. [Google Scholar]
Zhang Y, Cheng C, Li J, Yang S, Wang Y, Li Z, Chen J, Lou Q. (2015) Chromosomal structures and repetitive sequences divergence in Cucumis species revealed by comparative cytogenetic mapping. BMC Genomics 16: 1–3. 10.1186/s12864-015-1877-6 [DOI] [PMC free article] [PubMed] [Google Scholar]
Zheng Y, Wu S, Bai Y, Sun H, Jiao C, Guo S, Zhao K, Blanca J, Zhang Z, Huang S, Xu Y, Weng Y, Mazourek M, Reddy UK, Ando K, McCreight JD, Schaffer AA, Burger J, Tadmor Y, Katzir N, Tang X, Liu Y, Giovannoni JJ, Kai-Ling S, Wechter WP, Levi A, Garcia-Mas J, Grumet R, Fei Z. (2019) Cucurbit Genomics Database (CuGenDB): a central portal for comparative and functional genomics of cucurbit crops. Nucleic Acids Research 47(D1): D1128–D1136. 10.1093/nar/gky944 [DOI] [PMC free article] [PubMed]
Zhang Z-T, Yang S-Q, Li Z-A, Zhang Y-X, Wang Y-Z, Cheng C-Y, J Li, Chen J-F, Lou Q-F. (2016) Comparative chromosomal localization of 45S and 5S rDNAs and implications for genome evolution in Cucumis. Genome 59: 449–457. 10.1139/gen-2015-0207 [DOI] [PubMed] [Google Scholar]

[B1] Achigan-Dako EG, Fuchs J, Ahanchede A, Blattner FR. (2008) Flow cytometric analysis in Lagenariasiceraria (Cucurbitaceae) indicates correlation of genome size with usage types and growing elevation. Plant Systematics and Evolution 276: e9. 10.1007/s00606-008-0075-2 [DOI]

[B2] Alix K, Gérard PR, Schwarzacher T, Heslop-Harrison JS. (2017) Polyploidy and interspecific hybridization: partners for adaptation, speciation and evolution in plants. Annals of Botany 120: 183–194. 10.1093/aob/mcx079 [DOI] [PMC free article] [PubMed] [Google Scholar]

[B3] Anmin L, Luqi H, Shukun C, Jeffrey C. (2011) Flora of China 19. http://www.efloras.org/flora_page.aspx?flora_id=2

[B4] Arumuganathan K, Earle ED. (1991) Nuclear DNA content of some important plant species. Plant Molecular Biology Reporter 9: 208–218. 10.1007/BF02672069 [DOI] [Google Scholar]

[B5] Barow M, Meister A. (2003) Endopolyploidy in seed plants is differently correlated to systematics, organ, life strategy and genome size. Plant, Cell & Environment 26: 571–584. 10.1046/j.1365-3040.2003.00988.x [DOI] [Google Scholar]

[B6] Beevy SS, Kuriachan PH. (1996) Chromosome numbers of south Indian Cucurbitaceae and a note on the cytological evolution in the family. Journal of Cytology and Genetics 31: 65–71. [Google Scholar]

[B7] Bellot S, Mitchell TC, Schaefer H. (2020) Phylogenetic informativeness analyses to clarify past diversification processes in Cucurbitaceae. Scientific Reports 10: 1–13. 10.1038/s41598-019-57249-2 [DOI] [PMC free article] [PubMed] [Google Scholar]

[B8] Bennett MD, Smith JB, Heslop-Harrison JS. (1982) Nuclear DNA amounts in angiosperms. Proceedings of the Royal Society of London – Series B, Biological Sciences 216: 179–199. 10.1098/rspb.1982.0069 [DOI] [PubMed] [Google Scholar]

[B9] Bharathi LK, Munshi AD, Vinod SC, Behera TK, Das AB, John KJ. (2011) Cytotaxonomical analysis of Momordica L. (Cucurbitaceae) species of Indian occurrence. Journal of Genetics 90: 21–30. 10.1007/s12041-011-0026-5 [DOI] [PubMed] [Google Scholar]

[B10] Bhowmick BK, Jha S. (2015a) Differential heterochromatin distribution, flow cytometric genome size and meiotic behavior of chromosomes in three Cucurbitaceae species. Scientia Horticulturae 193: 322–329. 10.1016/j.scienta.2015.07.006 [DOI] [Google Scholar]

[B11] Bhowmick BK, Jha S. (2015b) Dynamics of sex expression and chromosome diversity in Cucurbitaceae: A story in the making. Journal of Genetics 94: 793–808. 10.1007/s12041-015-0562-5 [DOI] [PubMed] [Google Scholar]

[B12] Bhowmick BK, Jha S. (2019) Differences in karyotype and fluorochrome banding patterns among variations of Trichosanthescucumerina with different fruit size. Cytologia 84: 237–245. 10.1508/cytologia.84.237 [DOI] [Google Scholar]

[B13] Bhowmick BK, Jha S. (2021) A comparative account of fluorescent banding pattern in the karyotypes of two Indian Luffa species. Cytologia 86: 35–39. 10.1508/cytologia.86.35 [DOI] [Google Scholar]

[B14] Bhowmick BK, Jha TB, Jha S. (2012) Chromosome analysis in the dioecious cucurbit Cocciniagrandis (L.) Voigt. Chromosome Science 15: 9–15. [Google Scholar]

[B15] Bhowmick BK, Yamamoto M, Jha S. (2016) Chromosomal localization of 45S rDNA, sex specific C values and heterochromatin distribution in Cocciniagrandis (L.) Voigt. Protoplasma 253: 201–209. 10.1007/s00709-015-0797-2 [DOI] [PubMed] [Google Scholar]

[B16] Chomicki G, Schaefer H, Renner SS. (2020) Origin and domestication of Cucurbitaceae crops: insights from phylogenies, genomics and archaeology. New Phytologist 226: 1240–1255. 10.1111/nph.16015 [DOI] [PubMed] [Google Scholar]

[B17] Darlington CD, Janaki Ammal EK. (1945) Chromosome atlas of cultivated plants. George Allen and Unwin LTD, London.

[B18] De Donato M, Cequea H. (1994) A cytogenetic study of six cultivars of the chayote, Sechiumedule Sw. (Cucurbitaceae). Journal of Heredity 85: 238–241. 10.1093/oxfordjournals.jhered.a111444 [DOI] [Google Scholar]

[B19] Deakin JE, Potter S, O’Neill R, Ruiz-Herrera A, Cioffi MB, Eldridge MD, Fukui K, Marshall Graves JA, Griffin D, Grutzner F, Kratochvíl L. (2019) Chromosomics: bridging the gap between genomes and chromosomes. Genes 10: e627. 10.3390/genes10080627 [DOI] [PMC free article] [PubMed]

[B20] Ghosh I, Bhowmick BK, Jha S. (2018) Cytogenetics of two Indian varieties of Momordicacharantia L. (bittergourd). Scientia Horticulturae 240: 333–343. 10.1016/j.scienta.2018.06.027 [DOI] [Google Scholar]

[B21] Ghosh I, Saha PS, Bhowmick BK, Jha S. (2021) A phylogenetic analysis of Momordica (Cucurbitaceae) in India based on karyo-morphology, nuclear DNA content and rDNA ITS1–5.8S–ITS2 sequences. Protoplasma 258: 347–60. 10.1007/s00709-020-01576-z [DOI] [PubMed] [Google Scholar]

[B22] Goldblatt P, Lowry PP. (2011) The Index to Plant Chromosome Numbers (IPCN): three decades of publication by the Missouri Botanical Garden come to an end. Annals of the Missouri Botanical Garden 98: 226–227. 10.3417/2011027 [DOI] [Google Scholar]

[B23] Guo J, Xu W, Hu Y, Huang J, Zhao Y, Zhang L, Huang CH, Ma H. (2020) Phylotranscriptomics in cucurbitaceae reveal multiple whole-genome duplications and key morphological and molecular innovations. Molecular Plant 13: 1117–1133. 10.1016/j.molp.2020.05.011 [DOI] [PubMed] [Google Scholar]

[B24] Han Y, Zhang T, Thammapichai P, Weng Y, Jiang J. (2015) Chromosome-specific painting in Cucumis species using bulked oligonucleotides. Genetics: 200(3): 771–779. 10.1534/genetics.115.177642 [DOI] [PMC free article] [PubMed] [Google Scholar]

[B25] Han Y, Zhang Z, Huang S, Jin W. (2011) An integrated molecular cytogenetic map of Cucumissativus L. chromosome 2. BMC Genetics 12: e18. 10.1186/1471-2156-12-18 [DOI] [PMC free article] [PubMed]

[B26] Han Y, Zhang Z, Liu C, Liu J, Huang S, Jiang J, Jin W. (2009) Centromere repositioning in cucurbit species: implication of the genomic impact from centromere activation and inactivation. Proceedings of the National Academy of Sciences 106: 14937–14941. 10.1073/pnas.0904833106 [DOI] [PMC free article] [PubMed] [Google Scholar]

[B27] Hoshi Y, Kido M, Yagi K, Tagashira N, Morikawa A, Nagano K. (2013) Somatic chromosome differentiation in Cucumismelo L. and C.metuliferus E. Mey. ex Naudin. Chromosome Botany 8: 7–12. 10.3199/iscb.8.7 [DOI] [Google Scholar]

[B28] Hoshi Y, Mori M, Matoba H, Tagashira N, Murata T, Plader W, Malepszy S. (2008) Chromosomal polymorphism of two pickling cucumbers (Cucumissativus L.) revealed by fluorescent staining with CMA and DAPI. Cytologia 73: 41–48. 10.1508/cytologia.73.41 [DOI] [Google Scholar]

[B29] Jha (2021) Karyotype diversity in cultivated and wild Indian rice through EMA-based chromosome analysis. Journal of Genetics 100: 1–15. 10.1007/s12041-021-01332-z [DOI] [PubMed] [Google Scholar]

[B30] Karimzadeh G, Mousavi SH, Jafarkhani-Kermani M, Jalali-Javaran M. (2010) Karyological and nuclear DNA variation in Iranian endemic muskmelon (Cucumismelovar.inodorus). Cytologia 75: 451–461. 10.1017/S147926211400077X [DOI] [Google Scholar]

[B31] Kausar N, Yousaf Z, Younas A, Ahmed HS, Rasheed M, Arif A, Rehman HA. (2015) Karyological analysis of bitter gourd (Momordicacharantia L., Cucurbitaceae) from Southeast Asian countries. Plant Genetic Resources 13: 180–182. 10.1017/S147926211400077X [DOI] [Google Scholar]

[B32] Kido M, Morikawa A, Saetiew K, Hoshi Y. (2016) A cytogenetic study of three Japanese cultivars of Momordicacharantia L. Cytologia 81: 7–12. 10.1508/cytologia.81.7 [DOI] [Google Scholar]

[B33] Koo DH, Hur Y, Jin DC, Bang JW. (2002) Karyotype analysis of a Korean cucumber cultivar (Cucumissativus L. cv. Winter Long) using C-banding and bicolor fluorescence in situ hybridization. Molecules and Cells 13: 413–418. [PubMed] [Google Scholar]

[B34] Koo DH, Choi HW, Cho J, Hur Y, Bang JW. (2005) A high-resolution karyotype of cucumber (Cucumissativus L. ‘Winter Long’) revealed by C-banding, pachytene analysis, and RAPD-aided fluorescence in situ hybridization. Genome 48: 534–540. 10.1139/g04-128 [DOI] [PubMed] [Google Scholar]

[B35] Kumar V, Subramaniam B. (1987) Chromosome atlas of flowering plants of the Indian subcontinent. Vol 1 and 2. Botanical Survey of India.

[B36] Lekhak MM, Yadav PB, Attar UA, Rajput KS, Ghane SG. (2018) Cytopalynological studies in Zanoniaindica (Cucurbitaceae), a monotypic genus. The Nucleus 61: 105–109. 10.1007/s13237-018-0234-y [DOI] [Google Scholar]

[B37] Li D, H Cuevas E, Yang L, Li Y, Garcia-Mas J, Zalapa J, J Staub E, Luan F, Reddy U, He X, Gong Z, Weng Y. (2011) Syntenic relationships between cucumber (Cucumissativus L.) and melon (C.melo L.) chromosomes as revealed by comparative genetic mapping. BMC Genomics 12: e396. 10.1186/1471-2164-12-396 [DOI] [PMC free article] [PubMed]

[B38] Li K, Wang H, Wang J, Sun J, Li Z, Han Y. (2016) Divergence between C.melo and african Cucumis species identified by chromosome painting and rDNA distribution pattern. Cytogenetic and Genome Research 150: 150–155. 10.1159/000453520 [DOI] [PubMed] [Google Scholar]

[B39] Li Q, Ma L, Huang J, Li LJ. (2007) Chromosomal localization of ribosomal DNA Sites and karyotype analysis in three species of Cucurbitaceae. Journal-Wuhan University Natural Sciences Edition 53: e449.

[B40] Li Z, Bi Y, Wang X, Wang Y, Yang S, Zhang Z, Chen J, Lou Q. (2018) Chromosome identification in Cucumisanguria revealed by cross-species single-copy gene FISH. Genome 61: 397–404. 10.1139/gen-2017-0235 [DOI] [PubMed] [Google Scholar]

[B41] Liu C, Liu J, Li H, Zhang Z, Han Y, Huang S, Jin W. (2010) Karyotyping in melon (Cucumismelo L.) by cross-species fosmid fluorescence in situ hybridization. Cytogenetic and Genome Research 129: 241–249. 10.1159/000314343 [DOI] [PubMed] [Google Scholar]

[B42] Lombello RA, Pinto-Maglio CAF. (2007) Cytomolecular Studies in Momordicacharantia L. (Cucurbitaceae), a potential medicinal plant. Cytologia 72: 415–418. 10.1508/cytologia.72.415 [DOI] [Google Scholar]

[B43] Lou Q, Zhang Y, He Y, Li J, Jia L, Cheng C, Guan W, Yang S, Chen J. (2014) Single‐copy gene‐based chromosome painting in cucumber and its application for chromosome rearrangement analysis in Cucumis. The Plant Journal 78: 169–179. 10.1111/tpj.12453 [DOI] [PubMed] [Google Scholar]

[B44] Lysák MA, Schubert I. (2013) Mechanisms of chromosome rearrangements. In: Greilhuber J, Dolezel J, Wendel JF. (Eds) Plant genome diversity volume 2: Physical structure, behaviour and evolution of plant genomes.Springer, Vienna, 137–147. 10.1007/978-3-7091-1160-4_9 [DOI]

[B45] Marie D, Brown SC. (1993) A cytometric exercise in plant DNA histograms, with 2C values for 70 species. Biology of the Cell 78: 41–51. 10.1016/0248-4900(93)90113-S [DOI] [PubMed] [Google Scholar]

[B46] Matsumura H, Hsiao MC, Lin YP, Toyoda A, Taniai N, Tarora K, Lee CR. (2020) Long-read bitter gourd (Momordicacharantia) genome and the genomic architecture of nonclassic domestication. Proceedings of the National Academy of Sciences 117: 14543–14551. 10.1073/pnas.1921016117 [DOI] [PMC free article] [PubMed] [Google Scholar]

[B47] Mota L, Torices R, Loureiro J. (2016) The evolution of haploid chromosome numbers in the sunflower family. Genome Biology and Evolution 8: 3516–3528. 10.1093/gbe/evw251 [DOI] [PMC free article] [PubMed] [Google Scholar]

[B48] Pellerin RJ, Waminal NE, Kim HH. (2018) Triple-color FISH karyotype analysis of four korean wild Cucurbitaceae species. Horticultural Science and Technology 36: 98–107. 10.12972/kjhst.20180011 [DOI] [Google Scholar]

[B49] Pellicer J, Leitch IJ. (2020) The Plant DNA C‐values database (release 7.1): an updated online repository of plant genome size data for comparative studies. New Phytologist 226: 301–305. 10.1111/nph.16261 [DOI] [PubMed] [Google Scholar]

[B50] Rajkumari K, Joseph John K, Yadav SR, Bhat KV, Rao SR. (2013) Comparative male meiotic studies in some Indian representative species of Cucumis L. (Cucurbitaceae) Caryologia 66: 313–320. 10.1080/00087114.2013.854613 [DOI] [Google Scholar]

[B51] Rajkumari K, Joseph John K., Yadav SR, Bhat K V, Shamurailatpam A, Rao SR. (2015) Cytogenetical treatise of Indian representative species of Cucumis. A karyotypic approach. Cytology and Genetics 49: 388–396. 10.3103/S0095452715060079 [DOI] [PubMed] [Google Scholar]

[B52] Rayburn AL, Kushad MM, Wannarat W. (2008) Intraspecific genome size variation in pumpkin (Cucurbitapeposubsp.pepo). Horticultural Science 43: 949–951. 10.21273/HORTSCI.43.3.949 [DOI] [Google Scholar]

[B53] Ramachandran C, Narayan RKJ. (1985) Chromosomal DNA variation in Cucumis. Theoretical and Applied Genetics 69: 497–502. 10.1007/BF00251092 [DOI] [PubMed] [Google Scholar]

[B54] Ramachandran C, Narayan RKJ. (1990) Satellite DNA specific to knob heterochromatin in Cucumismetuliferus (Cucurbitaceae). Genetica 80: 129–138. 10.1007/BF00127133 [DOI] [Google Scholar]

[B55] Reddy UK, Aryal N, Islam-Faridi N, Tomason YR, Levi A, Nimmakayala P. (2013) Cytomolecular characterization of rDNA distribution in various Citrullus species using fluorescent in situ hybridization. Genetic Resources and Crop Evolution 60: 2091–2100. 10.1007/s10722-013-9976-1 [DOI] [Google Scholar]

[B56] Ren Y, Zhao H, Kou Q, Jiang J, Guo S, Zhang H, Hou W, Zou X, Sun H, Gong G, Levi A, Xu Y. (2012) A high resolution genetic map anchoring scaffolds of the sequenced watermelon genome. PloS ONE 7: e1. 10.1371/journal.pone.0029453 [DOI] [PMC free article] [PubMed]

[B57] Renner SS, Schaefer H. (2017) Phylogeny and evolution of the Cucurbitaceae. In: Grumet R, Katzir N, Garcia-Mas J. (Eds) Genetics and genomics of Cucurbitaceae.Springer, Cham, 13–23. 10.1007/7397_2016_14 [DOI]

[B58] Renner SS., Schaefer H, Kocyan A. (2007) Phylogenetics of Cucumis (Cucurbitaceae): Cucumber (C.sativus) belongs in an Asian/Australian clade far from melon (C.melo). BMC Evolutionary Biology 7: 1–11. 10.1186/1471-2148-7-1 [DOI] [PMC free article] [PubMed] [Google Scholar]

[B59] Renner SS, Sousa A, Chomicki G. (2017) Chromosome numbers, Sudanese wild forms, and classification of the watermelon genus Citrullus, with 50 names allocated to seven biological species. Taxon 66: 1393–1405. 10.12705/666.7 [DOI] [Google Scholar]

[B60] Rice A, Glick L, Abadi S, Einhorn M, Kopelman NM, Salman-Minkov A, Mayzel J, Chay O, Mayrose I. (2015) The Chromosome Counts Database (CCDB)–a community resource of plant chromosome numbers. New Phytologist 206: 19–26. 10.1111/nph.13191 [DOI] [PubMed] [Google Scholar]

[B61] Roy RP, Saran S, Dutt B. (1991) Cytogenetics of the Cucurbitaceae. In: Tsuchiya T, Gupta PK. (Eds) Chromosome engineering in plants: genetics, breeding, evolution.Part B. Elsevier Science Publishers BV, Amsterdam, The Netherlands, 181–200. 10.1016/B978-0-444-88260-8.50015-X [DOI]

[B62] Samuel R, Balasubramaniam S, Morawetz W. (1995) The karyology of some cultivated Cucurbitaceae of Srilanka. Ceylon Journal of Science (Biological Sciences) 24: 17–22. [Google Scholar]

[B63] Setiawan AB, Teo CH, Kikuchi S, Sassa H, Kato K, Koba T. (2018) Cytogenetic variation among Cucumis accessions revealed by fluorescence in situ hybridization using ribosomal RNA genes as the probes. Chromosome Science 21: 67–73. [Google Scholar]

[B64] Setiawan AB, Teo CH, Kikuchi S, Sassa H, Kato K, Koba T. (2020) Centromeres of Cucumismelo L. comprise Cmcent and two novel repeats, CmSat162 and CmSat189. PloS ONE 15(1): e0227578. 10.1371/journal.pone.0227578 [DOI] [PMC free article] [PubMed]

[B65] Soltis DE, Soltis PS, Tate JA. (2004) Advances in the study of polyploidy since plant speciation. New Phytologist 161: 173–191. 10.1046/j.1469-8137.2003.00948.x [DOI] [Google Scholar]

[B66] Soltis DE, Visger CJ, Soltis PS. (2014) The polyploidy revolution then and now: Stebbins revisited. American Journal of Botany 101: 1057–1078. 10.3732/ajb.1400178 [DOI] [PubMed] [Google Scholar]

[B67] Song K, Kim HH. (2008) Chromosome compositions of four cultivated Cucurbitaceae species. Journal of Life Sciences 18: 1019–1022. 10.5352/JLS.2008.18.7.1019 [DOI] [Google Scholar]

[B68] Sousa A, Fuchs J, Renner SS. (2013) Molecular cytogenetics (FISH, GISH) of Cocciniagrandis: A ca. 3 myr-old species of Cucurbitaceae with the largest Y/Autosome divergence in flowering plants. Cytogenetic and Genome Research 139: 107–118. 10.1159/000345370 [DOI] [PubMed] [Google Scholar]

[B69] Sousa A, Fuchs J, Renner SS. (2017) Cytogenetic comparison of heteromorphic and homomorphic sex chromosomes in Coccinia (Cucurbitaceae) points to sex chromosome turnover. Chromosome Research 25: 191–200 10.1007/s10577-017-9555-y [DOI] [PubMed] [Google Scholar]

[B70] Soza VL, Haworth KL, Di Stilio VS. (2013) Timing and consequences of recurrent polyploidy in meadow-rues (Thalictrum, Ranunculaceae). Molecular Biology and Evolution 30: 1940–1954. 10.1093/molbev/mst101 [DOI] [PubMed] [Google Scholar]

[B71] Ting Y, Ya W, Su-qin Z, Guang-dong GENG. (2019) Chromosomal karyotype analysis of Sechiumedule Swartz. Hubei Agricultural Sciences 58: 215.

[B72] Uguru MI, Onovo JC. (2011) Evidence of polyploidy in fluted pumpkin (Telfairiaoccidentalis Hook F.). African Journal of Plant Science 5: 287–290. [Google Scholar]

[B73] Viruel J, Kantar MB, Gargiulo R, Hesketh-Prichard P, Leong N, Cockel C, Forest F, Gravendeel B, Pérez-Barrales R, Leitch IJ, Wilkin P. (2021) Crop wild phylorelatives (CWPs): Phylogenetic distance, cytogenetic compatibility and breeding system data enable estimation of crop wild relative gene pool classification. Botanical Journal of the Linnean Society 195: 1–33. 10.1093/botlinnean/boaa064 [DOI] [Google Scholar]

[B74] Volz SM, Renner SS. (2008) Hybridization, polyploidy and evolutionary transitions between monoecy and dioecy in Bryonia (Cucurbitaceae). American Journal of Botany 95: 1297–1306. 10.3732/ajb.0800187 [DOI] [PubMed] [Google Scholar]

[B75] Wang J, Sun P, Li Y, Liu Y, Yang N, Yu J, Ma X, Sun S, Xia R, Liu X, Ge D, Luo S, Liu Y, Kong Y, Cui X, Lei T, Wang L, Wang Z, Ge W, Zhang L, Song X, Yuan M, Guo D, Jin D, Chen W, Pan Y, Liu T, Yang G, Xiao Y, Sun J, Zhang C, Li Z, Xu H, Duan X, Shen S, Zhang Z, Huang S, Wang X. (2018) An overlooked paleotetraploidization in Cucurbitaceae. Molecular Biology and Evolution 35: 16–26. 10.1093/molbev/msx242 [DOI] [PMC free article] [PubMed] [Google Scholar]

[B76] Waminal NE, Kim HH. (2012) Dual-color FISH karyotype and rDNA distribution analyses on four Cucurbitaceae species. Horticulture, Environment, and Biotechnology 53: 49–56 . 10.1007/s13580-012-0105-4 [DOI] [Google Scholar]

[B77] Waminal NE, Kim HH. (2015) FISH karyotype analysis of four wild cucurbitaceae species using 5S and 45S rDNA probes and the emergence of new polyploids in Trichosantheskirilowii Maxim. Korean Journal of Horticultural Science and Technology 33: 869–876. 10.7235/hort.2015.15101 [DOI] [Google Scholar]

[B78] Waminal NE, Kim NS, Kim HH. (2011) Dual‐color FISH karyotype analyses using rDNAs in three Cucurbitaceae species. Genes and Genomics 33: 521–528. 10.1007/s13258-011-0046-9 [DOI] [Google Scholar]

[B79] Winterfeld G, Ley A, Hoffmann MH, Paule J, Röser M. (2020) Dysploidy and polyploidy trigger strong variation of chromosome numbers in the prayer-plant family (Marantaceae). Plant Systematics and Evolution 306: 1–7. 10.1007/s00606-020-01663-x [DOI] [Google Scholar]

[B80] Whitaker TW. (1950) Polyploidy in Echinocystis. Madrono 10: 209–10. [Google Scholar]

[B81] Xie W, Huang J, Ma X. (2019a) Localization of 45S and 5S rDNA sequences on chromosomes of 20 species of Cucurbitaceous plants. Journal of South China Agricultural University 40: 74–81. [Google Scholar]

[B82] Xie D, Xu Y, Wang J, Liu W, Zhou Q, Luo S, Huang W, He X, Li Q, Peng Q, Yang X, Yuan J, Yu J, Wang X, Lucas WJ, Huang S, Jiang B, Zhang Z. (2019b) The wax gourd genomes offer insights into the genetic diversity and ancestral cucurbit karyotype. Nature Communications 10: 1–12. 10.1038/s41467-019-13185-3 [DOI] [PMC free article] [PubMed] [Google Scholar]

[B83] Xu YH, Yang F, Cheng YL, Ma L, Wang J-B, Li L-J. (2007) Comparative analysis of rDNA distribution in metaphase chromosomes of Cucurbitaceae species. Yi Chuan Hereditas 29(5): 614–620. 10.1360/yc-007-0614 [DOI] [PubMed] [Google Scholar]

[B84] Yadava KS, Singh AK, Arya HC. (1984) Cytogenetic investigation in Cucumis L. I. Meiotic analysis in twenty four Cucumis species. Cytologia 49: 1–9. 10.1508/cytologia.49.1 [DOI] [Google Scholar]

[B85] Yagi K, Siedlecka E, Pawełkowicz M, Wojcieszek M, Przybecki Z, Tagashira N, Hoshi Y, Malepszy S, Pląder W. (2014) Karyotype analysis and chromosomal distribution of repetitive DNA sequences of Cucumismetuliferus using fluorescence in situ hybridization. Cytogenetic and Genome Research 144: 237–242. 10.1159/000369183 [DOI] [PubMed] [Google Scholar]

[B86] Yagi K, Pawełkowicz M, Osipowski P, Siedlecka E, Przybecki Z, Tagashira N, Hoshi Y, Malepszy S, Pląder W. (2015) Molecular cytogenetic analysis of Cucumis wild species distributed in southern Africa: physical mapping of 5S and 45S rDNA with DAPI. Cytogenetic and Genome Research 146: 80–87. 10.1159/000433572 [DOI] [PubMed] [Google Scholar]

[B87] Yang L, Koo D-H, Li Y, Zhang X, Luan F, Havey MJ, Jiang J, Weng Y. (2012) Chromosome rearrangements during domestication of cucumber as revealed by high-density genetic mapping and draft genome assembly. The Plant Journal 71: 895–906. 10.1111/j.1365-313X.2012.05017.x [DOI] [PubMed] [Google Scholar]

[B88] Zhang L, Cao B, Bai C. (2013) New reports of nuclear DNA content for 66 traditional Chinese medicinal plant taxa in China. Caryologia 66: 375–383. 10.1080/00087114.2013.859443 [DOI] [Google Scholar]

[B89] Zhao X, Lu J, Zhang Z, Hu J, Huang S, Jin WW. (2011) Comparison of the distribution of the repetitive DNA sequences in three variants of Cucumissativus reveals their phylogenetic relationships. Journal of Genetics and Genomics 38: 39–45. 10.1016/j.jcg.2010.12.005 [DOI] [PubMed] [Google Scholar]

[B90] Zhang C, Kikuchi S, Koba T. (2012) Karyotype comparison of Indian and Japanese cucumber cultivars by fluorescence in situ hybridization probed with tandem repeat sequences. Chromosome Science 15: 17–21. [Google Scholar]

[B91] Zhang Y, Chen J, Yi H, Feng J, Wu M. (2005) Staining and slide-preparing technique of mitotic chromosomes and its use in karyotype determination of Cucumismelo L. Acta Botanica Boreali-Occidentalia Sinica 25: 1735–1739. [Google Scholar]

[B92] Zhang Y, Cheng C, Li J, Yang S, Wang Y, Li Z, Chen J, Lou Q. (2015) Chromosomal structures and repetitive sequences divergence in Cucumis species revealed by comparative cytogenetic mapping. BMC Genomics 16: 1–3. 10.1186/s12864-015-1877-6 [DOI] [PMC free article] [PubMed] [Google Scholar]

[B93] Zheng Y, Wu S, Bai Y, Sun H, Jiao C, Guo S, Zhao K, Blanca J, Zhang Z, Huang S, Xu Y, Weng Y, Mazourek M, Reddy UK, Ando K, McCreight JD, Schaffer AA, Burger J, Tadmor Y, Katzir N, Tang X, Liu Y, Giovannoni JJ, Kai-Ling S, Wechter WP, Levi A, Garcia-Mas J, Grumet R, Fei Z. (2019) Cucurbit Genomics Database (CuGenDB): a central portal for comparative and functional genomics of cucurbit crops. Nucleic Acids Research 47(D1): D1128–D1136. 10.1093/nar/gky944 [DOI] [PMC free article] [PubMed]

[B94] Zhang Z-T, Yang S-Q, Li Z-A, Zhang Y-X, Wang Y-Z, Cheng C-Y, J Li, Chen J-F, Lou Q-F. (2016) Comparative chromosomal localization of 45S and 5S rDNAs and implications for genome evolution in Cucumis. Genome 59: 449–457. 10.1139/gen-2015-0207 [DOI] [PubMed] [Google Scholar]

PERMALINK

A critical review on cytogenetics of Cucurbitaceae with updates on Indian taxa

Biplab Kumar Bhowmick

Sumita Jha

Abstract

Introduction