Molecular phylogeny and morphology reveal two new graminicolous species, Curvularia aurantia sp. nov. and C. vidyodayana sp. nov. with new records of Curvularia spp. from Sri Lanka

Abstract

Despite being a small island, Sri Lanka is rich in fungal diversity. Most of the fungi from Sri Lanka have been identified as pathogens of vegetables, fruits, and plantation crops to date. The pleosporalean genus Curvularia (Dothideomycetes) includes phytopathogenic, saprobic, endophytic, and human/animal opportunistic pathogenic fungal species. The majority of the plant-associated Curvularia species are known from poaceous hosts. During the current study, 22 geographical locations of the country were explored and collections were made from 10 different poaceous hosts. Morphology and molecular phylogeny based on three loci, including nuclear internal transcribed spacers 1 and 2 with 5.8S nrDNA (ITS), glyceraldehyde-3-phosphate dehydrogenase (gapdh), and translation elongation factor 1-α (tef1) supported the description of two new species of fungi described herein as C. aurantia sp. nov. and C. vidyodayana sp. nov. Moreover, novel host-fungal association records for C. chiangmaiensis, C. falsilunata, C. lonarensis, C. plantarum, and C. pseudobrachyspora are updated herein. In addition, five species within the genus Curvularia, viz., C. asiatica, C. geniculata, C. lunata, C. muehlenbeckiae, and C. verruculosa represent new records of fungi from Sri Lanka.

Citation: Ferdinandez HS, Manamgoda DS, Udayanga D, Munasinghe MS, Castlebury LA (2023). Molecular phylogeny and morphology reveal two new graminicolous species, Curvularia aurantia sp. nov. and C. vidyodayana sp. nov. with new records of Curvularia spp. from Sri Lanka. Fungal Systematics and Evolution 12: 219–246. doi: 10.3114/fuse.2023.12.11

INTRODUCTION

The genus Curvularia, typified by C. lunata, is a species-rich genus in the family Pleosporaceae (Pleosporales, Dothideomycetes) (Manamgoda et al. 2012b, 2015). It is known that pathogenic species of Curvularia can cause plant diseases such as black kernels, grain molds, leaf blights, seedling blights, leaf spots, and opportunistic human infections (Sivanesan 1987, Manamgoda et al. 2012b, 2015, Madrid et al. 2014). The development of sympodial conidiophores with tretic, terminal, and intercalary conidiogenous cells as well as transversely septate, often curved conidia characterise species of Curvularia morphologically. Asymmetrically swollen intermediate cells control the characteristic curvature of conidia; however, species with straight conidia have also been reported (Sivanesan 1987, Marin-Felix et al. 2017b). The delimitation of species in Curvularia remains ambiguous due to the overlapping morphological characters among closely related taxa. Thus, it is recommended to incorporate molecular data assessments to accurately identify species (Manamgoda et al. 2014, 2015, Tan et al. 2014, 2018, Marin-Felix et al. 2017b, 2020). Members of the genus are associated with a variety of host plants around the world and display varied life modes, including saprophytic, endophytic, and pathogenic lifestyles. Most of the species are known from poaceous hosts (Ellis 1971, Sivanesan 1987, Manamgoda et al. 2014, Tan et al. 2016).

It is widely accepted that Sri Lanka has a variety of ecosystems and only a small portion of the country’s microbial biodiversity has been documented. Only 3 000 species of fungi are currently recognised, despite the estimated 25 000 species of local mycobiota present. There are 404 species of plant pathogenic fungi listed in the most recent checklist on “Plant pathogenic fungi and Oomycota in Sri Lanka” by Adikaram & Yakandawala (2020). According to the United States National Fungus Collections database and previous publications, only 14 species of Curvularia have been reported so far from Sri Lanka including Curvularia alcornii, C. eleusinicola, C. eragrostidis, C. fallax, C. hawaiiensis, C. lunata, C. pallescens, C. panici-maximi, C. plantarum, C. pseudointermedia, C. ravenelii, C. senegalensis, C. simmonsii, and C. tuberculata (Salim & Mahindapala 1981, Sivanesan 1987, Richardson 1990, Adikaram & Yakandawala 2020, Ferdinandez et al. 2021, Farr & Rossman 2022, Jayawardena et al. 2022). Therefore, the objective of this work is to collect Curvularia species from poaceous hosts and identify them using morphological and molecular data.

MATERIALS AND METHODS

Sample collection, isolation, and morphological identification

From 2018 to 2021, numerous field surveys were conducted spanning 22 different geographical locations in Anuradhapura, Galle, Gampaha, Hambantota, Kurunegala, Matale, Monaragala, and Puttalam districts in Sri Lanka. Samples with leaf lesions, infected panicles, grains, and associated dead plant materials were collected from various poaceous hosts and brought to the laboratory for further processing. Single spore isolation (Chomnunti et al. 2011) was followed to obtain pure cultures of emerging fungi and maintained on potato dextrose agar (PDA, HiMedia-India). The colony characters were determined after inoculating cultures in triplicate on three different media: PDA, corn meal agar (CMA, HiMedia-India), and malt extract agar (MEA, Criterion-USA), at 25 °C, with a 12 h light and 12 h dark light regimen. The Rayner (1970) colour chart was used to record colony colours. Digital images of fungal structures were captured using a Carl Zeiss compound light microscope equipped with an AxioCam digital camera and ZEN lite software (Carl Zeiss Microscopy, Thornwood, NY, USA). The statistical data (mean, standard deviation, minimum, and maximum) for each morphological measurement utilised in the morphological descriptions were recorded. The specimens collected were deposited in USJ-H (University of Sri Jayewardenepura Herbarium) and the living fungal cultures are maintained in USJCC (University of Sri Jayewardenepura Culture Collection). Two taxonomic novelties were registered in MycoBank (www.MycoBank.org; Crous et al. 2004).

DNA extraction, PCR, and sequencing

Genomic DNA was extracted from all the isolates following the method described in Ferdinandez et al. (2021). The nuclear ribosomal internal transcribed spacers 1 and 2 with 5.8S nrDNA region (ITS) and translation elongation factor 1-α (tef1) loci were amplified according to the protocols described in Manamgoda et al. (2012b). The glyceraldehyde-3-phosphate dehydrogenase (gapdh) locus was amplified using the PCR conditions mentioned in Ferdinandez et al. (2021). All the amplificatoin reactions were performed using GoTaq® Green Master Mix (Promega-USA) and PCR products were visualised by agarose gel electrophoresis, in a 2 % gel, with a 100 bp DNA ladder (Promega-USA). The amplified products were purified and sequenced at the Sanger DNA sequencing facility provided by Macrogen (Seoul, Korea).

Sequence alignment, phylogenetic analyses, and species recognition

Raw sequences generated for fresh isolates were assembled with BioEdit v. 7.0.5 for MS Windows (Hall 1999). All the available accepted ex-type and reference DNA sequences for the genus based on numerous publications were included and used in the analyses (Table 1). DNA sequence alignments were performed by MAFFT v. 7 using default settings (http://mafft.cbrc.jp/alignment/server/) (Katoh & Standley 2013). Preliminary identifications of the fresh isolates were determined using newly generated ITS, gapdh, and tef1 sequences using NCBI BLAST. Novel species from the current study were further analysed with their respective closely related taxa from pairwise DNA sequence comparisons using the BLAST tool with default settings (Table 2). Phylogenetic reconstructions were performed using both Maximum parsimony (MP) and Maximum likelihood (ML) criteria as described in Ferdinandez et al. (2022). Initially, single-locus trees were generated and compared to visually find out whether the three loci used are congruent with respect to the placement of each species. As no remarkable incongruence was noted, loci were combined in a concatenated alignment. The multi-locus concatenated alignment included 204 strains of Curvularia and other members of Pleosporaceae, i.e., Alternaria alternata, Bipolaris maydis, Pyrenophora poae, Exserohilum turcicum, Johnalcornia aberrans, and Porocercospora seminalis (Marin-Felix et al. 2020, Ferdinandez et al. 2021). The DNA sequence alignments and phylogenetic trees are available in TreeBASE (study S30416). All DNA sequences were submitted to GenBank (Table 1).

Table 1.

GenBank and culture collection accession numbers of Curvularia isolates used in this study. Sequences generated in this study are in bold.

Species	Isolate/Culture Collection 1	Host/Substratum	Country	GenBank accessions			References
				ITS	gapdh	tef1
C. aeria	CBS 294.61T	Air	Brazil	HF934910	HG779148	–	Amaradasa et al. (2014), Madrid et al. (2014)
C. affinis	CBS 154.34T	Unknown	Indonesia	KJ909780	KM230401	KM196566	Manamgoda et al. (2015)
C. ahvazensis	CBS 144673T	Zinnia elegans	Iran	KX139029	MG428693	MG428686	Mehrabi-Koushki et al. (2018)
C. akaii	CBS 318.86T	Unknown	Japan	LT631340	LT715797	–	Hernandez-Restrepo et al. (2018)
C. akaiiensis	BRIP 16080T	Unknown	India	KJ415539	KJ415407	KJ415453	Tan et al. (2014)
C. alcornii	MFLUCC 10-0703T	Zea mays	Thailand	JX256420	JX276433	JX266589	Manamgoda et al. (2012a)
C. americana	UTHSC 08-3414T	Human ankle	USA	HE861833	HF565488	–	da Cunha et al. (2013)
C. andropogonis	CBS 186.49T	Andropogon nardus	Indonesia	LT631354	LT715835	–	Hernandez-Restrepo et al. (2018)
C. angsiewkeeae	BRIP 72449aT	Scleria sp.	Australia	OK638993	OK655929	OK655924	–
C. annelliconidiophori	CGMCC 3.19352T	Saccharum officinarum	China	MN215641	MN264077	MN263935	Raza et al. (2019)
C. arcana	CBS 127224T	Unknown	Unknown	MN688801	MN688828	MN688855	Marin-Felix et al. (2020)
C. asiatica	MFLUCC 10-0711T	Panicum sp.	Thailand	JX256424	JX276436	JX266593	Manamgoda et al. (2012a)
	USJCC–0072	Oryza sativa	Sri Lanka	OQ275214	OQ269625	–	This study
	USJCC–0074	Oryza sativa	Sri Lanka	OQ275215	OQ269626	OQ332408	This study
	USJCC–0075	Oryza sativa	Sri Lanka	OQ275216	OQ269627	–	This study
C. aurantia sp. nov.	USJCC–0096 T	Zea mays	Sri Lanka	OQ275217	OQ269628	OQ332409	This study
C. australiensis	BRIP 12044T	Oryza sativa	Australia	KJ415540	KJ415406	KJ415452	Tan et al. (2014)
C. australis	BRIP 12521T	Sporobolus caroli	Australia	KJ415541	KJ415405	KJ415451	Tan et al. (2014)
C. austriaca	CBS 102694T	Human nasal cavity	Austria	MN688802	MN688829	MN688856	Marin-Felix et al. (2020)
C. bannonii	BRIP 16732T	Jacquemontia tamnifolia	USA	KJ415542	KJ415404	KJ415450	Tan et al. (2014)
C. beasleyi	BRIP 10972T	Chloris gayana	Australia	MH414892	MH433638	MH433654	Tan et al. (2018)
C. beerburrumensis	BRIP 12942T	Eragrostis bahiensis	Australia	MH414895	MH433634	MH433657	Tan et al. (2018)
C. boeremae	IMI 164633T	Portulaca oleracea	India	MH414911	MH433641	–	Tan et al. (2018)
C. borreriae	CBS 859.73T	Volcanic ash soil	Chile	LT631355	LT715838	–	Hernandez-Restrepo et al. (2018)
C. bothriochloae	BRIP 12522T	Bothriochloa bladhii	Australia	KJ415543	KJ415403	KJ415449	Tan et al. (2014)
C. brachyspora	CBS 186.50T	Soil	Java	HG778983	KM061784	KM230405	Madrid et al. (2014), Manamgoda et al. (2014)
C. buchloes	CBS 246.49T	Buchloe dactyloides	USA	KJ909765	KM061789	KM196588	Manamgoda et al. (2014)
C. cactivora	CBS 580.74R	Member of Cactaceae	Republic of Suriname	MN688803	MN688830	MN688857	Marin-Felix et al. (2020)
C. canadensis	CBS 109239T	Overwintered grass	Canada	MN688804	MN688831	MN688858	Marin-Felix et al. (2020)
C. caricae-papayae	CBS 135941T	Carica papaya	India	LT631350	LT715816	–	Hernandez-Restrepo et al. (2018)
C. chiangmaiensis	CPC 28829T	Zea mays	Thailand	MF490814	MF490836	MF490857	Marin-Felix et al. (2017b)
	USJCC–0022	Panicum virgatum	Sri Lanka	MT410574	MZ971270	MZ971256	This study
	USJCC–0064	Pennisetum pedicellatum	Sri Lanka	MZ948818	MZ971264	–	This study
	USJCC–0069	Cyperus rotundus	Sri Lanka	OQ275218	OQ269629	–	This study
	USJCC–0070	Oryza sativa	Sri Lanka	OQ275219	OQ269630	OQ332410	This study
	USJCC–0087	Panicum virgatum	Sri Lanka	OQ275220	OQ269631	–	This study
	USJCC–0144	Ischaemum sp.	Sri Lanka	OQ275221	OQ269632	–	This study
C. chlamydospora	UTHSC 07-2764T	Human toenail	USA	HG779021	HG779151	–	Madrid et al. (2014)
C. chonburiensis	MFLUCC 16-0375T	Pandanus sp.	Thailand	MH275055	MH412747	–	Tibpromma et al. (2018)
C. chuasooengiae	BRIP 72482aT	Scleria sp.	Australia	OK638997	OK655933	–	–
C. clavata	BRIP 61680b	Oryza rufipogon	Australia	KU552205	KU552167	KU552159	Khemmuk et al. (2016)
C. coatesiae	BRIP 24261T	Litchi chinensis	Australia	MH414897	MH433636	MH433659	Tan et al. (2018)
C. coicicola	HSAUP 990901	Coicis lacryma-jobi	China	AB453880	–	–	Zhang & Zhang (2004)
C. coicis	CBS 192.29T	Coix lacryma-jobi	Japan	HF934917	HG779130	JN601006	Amaradasa et al. (2014), Madrid et al. (2014)
C. coimbatorensis	SZMC 22225T	Human cornea	India	MN628310	MN628306	MN628302	Kiss et al. (2020)
C. colbranii	BRIP 13066T	Crinum zeylanicum	Australia	MH414898	MH433642	MH433660	Tan et al. (2018)
C. comoriensis	CBS 110673	Unknown	Unknown	LT631357	LT715841	–	Hernandez-Restrepo et al. (2018)
C. crassiseptata	CBS 503.90T	Plant material	Nigeria	LT631310	LT715882	MN688859	Hernandez-Restrepo et al. (2018), Marin-Felix et al. (2020)
C. crustacea	BRIP 13524T	Sporobolus sp.	Indonesia	KJ415544	KJ415402	KJ415448	Tan et al. (2014)
C. curculiginis	YZU 181230R	Curculigo capitulata	China	MK507796	MK507794	MK507795	Liu et al. (2019)
C. cymbopogonis	CBS 419.78T	Yucca sp.	Netherlands	HG778985	HG779129	–	Madrid et al. (2014)
C. dactylocteniicola	CPC 28810T	Dactyloctenium aegyptium	Thailand	MF490815	MF490837	MF490858	Marin-Felix et al. (2017b)
C. dactyloctenii	BRIP 12846T	Dactylocteniumradulans	Australia	KJ415545	KJ415401	KJ415447	Tan et al. (2014)
C. determinata	CGMCC 3.19340T	Saccharum officinarum	China	MN215653	MN264088	MN263947	Raza et al. (2019)
C. deightonii	CBS 537.70T	Sorghum vulgare	Denmark	LT631356	LT715839	–	Hernandez-Restrepo et al. (2018)
C. eleusinicola	USJCC–0005T	Eleusine coracana	Sri Lanka	MT262877	MT393583	MT432925	Ferdinandez et al. (2021)
C. elliptiformis	CGMCC 3.19351T	Saccharum officinarum	China	MN215656	MN264091	MN263950	Raza et al. (2019)
C. ellisii	CBS 193.62T	Air	Pakistan	JN192375	JN600963	JN601007	Manamgoda et al. (2011)
C. eragrostidicola	BRIP 12538T	Eragrostis pilosa	Australia	MH414899	MH433643	MH433661	Tan et al. (2018)
C. eragrostidis	CBS 189.48T	Sorghum	Java	HG778986	HG779154	–	Madrid et al. (2014)
C. falsilunata	CGMCC 3.19329T	Saccharum officinarum	China	MN215660	MN264093	MN263954	Raza et al. (2019)
	USJCC–0053	Zea mays	Sri Lanka	MN044758	MN053041	MN053010	This study
	USJCC–0067	Echinochloa crus-galli	Sri Lanka	MZ948820	MZ971266	–	This study
	USJCC–0140	Panicum maximum	Sri Lanka	OQ275222	OQ269633	–	This study
C. flexuosa	CGMCC 3.19447T	Saccharum officinarum	China	MN215663	MN264096	MN263957	Raza et al. (2019)
C. frankliniae	BRIP 72476aT	Sorghum timorense	Australia	OK638995	OK655931	OK655926	–
C. fraserae	BRIP 64708aT	Bothriochloa insculpta	Australia	OM809867	OM721558	OM714552	Tan et al. (2022)
C. geniculata	CBS 187.50T	Andropogon sorghum	Indonesia	KJ909781	KM083609	KM230410	Manamgoda et al. (2015)
	USJCC–0021	Oryza sativa	Sri Lanka	MT410573	MZ971269	MZ971255	This study
	USJCC–0037	Sorghum sp. (Traditional-Swayanjatha)	Sri Lanka	MZ948816	MZ971262	MZ971252	This study
	USJCC–0039	Zea mays	Sri Lanka	ON514026	ON561896	–	This study
	USJCC–0063	Panicum virgatum	Sri Lanka	MZ948817	MZ971263	–	This study
	USJCC–0073	Saccharum officinarum	Sri Lanka	ON514024	ON561894	–	This study
	USJCC–0084	Ischaemum sp.	Sri Lanka	OQ275223	OQ269634	–	This study
C. gladioli	CBS 210.79	Gladiolus sp.	Romania	LT631345	LT715802	–	Hernandez-Restrepo et al. (2018)
C. graminicola	BRIP 23186aT	Aristida ingrata	Australia	JN192376	JN600964	JN601008	Manamgoda et al. (2012b)
C. guangxiensis	CGMCC 3.19330T	Saccharum officinarum	China	MN215667	MN264100	MN263961	Raza et al. (2019)
C. gudauskasii	DAOM 165085	Unknown	Unknown	AF071338	AF081393	–	–
C. harveyi	BRIP 57412T	Triticum aestivum	Australia	KJ415546	KJ415400	KJ415446	Tan et al. (2014)
C. hawaiiensis	BRIP 11987T	Oryza sativa	USA	KJ415547	KJ415399	KJ415445	Tan et al. (2014)
C. heteropogonicola	BRIP 14579T	Heteropogon contortus	India	KJ415548	KJ415398	KJ415444	Tan et al. (2014)
C. heteropogonis	CBS 284.91T	Heteropogon contortus	Australia	KJ415549	JN600969	JN601013	Tan et al. (2014)
C. hominis	UTHSC 09-464T	Human cornea	USA	HG779011	HG779106	–	Madrid et al. (2014)
C. homomorpha	CBS 156.60T	Air	USA	JN192380	JN600970	JN601014	Manamgoda et al. (2012b)
C. hustoniae	BRIP 72486aT	Heteropogon triticeus	Australia	OK638999	OK655935	OK655928	–
C. inaequalis	CBS 102.42T	Soil	France	KJ922375	KM061787	KM196574	Manamgoda et al. (2014)
C. intermedia	CBS 334.64	Avena versicolor	USA	HG778991	HG779155	–	Madrid et al. (2014)
C. iranica	IRAN 3487CT	Bougainvillea spectabilis	Iran	MT551122	MN266487	MN266490	Safi et al. (2020)
C. ischaemi	CBS 630.82T	Ischaemum indicum	Solomon Islands	HG778992	HG779131	–	Madrid et al. (2014)
C. kenpeggii	BRIP 14530T	Triticum aestivum	Australia	MH414900	MH433644	MH433662	Tan et al. (2018)
C. khuzestanica	CBS 144736T	Atriplex lentiformis	Iran	MH688044	MH688043	–	Song et al. (2019)
C. kusanoi	CBS 137.29T	Eragrostis major	Japan	JN192381	LT715862	KM196592	Manamgoda et al. (2011), Hernandez-Restrepo et al. (2018)
C. lamingtonensis	BRIP 12259T	Microlaena stipoides	Australia	MH414901	MH433645	MH433663	Tan et al. (2018)
C. lolii	CMAA 1785T	Lolium multiflorum	Brazil	MT849336	MT889299	MT881706	Victoria Arellano et al. (2021)
C. lonarensis	CBS 140569T	Lonar lake	India	KT315408	KY007019	–	Sharma et al. (2016)
	USJCC–0082	Saccharum officinarum	Sri Lanka	OQ275224	OQ269635	OQ332411	This study
C. lunata	CBS 730.96T	Human lung biopsy	USA	JX256429	JX276441	JX266596	Manamgoda et al. (2012b)
	USJCC–0023	Panicum virgatum	Sri Lanka	MT410575	MZ971271	MZ971257	This study
	USJCC–0132	Zea mays	Sri Lanka	OQ275225	OQ269636	–	This study
C. lycopersici	Strain 11	Solanum lycopersicum	Egypt	KY883347	KY883345	–	Ismail et al. (2016)
C. manamgodae	CGMCC 3.19446T	Saccharum officinarum	China	MN215677	MN264110	MN263971	Raza et al. (2019)
C. malina	CBS 131274T	Zoysia matrella	USA	JF812154	KP153179	KR493095	Tomaso-Peterson et al. (2016)
C. mebaldsii	BRIP 12900T	Cynodon transvaalensis	Australia	MH414902	MH433647	MH433664	Tan et al. (2018)
C. micrairae	BRIP 17068aT	Micraira subulifolia	Australia	OM421618	OM373204	OM373205	–
C. micropus	CBS 127235T	Paspalum notatum	USA	HE792934	LT715859	–	da Cunha et al. (2012), Hernandez-Restrepo et al. (2018)
C. microspora	GUCC 6272T	Hippeastrum striatum	China	MF139088	MF139106	MF139115	Liang et al. (2018)
C. millisiae	BRIP 71718aT	Cyperus aromaticus	Australia	OK661031	OK636415	OK636413	Tan et al. (2022)
C. miyakei	CBS 197.29T	Eragrostis pilosa	Japan	KJ909770	KM083611	KM196568	Manamgoda et al. (2014)
C. moringae	CPC 38873T	Moringa ovalifolia	Namibia	MW175363	MW173105	–	Crous et al. (2020)
C. mosaddeghii	IRAN 3131CT	Syzygium cumini	Iran	MG846737	MH392155	MH392152	Heidari et al. (2018)
C. muehlenbeckiae	CBS 144.63T	Muehlenbeckia sp.	India	HG779002	HG779108	–	Madrid et al. (2014)
	USJCC–0027	Sorghum sp. (Traditional-Swayanjatha)	Sri Lanka	MZ948813	MZ971259	MZ971250	This study
C. nanningensis	GUCC 11005T	Cymbopogon citratus	China	MH885321	MH980005	MH980011	Zhang et al. (2020)
C. neergaardii	BRIP 12919T	Oryza sativa	Ghana	KJ415550	KJ415397	KJ415443	Tan et al. (2014)
C. neoindica	IMI 129790T	Brassica nigra	India	MH414910	MH433649	MH433667	Tan et al. (2018)
C. nicotiae	BRIP 11983T	Soil	Algeria	KJ415551	KJ415396	KJ415442	Tan et al. (2014)
C. nodosa	CPC 28800T	Digitaria ciliaris	Thailand	MF490816	MF490838	MF490859	Marin-Felix et al. (2017b)
C. nodulosa	CBS 160.58	Eleusine indica	USA	JN601033	JN600975	JN601019	Manamgoda et al. (2015)
C. oryzae	CBS 169.53T	Oryza sativa	Vietnam	KP400650	HG779156	KM196590	Madrid et al. (2014), Manamgoda et al. (2015)
C. oryzae-sativae	CBS 127725T	Oryza sativa	Argentina	MN688808	MN688835	MN688863	Marin-Felix et al. (2020)
C. ovariicola	BRIP 15882	Eragrostis schultzii	Australia	JN192384	JN600976	JN601020	Manamgoda et al. (2012b)
C. pallescens	CBS 156.35T	Air	Indonesia	KJ922380	KM083606	KM196570	Manamgoda et al. (2012b)
C. palmicola	MFLUCC 14-0404T	Acoelorrhaphe wrightii	Thailand	MF621582	–	–	Hyde et al. (2017)
C. pandanicola	MFLUCC 15-0746T	Pandanus sp.	Thailand	MH275056	MH412748	MH412763	Tibpromma et al. (2018)
C. panici	Strain OKI-1	Panicum repens	Japan	AB164703	–	–	Chung & Tsukiboshi (2005)
C. panici-maximi	USJCC–0006T	Panicum maximum	Sri Lanka	MN044757	MN053040	MN053009	Ferdinandez et al. (2021)
C. papendorfii	CBS 308.67T	Acacia karroo	South Africa	KJ909774	KM083617	KM196594	Manamgoda et al. (2014)
C. paraverruculosa	FMR 17656 T	Soil	Mexico	LR736641	LR736646	LR736649	Iturrieta-González et al. (2020)
C. patereae	CBS 198.87T	Triticum durum	Argentina	MN688810	MN688837	MN688864	Marin-Felix et al. (2020)
C. penniseti	CBS 528.70	Unknown	Unknown	MH859833	LT715840	–	Hernandez-Restrepo et al. (2018), Vu et al. (2019)
C. perotidis	CBS 350.90T	Perotis rara	Australia	HG778995	HG779138	KM230407	Madrid et al. (2014), Manamgoda et al. (2014)
C. petersonii	BRIP 14642T	Dactyloctenium aegyptium	Australia	MH414905	MH433650	MH433668	Tan et al. (2018)
C. phaeospara	CGMCC 3.19448T	Saccharum officinarum	China	MN215686	MN264118	MN263980	Raza et al. (2019)
C. pisi	CBS 190.48T	Pisum sativum	Canada	KY905678	KY905690	KY905697	Marin-Felix et al. (2017a)
C. plantarum	CGMCC 3.19342T	Saccharum officinarum	China	MN215688	MN264120	MN263982	Raza et al. (2019)
	USJCC–0033	Oryza sativa	Sri Lanka	OQ275226	OQ269637	–	This study
	USJCC–0054	Zea mays	Sri Lanka	OQ275227	OQ269638	–	This study
	USJCC–0068	Echinochloa crus-galli	Sri Lanka	OQ275228	OQ269639	–	This study
	USJCC–0078	Zea mays	Sri Lanka	OQ275229	OQ269640	–	This study
	USJCC–0091	Zea mays	Sri Lanka	OQ275230	OQ269641	–	This study
	USJCC–0097	Zea mays	Sri Lanka	OQ275231	OQ269642	–	This study
C. platzii	BRIP 27703bT	Cenchrus clandestinum	Australia	MH414906	MH433651	MH433669	Tan et al. (2018)
C. polytrata	CGMCC 3.19338T	Saccharum officinarum	China	MN215691	MN264123	MN263984	Raza et al. (2019)
C. portulacae	BRIP 14541T	Portulaca oleracea	USA	KJ415553	KJ415393	KJ415440	Tan et al. (2014)
C. prasadii	CBS 143.64T	Jasminum sambac	India	KJ922373	KM061785	KM230408	Manamgoda et al. (2014)
C. protuberans	CGMCC 3.19360T	Saccharum officinarum	China	MN215693	MN264125	MN263986	Raza et al. (2019)
C. protuberata	CBS 376.65T	Deschampsia flexuosa	Scotland	KJ922376	KM083605	KM196576	Manamgoda et al. (2014)
C. pseudobrachyspora	CPC 28808T	Eleusine indica	Thailand	MF490819	MF490841	MF490862	Marin-Felix et al. (2017b)
	USJCC–0024	Zea mays	Sri Lanka	MT410576	MZ971272	MZ971258	This study
	USJCC–0085	Panicum virgatum	Sri Lanka	OQ275232	OQ269643	OQ332412	This study
C. pseudoclavata	CBS 539.70T	Oryza sativa	Denmark	MN688817	MN688844	MN688869	Marin-Felix et al. (2020)
C. pseudoellisii	CBS 298.80T	Sorghum bicolor	Sudan	MN688818	MN688845	MN688870	Marin-Felix et al. (2020)
C. pseudointermedia	CBS 553.89T	Soil	Brazil	MN688819	MN688846	MN688871	Marin-Felix et al. (2020)
C. pseudolunata	UTHSC 09-2092T	Human nasal sinus	USA	HE861842	HF565459	–	da Cunha et al. (2013)
C. pseudoprotuberata	CBS 385.69T	Soil	Canada	MN688821	MN688848	MN688873	Marin-Felix et al. (2020)
C. pseudorobusta	UTHSC 08-3458	Human nasal sinus	USA	HE861838	HF565476	–	da Cunha et al. (2013)
C. radici-foliigena	CGMCC 3.19328T	Saccharum officinarum	China	MN215695	MN264127	MN263988	Raza et al. (2019)
C. radicicola	CGMCC 3.19327T	Saccharum officinarum	China	MN215699	MN264131	MN263992	Raza et al. (2019)
C. ravenelii	BRIP 13165T	Sporobolus fertilis	Australia	JN192386	JN600978	JN601024	Manamgoda et al. (2012b)
C. reesii	BRIP 4358T	Air	Australia	MH414907	MH433637	MH433670	Tan et al. (2018)
C. richardiae	BRIP 4371T	Richardia brasiliensis	Australia	KJ415555	KJ415391	KJ415438	Tan et al. (2014)
C. robusta	CBS 624.68T	Dichanthium annulatum	USA	KJ909783	KM083613	KM196577	Manamgoda et al. (2014)
C. rouhanii	CBS 144674T	Syngonium vellozianum	Iran	KX139030	MG428694	MG428687	Mehrabi-Koushki et al. (2018)
C. ryleyi	BRIP 12554T	Sporobolus creber	Australia	KJ415556	KJ415390	KJ415437	Tan et al. (2014)
C. saccharicola	CGMCC 3.19344T	Saccharum officinarum	China	MN215701	MN264133	MN263994	Raza et al. (2019)
C. sacchari-officinarum	CGMCC 3.19331T	Saccharum officinarum	China	MN215705	MN264137	MN263998	Raza et al. (2019)
C. senegalensis	CBS 149.71	Unknown	Nigeria	HG779001	HG779128	–	Madrid et al. (2014)
C. sesuvii	CGMCC 3.9578T	Sesuvium portulacastrum	China	EF175940	–	–	Zhang & Li (2009)
C. shahidchamranensis	SCUA-8-MarunT	Soil	Iran	MH550084	MH550083	–	Dehdari et al. (2018)
C. sichuanensis	Strain BN9	Air	China	MH483998	–	–	Zhang et al. (2007)
C. siddiquii	CBS 196.62T	Air	Pakistan	MN688823	MN688850	–	Marin-Felix et al. (2020)
C. simmonsii	USJCC–0002T	Panicum maximum	Sri Lanka	MN044753	MN053011	MN053005	Ferdinandez et al. (2021)
C. soli	CBS 222.96T	Soil	Papua New Guinea	KY905679	KY905691	KY905698	Marin-Felix et al. (2017a)
C. sorghina	BRIP 15900T	Sorghum bicolor	Australia	KJ415558	KJ415388	KJ415435	Tan et al. (2014)
C. spicifera	CBS 274.52	Soil	Spain	JN192387	JN600979	JN601023	Manamgoda et al. (2012b)
C. sporobolicola	BRIP 23040bT	Sporobolus australasicus	Australia	MH414908	MH433652	MH433671	Tan et al. (2018)
C. stenotaphri	BRIP 71303T	Stenotaphrum secundatum	Australia	MZ681952	MZ695824	MZ695819	Crous et al. (2021b)
C. subpapendorfii	CBS 656.74T	Soil	Egypt	KJ909777	KM061791	KM196585	Manamgoda et al. (2015)
C. suttoniae	FMR 10992T	Human leg wound	USA	HE861828	HF565479	LR736651	Iturrieta-González et al. (2020)
C. tamilnaduensis	SZMC 22226T	Human cornea	India	MN628311	MN628307	MN628303	Kiss et al. (2020)
C. tanzanica	IMI 507176T	Cyperus aromaticus	Tanzania	MW396857	MW388669	–	Crous et al. (2021a)
C. templetoniae	BRIP 72453aT	Hyparrhenia hirta	Australia	OK442370	OK655930	OK655925	–
C. thailandicum	MFLUCC 15-0747T	Pandanus sp.	Thailand	MH275057	MH412749	MH412764	Tibpromma et al. (2018)
C. tribuli	CBS 126975T	Tribulus terrestris	South Africa	MN688825	MN688852	MN688875	Marin-Felix et al. (2020)
C. trifolii	ICMP 6149	Setaria glauca	New Zealand	KM230395	KM083607	JX266600	Manamgoda et al. (2012b, 2015)
C. tripogonis	BRIP 12375T	Tripogon loliiformis	Australia	JN192388	JN600980	JN601025	Manamgoda et al. (2011)
C. tropicalis	BRIP 14834T	Coffea arabica	India	KJ415559	KJ415387	KJ415434	Tan et al. (2014)
C. tsudae	ATCC 44764T	Chloris gayana	Japan	KC424596	KC747745	KC503940	Tan et al. (2018)
C. tuberculata	CBS 146.63T	Zea mays	India	JX256433	JX276445	JX266599	Manamgoda et al. (2012b)
C. umbiliciformis	CGMCC 3.19346T	Saccharum officinarum	China	MN215711	MN264142	MN264004	Raza et al. (2019)
C. uncinata	CBS 221.52T	Oryza sativa	Vietnam	HG779024	HG779134	–	Madrid et al. (2014)
C. variabilis	CPC 28815T	Chloris barbata	Thailand	MF490822	MF490844	MF490865	Marin-Felix et al. (2017b)
C. verruciformis	CBS 537.75	Vanellus miles	New Zealand	HG779026	HG779133	–	Madrid et al. (2014)
C. verrucosa	CBS 422.93	Air	Cuba	MN688826	MN688853	MN688876	Marin-Felix et al. (2020)
C. verruculosa	CBS 150.63	Punica granatum	India	KP400652	KP645346	KP735695	Manamgoda et al. (2015)
	USJCC–0028	Oryza sativa	Sri Lanka	MZ948815	MZ971261	MZ971251	This study
	USJCC–0031	Zea mays	Sri Lanka	MZ948814	MZ971260	–	This study
	USJCC–0103	Saccharum officinarum	Sri Lanka	OQ275233	OQ269644	–	This study
C. vidyodayana sp. nov.	USJCC–0029 T	Oryza sativa	Sri Lanka	OQ275234	OQ269645	OQ332413	This study
	USJCC–0062	Oryza sativa	Sri Lanka	OQ275234	OQ269646	–	This study
C. vietnamensis	FMR 17659T	Unidentified dead leaves	Vietnam	LR736642	LR736644	LR736647	Iturrieta-González et al. (2020)
C. warraberensis	BRIP 14817T	Dactyloctenium aegyptium	Australia	MH414909	MH433653	MH433672	Tan et al. (2018)
C. xishuangbannaensis	KUMCC 17-0185T	Pandanus amaryllifollus	Thailand	MH275058	MH412750	MH412765	Tibpromma et al. (2018)
C. yamadana	COAD 375	Cyperus rotundus	Brazil	MN954704	–	MT008259	Ferreira & Barreto (2020)
Outgroups
Alternaria alternata	CBS 916.96T	Unknown	Unknown	KF465761	–	–	Lecellier et al. (2014)
Bipolaris maydis	CBS 137271/C5T	Zea mays	USA	AF071325	KM034846	KM093794	Berbee et al. (1999), Manamgoda et al. (2014)
Exserohilum turcicum	CBS 690.71T	Zea mays	Germany	LT837487	LT882581	LT896618	Hernandez-Restrepo et al. (2018)
Johnalcornia aberrans	CBS 510.91T	Eragrostis parviflora	Australia	KJ415522	KJ415424	–	Tan et al. (2014)
Porocercospora seminalis	CPC 21305T	Bouteloua dactyloides	USA	HF934942	–	–	Amaradasa et al. (2014)
Pyrenophora poae	BRIP 10953	Member of Poaceae	Australia	KJ415566	KJ415380	KJ415427	Tan et al. (2014)

¹Culture collections: ATCC: American Type Culture Collection, Virginia, USA; BRIP: Queensland Plant Pathology Herbarium, Queensland, Australia; CBS: CBS-KNAW Fungal Biodiversity Centre, Utrecht, The Netherlands; CGMCC: China General Microbiological Culture Collection, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China; CMAA: Collection of Microorganisms of Agricultural and Environmental Importance at Embrapa Environmental research unit (Embrapa Meio-Ambiente), Brazil; COAD: Universidade Federal de Viçosa - Coleção Octávio de Almeida Drumond; CPC: working collection of P.W. Crous, housed at the Westerdijk Fungal Biodiversity Institute, Utrecht, the Netherlands; DAOM: Plant Research Institute, Department of Agriculture (Mycology), Ottawa, Canada; FMR: Medical School of the Rovira i Virgili University, Reus, Spain; GUCC: Department of Plant Pathology, Agriculture College, Guizhou University, P.R. China; HSAUP: Herbarium of Shandong Agricultural University, Department of Plant Pathology, China; ICMP: International Collection of Micro-organisms from Plants, Landcare Research, Auckland, New Zealand; IMI: International Mycological Institute, Kew, UK; IRAN: Iranian Fungal Culture Collection, Iranian Research Institute of Plant Protection, Iran; KUMCC: Kunming Institute of Botany Culture Collection; MFLUCC: Mae Fah Luang University culture collection, Thailand; SCUA: the Collection of Fungal Cultures, Department of Plant Protection, Shahid Chamran University of Ahvaz, Iran; SZMC: Szeged Microbiology Collection, Hungary; YZU: Culture Collection of Yangtze University Jingzhou, China; USJCC: University of Sri Jayewardenepura Culture Collection, Sri Lanka; UTHSC: Fungus Testing Laboratory, University of Texas Health Science Center, San Antonio, Texas. ^R and ^T indicate reference and ex-type strains, respectively.

Table 2.

Pairwise comparison of the loci analysed for novel species described in the current study with closely related taxa.

Novel species	Closely related taxa	Locus, Identity and Gaps (both with percentages)
		ITS		gapdh		tef1
		Identity and percentage	Gaps	Identity and percentage	Gaps	Identity and percentage	Gaps
Curvularia aurantia sp. nov. (USJCC–0096)	C. coicis	551/565 (98 %)	6/565 (1 %)	360/373 (97 %)	0/373 (0 %)	910/914 (99 %)	0/914 (0 %)
	C. ischaemi	452/487 (93 %)	16/487 (3 %)	497/502 (99 %)	0/502 (0 %)	–	–
	C. crassiseptata	455/485 (94 %)	15/485 (3 %)	336/345 (97 %)	1/345 (0 %)	868/891 (97 %)	0/891 (0 %)
	C. comoriensis	453/486 (93 %)	16/486 (3 %)	517/542 (95 %)	6/542 (1 %)	–	–
	C. heteropogonicola	385/405 (95 %)	10/405 (2 %)	355/370 (96 %)	1/370 (0 %)	781/804 (97 %)	0/804 (0 %)
	C. cymbopogonis	454/485 (94 %)	15/485 (3 %)	325/337 (96 %)	1/337 (0 %)	–	–
Curvularia vidyodayana sp. nov. (USJCC–0029)	C. affinis	506/509 (99 %)	1/509 (0 %)	542/551 (98 %)	0/551 (0 %)	898/899 (99 %)	0/899 (0 %)
	C. soli	499/509 (98 %)	5/509 (0 %)	579/587 (99 %)	0/587 (0 %)	918/921 (99 %)	0/921 (0 %)
	C. thailandicum	496/507 (98 %)	6/507 (1 %)	335/347 (97 %)	0/347 (0 %)	901/909 (99 %)	1/909 (0 %)
	C. xishuangbannaensis	493/504 (98 %)	5/504 (0 %)	528/537 (98 %)	1/537 (0 %)	876/883 (99 %)	2/883 (0 %)
	C. millisiae	504/514 (98 %)	5/514 (0 %)	564/576 (98 %)	0/576 (0 %)	972/978 (99 %)	1/978 (0 %)
	C. asiatica	460/467 (99 %)	5/467 (1 %)	483/487 (99 %)	0/487 (0 %)	913/916 (99 %)	0/916 (0 %)
	C. senegalensis	504/514 (98 %)	5/514 (0 %)	536/545 (98 %)	0/545 (0 %)	–	–
	C. geniculata	504/514 (98 %)	5/514 (0 %)	443/448 (99 %)	0/448 (0 %)	821/822 (99 %)	0/822 (0 %)

RESULTS

The concatenated three loci sequence alignment comprised 204 Curvularia strains and six other pleosporalean taxa as out-groups. Out of the number of 204 Curvularia strains in the alignment, 36 in-group strains were fresh isolates collected from the current study. Alignment statistics for the parsimony analysis are as follows: 2 236 total characters, with 1 431 constant characters, 588 parsimony-informative characters, and 217 variable parsimony uninformative characters. Tree statistics for equally most parsimonious tree resulting from the parsimony analysis of the combined dataset with bootstrap 50 % majority rule consensus are as follows: TL = 3 961, CI = 0.327, RI = 0.757, RC = 0.247, HI = 0.673. The resulting phylogram (Fig. 1) from the multi-locus phylogenetic analyses revealed that two lineages from the fresh isolates are distinct from closely related taxa and all other members of the genus, which are described as novel species below (Curvularia aurantia sp. nov. and C. vidyodayana sp. nov). The remaining 33 isolates obtained were identified as C. asiatica, C. chiangmaiensis, C. falsilunata, C. geniculata, C. lonarensis, C. lunata, C. muehlenbeckiae, C. plantarum, C. pseudobrachyspora, and C. verruculosa.

Fig. 1.

Phylogram of Curvularia spp. based on the combined ITS, gapdh, and tef1 alignment. Maximum parsimony and RAxML bootstrap support values above 70 % are shown at the nodes respectively. Type cultures are marked with an asterisk. Novel species from the current study are indicated in red. New records are in bold. The tree is rooted with other members of Pleosporaceae (Alternaria alternata, Bipolaris maydis, Pyrenophora poae, Exserohilum turcicum, Johnalcornia aberrans, and Porocercospora seminalis); the root branches were shortened to facilitate layout by the factor indicated on them.

TAXONOMY

In this section, morphological descriptions, notes on taxonomy, and phylogeny with illustrations are provided for two novel species and 10 other species isolated from Sri Lanka with new host and geographic distribution records.

Curvularia aurantia Ferdinandez, Manamgoda & Udayanga, sp. nov. MycoBank MB 848300. Fig. 2.

Fig. 2.

Curvularia aurantia (USJCC–0096, ex-type). A. Host: lesions on leaf blade of Zea mays. B–D. Seven-day-old colony on PDA, CMA, and MEA, respectively. E. Stroma on 14-d-old colony on PDA. F–I. Conidia. J. Conidiophore. K. Conidiophore with immature conidia. Scale bars: F–I = 6 μm; J, K = 9 μm.

Etymology: Species is named after the latinised term for orange colour “aurantia”; colour of the pigment diffused to PDA.

On leaf lesions (2–5 cm long) of Zea mays. Asexual morph: On CMA hyphae 4–5 μm wide, subhyaline to pale brown, septate, branched. Stroma 3–8 mm long, dark brown to black, elongated, branched, dense hypha. Conidiophores (115–)161–500(–611) × 5–8(–9) μm (x̄ = 330 × 6 μm, n = 20), hyaline to pale brown, micronematous to macronematous, septate, simple or branched, straight or flexuous, sometimes geniculate at the apex. Conidiogenous cells (4–)5–10(–15) × 4–6(–7) μm (x̄ = 8 × 5 μm, n = 20), hyaline to pale brown, smooth-walled, subcylindrical to slightly swollen, terminal or intercalary, mono- to polytretic. Conidia (18–)23–26(–30) × (10–)11–13(–16) μm (x̄ = 24 × 12 μm, n = 30), hyaline to pale brown, curved, asymmetrical, sometimes Y-shaped, enlarged middle cells, 3–4-distoseptate; hila inconspicuous. Microconidiation observed. Sexual morph not observed.

Culture characteristics: Colonies on PDA reaching 36 mm diam after 7 d at 25 °C, colonies from above: irregular, margin irregular, slightly raised, velvety appearance, dark brown at the margin, mouse grey aerial mycelia, producing orange colour pigment which defuse to the media; dark brown to black elongated, branched stroma observed above the media after about 5 d, reverse: dark brown at the margin, black in the centre. Colonies on CMA reaching 40 mm diam after 7 d at 25 °C, colonies from above: circular, margin irregular, flat, hairy appearance, white at the margin, grey in the centre, concentric ring growth; reverse: pale brown centre to margin. Colonies on MEA reaching 50 mm diam after 7 d at 25 °C, colonies from above: circular, margin mostly irregular, flat, hairy appearance, dark green and dark grey concentric ring growth, mouse grey in the centre; reverse: brown at the margin, black in the centre.

Typus: Sri Lanka, Central Province, Matale District, Dambulla, N 7.903257 E 80.670494, on leaf spots of Zea mays, 15 Aug. 2019, H.S. Ferdinandez (holotype USJ-H-087, culture ex-type USJCC–0096).

Known host and distribution: Zea mays in Sri Lanka (this study).

Notes: Based on the phylogenetic analyses and pairwise DNA sequence comparison results (Table 2), C. aurantia (USJCC–0096) is closely related to C. coicis and C. ischaemi. Pairwise DNA sequence comparison revealed that C. aurantia is distinct from its closely related taxa. Curvularia aurantia differs by having smaller conidia compared to those of C. ischaemi (22.5–)24–35(–40) × (11.5–)13–17.5(–18.5) µm and of C. coicis 40–64 × 17–23 µm (Sivanesan 1987). Conidia of C. ischaemi are 3-distoseptate while in C. coicis they are 4–5-distoseptate. Moreover, when compared to C. aurantia both taxa have shorter conidiophores; C. ischaemi up to 375 µm long and C. coicis up to 200 µm long. Curvularia coicis has been reported from several Coix spp. and Zea mays (Farr & Rossman 2022). Curvularia ischaemi has only been reported from Ischaemum spp. (Farr & Rossman 2022). Curvularia aurantia was collected from Zea mays during this study. Therefore, based on molecular data and morphology, C. aurantia is described herein as a new species.

Curvularia vidyodayana Ferdinandez, Manamgoda & Udayanga, sp. nov. MycoBank MB 848301. Fig. 3.

Fig. 3.

Curvularia vidyodayana (USJCC–0029, ex-type). A–C. Seven-day-old colony on PDA, CMA, and MEA, respectively. D. Chlamydospores. E–G. Conidia attached to conidiophores. H, I. Conidia. Scale bars: D, E, G–I = 5 μm; F = 15 μm.

Etymology: Name refers to the Vidyodaya, former name of the University of Sri Jayewardenepura where this research study was carried out.

Saprobic on grains of Oryza sativa. Asexual morph: On CMA hyphae 4–6 μm wide, hyaline, septate, branched. Conidiophores 51–232(–432) × (4–)5–6 μm (x̄ = 142 × 5 μm, n = 20), hyaline to brown, micronematous to macronematous, septate, simple or branched, straight or flexuous, swollen at the apex. Conidiogenous cells (9–)10–16(–20) × (4–)5–6 μm (x̄ = 13 × 5 μm, n = 20), hyaline to pale brown, smooth-walled, subcylindrical to swollen, terminal or intercalary, mono- to polytretic. Conidia (16–)19–25(–27) × (7–)8–10(–11) μm (x̄ = 22 × 9 μm, n = 30), hyaline immature conidia, pale brown to brown mature conidia, slightly curved, mostly ellipsoidal with broadly tapering ends, mostly enlarged third cell from the base, usually 3-, occasionally 4-distoseptate; hila 2–3 µm wide, slightly protruding, darkened. Chlamydospores 10–12 μm diam, dark brown, globose to subglobose or cylindrical, grouped as chain, thick-walled, terminally and intercalary. Sexual morph not observed.

Culture characteristics: Colonies on PDA reaching 41 mm diam after 7 d at 25 °C, colonies from above: circular, margin entire, slightly raised, cottony appearance, pale brown at the margin, mouse grey in the centre, reverse: brown at the margin, black in the centre. Colonies on CMA reaching 68 mm diam after 7 d at 25 °C, colonies from above: circular, margin entire, flat, hairy appearance, white at the margin, pale brown and grey concentric ring growth; reverse: pale brown centre to margin. Colonies on MEA reaching 73 mm diam after 7 d at 25 °C, colonies from above: circular, margin entire, convex, cottony appearance, dark brown at the margin, white to dark green centre to periphery; reverse: brown at the margin, black in the centre.

Typus: Sri Lanka, Southern Province, Galle District, Yakkalamulla, N 6.078573 E 80.373524, on grains of Oryza sativa, 25 Aug. 2018, H.S. Ferdinandez (holotype USJ-H-009, culture ex-type USJCC–0029); ibid. (isotype USJ-H-010, culture USJCC–0062).

Known host and distribution: Oryza sativa in Sri Lanka (this study).

Notes: Based on the phylogenetic analyses and pairwise DNA sequence comparison results (Table 2), C. vidyodayana is closely related to C. affinis. The pairwise DNA sequence comparison revealed that C. vidyodayana is distinct from its closely related taxa. In the comparison of morphological characters with C. affinis, C. vidyodayana has smaller (19–25 µm), 3–4-distoseptate conidia while C. affinis has 27–49 × 8–13 µm, 4–5-distoseptate conidia. Curvularia affinis is a cosmopolitan fungus and has been recorded in Asian countries from several poaceous hosts including Oryza sativa (India, Malaysia, and Taiwan), Pennisetum typhoides (India), Sorghum vulgare (Taiwan) and Zea mays (Malaysia) (Farr & Rossman 2022). Curvularia vidyodayana was recorded on dried grains of Oryza sativa. Because of the disparities among C. affinis and C. vidyodayana, both in morphological and molecular data, we propose C. vidyodayana as a new species.

Curvularia asiatica Manamgoda et al. [as ‘asianensis’], Sydowia 64: 262. 2012. MycoBank MB 545037. Fig. 4.

Fig. 4.

Curvularia asiatica (USJCC–0075). A. Host: black spore masses on dried grains of Oryza sativa. B–D. Seven-day-old colony on PDA, CMA, and MEA, respectively. E. Immature conidia on conidiophore. F. Conidia attached to conidiophore. G–J. Conidia. Scale bars: E–H = 5 μm; I, J = 6 μm.

Saprobic on dried grains Oryza sativa. Asexual morph: On CMA hyphae 3–4 μm wide, hyaline, septate, branched. Conidiophores (99–)131–368(–495) × (4–)6–9(–12) μm (x̄ = 249 × 8 μm, n = 20), pale brown to dark brown, micronematous to macronematous, septate, simple or branched, straight or flexuous, swollen at the apex. Conidiogenous cells (5–)6–8(–9) × (3–)4–6(–7) μm (x̄ = 7 × 5 μm, n = 20), hyaline to pale brown, smooth-walled, swollen, terminal or intercalary, mono- to polytretic. Conidia (16–)20–26(–34) × (7–)9–11(–14) μm (x̄ = 23 × 10 μm, n = 30), hyaline to pale brown apical and basal cells, pale brown to dark brown matured conidia, straight or curved, asymmetrical, sometimes clavate, enlarged middle cells, dark brown septa, 3–4-distoseptate; hila 1–2 μm wide, protruding, darkened. Sexual morph not observed.

Culture characteristics: Colonies on PDA reaching 84 mm diam after 7 d at 25 °C, colonies from above: circular, margin entire, slightly convex, cottony appearance, dark brown at the margin, grey aerial mycelia, concentric ring growth; reverse: dark brown at the margin, black in the centre. Colonies on CMA reaching 90 mm diam after 7 d at 25 °C, colonies from above: circular, margin entire, flat, hairy appearance, white at the margin, pale brown in the centre, concentric ring growth; reverse: pale brown at the margin, dark brown in the centre. Colonies on MEA reaching 86 mm diam after 7 d at 25 °C, colonies from above: circular, margin entire, convex, cottony appearance, dark brown and brown concentric ring growth, mouse grey in the centre; reverse: dark brown at the margin, black in the centre.

Materials examined: Sri Lanka, North Western Province, Kurunegala District, Pilessa, N 7.464732 E 80.401004, on dried grains of Oryza sativa, 19 Feb. 2019, H.S. Ferdinandez, USJ-H-057, living culture USJCC–0075; ibid., USJ-H-052, living culture, USJCC–0074; ibid., USJ-H-045, living culture USJCC–0072.

Known hosts and distribution: Oryza sativa in Australia (Khemmuk et al. 2016); Epipremnum pinnatum (Wang et al. 2018) and Saccharum officinarum (Raza et al. 2019) in China; Sansevieria trifasciata in Malaysia (Kee et al. 2020); Panicum spp., Saccharum officinarum, and Oryza sativa in Thailand (Manamgoda et al. 2012a); Festuca sp., Microstegium sp., and Paspalum sp. in USA (Manamgoda et al. 2015); Oryza sativa in Sri Lanka (this study).

Notes: Isolates USJCC–0072, USJCC–0074, and USJCC–0075 were identified as C. asiatica. Fresh isolates were collected from dried grains of Oryza sativa. Curvularia asiatica has so far been recorded in Australia, China, Malaysia, Thailand, and USA (Farr & Rossman 2022). To our knowledge, this is the first record of C. asiatica from Sri Lanka.

Curvularia chiangmaiensis Y. Marín et al., Mycosphere 8: 1565. 2017. MycoBank MB 822082. Fig. 5.

Fig. 5.

Curvularia chiangmaiensis (USJCC–0064). A. Host: lesions on leaf of Pennisetum pedicellatum. B–D. Seen-day-old colony on PDA, CMA, and MEA, respectively. E. Conidiophore. F, G. Conidia attached to conidiophores. H–J. Conidia. Scale bars: E = 6 μm, F, G = 8 μm, H–J = 3 μm.

On leaf lesions of Pennisetum pedicellatum. Asexual morph: On CMA hyphae 4–5 μm wide, hyaline, septate, branched. Conidiophores (65–)91–262(–427) × (3–)4–6(–8) μm (x̄ = 177 × 5 μm, n = 20), pale brown to dark brown, mostly subhyaline at the apex, micronematous to macronematous, septate, simple or branched, straight or flexuous with subnodulose and nodulose intercalary swellings, geniculate at the apex. Conidiogenous cells (6–)7–11(–13) × 4–5(–6) μm (x̄ = 9 × 5 μm, n = 20), subhyaline, rarely brown, smooth-walled, subcylindrical to slightly swollen, terminal, mono- to polytretic. Conidia (20–)21–24(–25) × (7–)8–10(–11) μm (x̄ = 22 × 9 μm, n = 30), hyaline to pale brown, mostly ellipsoidal, straight, sometimes curved, mostly enlarged third cell from base, 3-distoseptate; hila 1–2 μm wide, flat, darkened. Sexual morph not observed.

Culture characteristics: Colonies on PDA reaching 51 mm diam after 7 d at 25 °C, colonies from above: circular, margin entire, convex, cottony appearance, white at the margin, grey aerial mycelia; reverse: brown at the margin, black in the centre. Colonies on CMA reaching 73 mm diam after 7 d at 25 °C, colonies from above: circular, margin entire, flat, hairy appearance, white at the margin, pale brown concentric ring growth; reverse: pale brown at the margin, brown in the centre. Colonies on MEA reaching 70 mm diam after 7 d at 25 °C, colonies from above: circular, margin entire, convex, cottony appearance, dark green and grey concentric ring growth, mouse grey in the centre; reverse: dark brown at the margin, black in the centre.

Materials examined: Sri Lanka, North Western Province, Kurunegala District, Dambadeniya, N 7.378799 E 80.161981, on leaves of Pennisetum pedicellatum, 24 Oct. 2018, H.S. Ferdinandez, USJ-H-018, living culture USJCC–0064; Western Province, Gampaha District, Minuwangoda, N 7.170841 E 79.942587, on leaves of Panicum virgatum, 24 Oct. 2018, H.S. Ferdinandez, USJ-H-017, living culture USJCC–0022; Western Province, Gampaha District, Minuwangoda, N 7.170841 E 79.942587, on leaves of Cyperus rotundus, 24 Oct. 2018, H.S. Ferdinandez, USJ-H-037, living culture USJCC–0069; Western Province, Gampaha District, Ja-Ela, N 7.079222 E 79.906035, on leaves of Oryza sativa, 31 Jan. 2019, H.S. Ferdinandez, USJ-H-040, living culture USJCC–0070; North Central Province, Anuradhapura District, Thuruwila, N 8.247372 E 80.419233, on dried leaves of Panicum virgatum, 13 Jun. 2019, D.S. Manamgoda, USJ-H-074, living culture USJCC–0087; Uva Province, Monaragala District, Wellawaya, N 6.729670 E 81.104552, on leaves of Ischaemum sp., 21 Dec. 2021, H.S. Ferdinandez, USJ-H-116, living culture USJCC–0144.

Known hosts and distribution: Saccharum officinarum in China (Raza et al. 2019); Zea mays in Thailand (Marin-Felix et al. 2017b); Cyperus rotundus, Ischaemum sp., Oryza sativa, Panicum virgatum, and Pennisetum pedicellatum in Sri Lanka (this study).

Notes: Isolates USJCC–0022, USJCC–0064, USJCC–0069, USJCC–0070, USJCC–0087, and USJCC–0144 were identified as C. chiangmaiensis. So far, C. chiangmaiensis has only been recorded from Saccharum officinarum (Raza et al. 2019) and Zea mays (Marin-Felix et al. 2017b). All six fresh isolates collected from Cyperus rotundus, Ischaemum sp., Oryza sativa, Panicum virgatum, and Pennisetum pedicellatum in Sri Lanka update the novel host-fungal association records herein. To our knowledge, this is the first record of C. chiangmaiensis from Sri Lanka.

Curvularia falsilunata M. Raza et al., Fungal Diversity 99: 54. 2019. MycoBank MB 556659. Fig. 6.

Fig. 6.

Curvularia falsilunata (USJCC–0053). A. Host: leaf blights on Zea mays. B–D. Seven-day-old colony on PDA, CMA, and MEA, respectively. E, F. Conidia attached to conidiophores. G, H. Conidia. Scale bars: E, F = 6 μm; G, H = 7 μm.

Leaf blight on Zea mays. Asexual morph: On CMA hyphae 3–4 μm wide, hyaline, septate, branched. Conidiophores (71–)87–244(–318) × 4–7(–9) μm (x̄ = 166 × 5 μm, n = 20), hyaline to pale brown, micronematous to macronematous, septate, simple or branched, mostly straight, sometimes flexuous. Conidiogenous cells (7–)8–13(–16) × 4–5(–6) μm (x̄ = 11 × 5 μm, n = 20), hyaline to pale brown, smooth-walled, subcylindrical, terminal or intercalary, mono- to polytretic. Conidia (18–)21–24(–26) × (5–)7–9(–10) μm (x̄ = 23 × 8 μm, n = 30), hyaline to pale brown, ellipsoidal, slightly curved, 3-distoseptate; hila inconspicuous. Chlamydospores 11–16 μm diam, pale brown to dark brown, globose to subglobose, thick-walled, grouped as chains or clumps, terminally and intercalary. Sexual morph not observed.

Culture characteristics: Colonies on PDA reaching 57 mm diam after 7 d at 25 °C, colonies from above: circular, margin undulate, slightly convex, cottony appearance, pale brown at the margin, dark brown and mouse grey concentric ring growth; reverse: dark brown at the margin, black in the centre. Colonies on CMA reaching 74 mm diam after 7 d at 25 °C, colonies from above: circular, margin entire, flat, hairy appearance, white at the margin, brown in the centre concentric ring growth; reverse: pale brown at the margin, dark brown in the centre. Colonies on MEA reaching 71 mm diam after 7 d at 25 °C, colonies from above: circular, margin undulate, flat, hairy appearance, dark brown at the margin, black in the centre; reverse: black in the centre to margin.

Materials examined: Sri Lanka, North Western Province, Kurunegala District, Nagollagama, N 7.728825 E 80.291368, leaf blights on Zea mays, 19 Dec. 2018, H.S. Ferdinandez, USJ-H-035, living culture USJCC–0053; North Western Province, Kurunegala District, Nagollagama, N 7.727944 E 80.280785, leaf spots on Echinochloa crus-galli, 19 Dec. 2018, H.S. Ferdinandez, USJ-H-034, living culture USJCC–0067; Uva Province, Monaragala District, Siyambalanduwa, N 6.892415 E 81.5454107, leaf blight on Panicum maximum, 21 Dec. 2021, H.S. Ferdinandez, USJ-H-112, living culture USJCC–0140.

Known hosts and distribution: Saccharum officinarum in China (Raza et al. 2019); Echinochloa crus-galli, Panicum maximum, and Zea mays in Sri Lanka (this study).

Notes: Isolates USJCC–0053, USJCC–0067, and USJCC–0140 were identified as C. falsilunata. Saccharum officinarum is the only reported host for C. falsilunata so far (Raza et al. 2019). The fresh isolates were collected from Echinochloa crus-galli, Panicum maximum and Zea mays during this study. Thus, novel host-fungal association records are updated herein. To our knowledge, this is the first record of C. falsilunata from Sri Lanka.

Curvularia geniculata (Tracy & Earle) Boedijn, Bull. Jard. Bot. Buitenz, 3 Sér. 13: 129. 1923. MycoBank MB 265873. Fig. 7.

Fig. 7.

Curvularia geniculata (USJCC–0073). A–C. Seven-day-old colony on PDA, CMA, and MEA, respectively. D. Conidiophore. E. Immature conidium attached to conidiophore. F. Germinating conidium. G–I. Conidia. Scale bars: D, E = 7 μm; F = 6 μm; G–I = 3 μm.

Basionym: Helminthosporium geniculatum Tracy & Earle, Bull. Torrey Bot. Club 23: 207. 1896

Synonyms: Cochliobolus geniculatus R.R. Nelson, Mycologia 56: 778. 1964.

Pseudocochliobolus geniculatus (R.R. Nelson) Tsuda et al., Mycologia 69: 1118. 1978.

On leaves of Saccharum officinarum. Asexual morph: On CMA hyphae 3–4 μm wide, hyaline, septate, branched. Conidiophores (60–)104–274(–355) × 5–8(–9) μm (x̄ = 189 × 6 μm, n = 20), pale brown to dark brown, micronematous to macronematous, septate, simple or branched, straight or flexuous, geniculate at the apex. Conidiogenous cells 6–10(–11) × (4–)5–6 μm (x̄ = 8 × 5 μm, n = 20), subhyaline to pale brown, smooth-walled, subcylindrical, terminal or intercalary, mono- to polytretic. Conidia (15–)17–23(–29) × (7–)8–11(–13) μm (x̄ = 20 × 9 μm, n = 30), hyaline to pale brown apical and basal cells, dark brown middle cells in matured conidia, straight or slightly curved, mostly ellipsoidal, sometimes obovoid, dark brown middle septa, enlarged middle cells, 3–4-distoseptate; hila 2–3 μm wide, protruding, darkened. Sexual morph not observed.

Culture characteristics: Colonies on PDA reaching 67 mm diam after 7 d at 25 °C, colonies from above: circular, margin entire, slightly raised, cottony appearance, pale brown at the margin, white and grey in the centre; reverse: pale brown at the margin, dark brown in the centre. Colonies on CMA reaching 76 mm diam after 7 d at 25 °C, colonies from above: circular, margin entire, flat, hairy appearance, white at the margin, mouse grey and pale brown in the centre; reverse: white at the margin, pale brown in the centre. Colonies on MEA reaching 77 mm diam after 7 d at 25 °C, colonies from above: circular, margin entire, slightly raised, cottony appearance, dark brown at the margin, black in the centre; reverse: black centre to margin.

Materials examined: Sri Lanka, Uva Province, Monaragala District, Sewanagala, N 6.404432 E 80.833103, on leaves of Saccharum officinarum, 20 Feb. 2019, H. S. Ferdinandez, USJ-H-046, living culture USJCC–0073; Western Province, Gampaha District, Yakkala, N 7.073656 E 80.032788, on grains of Oryza sativa, 20 Aug. 2018, H.S. Ferdinandez, USJ-H-004, living culture USJCC–0021, Western Province, Gampaha District, Minuwangoda, N 7.170841 E 79.942587, on leaves of Panicum virgatum, 24 Oct. 2018, H.S. Ferdinandez, USJ-H-012, living culture USJCC–0063; Central Province, Matale District, Palapathwela, N 7.556333 E 80.610611, on panicle of Sorghum sp. (Traditional-Swayanjatha), 12 Mar. 2019, D.S. Manamgoda, USJ-H-058, living culture USJCC–0037; Southern Province, Hambantota District, Mamadala, N 6.163880 E 80.957413, on leaf of Zea mays, 7 Aug. 2019, H.S. Ferdinandez, USJ-H-080, living culture USJCC–0039; North Central Province, Anuradhapura District, Thambuttegama, N 8.180449 E 80.321654, on leaves of Ischaemum sp., 13 Jun. 2019, H. S. Ferdinandez, USJ-H-071, living culture USJCC–0084.

Known hosts and distribution: Plurivorous and cosmopolitan (Farr & Rossman 2022); Ischaemum sp., Oryza sativa, Panicum virgatum, Saccharum officinarum, Sorghum sp. (Traditional-Swayanjatha), and Zea mays in Sri Lanka (this study).

Notes: Isolates USJCC–0021, USJCC–0063, USJCC–0073, USJCC–0037, USJCC–0084 and USJCC–0039 were identified as C. geniculata. Curvularia geniculata has been recorded as cosmopolitan fungus that most common in tropical regions from various host plant families. Six fresh isolates mentioned here were collected from Ischaemum sp., Oryza sativa, Panicum virgatum, Saccharum officinarum, Sorghum sp. (Traditional-Swayanjatha), and Zea mays. To our knowledge, this is the first record of C. geniculata from Sri Lanka.

Curvularia lonarensis Roh. Sharma & Rah. Sharma, Front. Microbiol. 7: 10. 2016. MycoBank MB 814557. Fig. 8.

Fig. 8.

Curvularia lonarensis (USJCC–0082). A–C. Seven-day-old colony on PDA, CMA, and MEA, respectively. D. Conidiophore. E. Conidia attached to conidiophore. F–H. Conidia. Scale bars: D, E, G, H = 6 μm; F = 7 μm.

On leaf spots (approx. 5 cm long) of Saccharum officinarum. Asexual morph: On CMA hyphae 4–5 μm wide, hyaline, septate, branched. Conidiophores (75–)132–260(–321) × (4–)5–7(–8) μm (x̄ = 196 × 6 μm, n = 20), pale brown to dark brown, micronematous to macronematous, septate, simple or branched, straight or flexuous, geniculate at the apex. Conidiogenous cells (6–)8–15(–18) × 5–6(–7) μm (x̄ = 11 × 6 μm, n = 20), subhyaline to pale brown, subcylindrical to swollen, terminal or intercalary, mono- to polytretic. Conidia (19–)20–26(–32) × (7–)8–12(–13) μm (x̄ = 23 × 10 μm, n = 30), hyaline to pale brown basal cell, dark brown matured conidia, straight or curved, mostly asymmetrical, sometimes Y-shaped, dark brown septa, enlarged middle cells, 3-distoseptate; hila 1–2 μm wide, flat, darkened. Sexual morph not observed.

Culture characteristics: Colonies on PDA reaching 87 mm diam after 7 d at 25 °C, colonies from above: circular, margin entire, flat, black centre, dark green at the margin; reverse: black centre to margin. Colonies on CMA reaching 86 mm diam after 7 d at 25 °C, colonies from above: circular, margin entire, flat, cottony appearance, white at the margin, grey and brown concentric ring growth; reverse: pale brown at the margin, dark brown in the centre. Colonies on MEA reaching 87 mm diam after 7 d at 25 °C, colonies from above: circular, margin entire, flat, dark brown to black from centre to margin; reverse: black from centre to margin.

Material examined: Sri Lanka, North Central Province, Anuradhapura District, Thuruwila, N 8.251407 E 80.421112, on leaf of Saccharum officinarum, 13 Jun. 2019, H.S. Ferdinandez, USJ-H-068, living culture USJCC–0082.

Known hosts and distribution: From a hyper alkaline and saline lake called “Lonar” in India (Sharma et al. 2016); Saccharum officinarum in Sri Lanka (this study).

Notes: Isolate USJCC–0082 was identified as C. lonarensis. The fresh isolate was collected from a leaf spot on Saccharum officinarum. Curvularia lonarensis has only recorded from a sample collected from a lake called “Lonar” in India. To our knowledge, this is a novel host record of C. lonarensis on Saccharum officinarum and first report from Sri Lanka.

Curvularia lunata (Wakker) Boedijn, Bull. Jard. Bot. Buitenz, 3 Sér.  13: 127. 1933. MycoBank MB 269889. Fig. 9.

Fig. 9.

Curvularia lunata (USJCC–0132). A. Host: small leaf spots on Zea mays. B–D. Seven-day-old colony on PDA, CMA, and MEA, respectively. E. Conidiophore. F, G. Conidia attached to conidiophore. H–J. Conidia. Scale bars: E–G = 5 μm; H–J = 3 μm.

Basionym: Acrothecium lunatum Wakker, De Ziektan van het Suikerriet op Java: 196. 1898.

Synonyms: Cochliobolus lunatus R.R. Nelson & F.A. Haasis, Mycologia 56: 316. 1964.

Pseudocochliobolus lunatus (R.R. Nelson & F.A. Haasis) Tsuda et al., Mycologia 69: 1118. 1978.

Helminthosporium caryopsidum Sacc, Ann. Mycol. 12: 313. 1914

Curvularia caryopsidum (Sacc.) S.C Teng., Bull. Soc. Sci. Nat. Saône-et-Loire, ser. 2: 760. 1964.

On leaf spots (approx. 0.5 cm long) of Zea mays. Asexual morph: On CMA hyphae 3–4 μm wide, hyaline, septate, branched. Conidiophores (59–)64–95(–116) × 3–4 μm (x̄ = 80 × 4 μm, n = 20), hyaline to pale brown, micronematous to macronematous, septate, simple or branched, straight, sometimes flexuous, swollen at the base and apex. Conidiogenous cells (6–)7–11(–12) × 4–7(–8) μm (x̄ = 9 × 6 μm, n = 20), hyaline, smooth-walled, swollen, terminal or intercalary, mono- to polytretic. Conidia (16–)19–23(–26) × (6–)7–9 μm (x̄ = 21 × 8 μm, n = 30), hyaline to pale brown, straight or curved, ellipsoidal, asymmetrical, enlarged third cell from base, 3–4-distoseptate; hila 1–2 μm wide, flat, darkened. Chlamydospores 7–10 μm diam, dark brown, globose, rarely subcylindrical, grouped as clumps, terminal or intercalary. Sexual morph not observed.

Culture characteristics: Colonies on PDA reaching 83 mm diam after 7 d at 25 °C, colonies from above: circular, margin entire, slightly convex, cottony appearance, pale brown at the margin, brown and grey mycelia in concentric ring growth; reverse: dark brown at the margin, black in the centre. Colonies on CMA reaching 85 mm diam after 7 d at 25 °C, colonies from above: circular, margin entire, flat, hairy appearance, white at the margin, pale brown and grey concentric ring growth; reverse: pale brown at the margin, dark brown in the centre. Colonies on MEA reaching 87 mm diam after 7 d at 25 °C, colonies from above: circular, margin entire, flat, cottony appearance, dark green margin, dull green to dark brown centre; reverse: dark brown at the margin, black in the centre.

Materials examined: Sri Lanka, Uva Province, Monaragala District, Wellawaya, N 6.609018 E 81.134455, on leaf spots of Zea mays, 21 Dec. 2021, H.S. Ferdinandez, USJ-H-124, living culture USJCC–0132; North Western Province, Kurunegala District, Uhumiya, N 7.466806 E 80.303167, on leaf of Panicum virgatum, 24 Oct. 2018, H.S. Ferdinandez, USJ-H-019, living culture USJCC–0023.

Known hosts and distribution: Plurivorous and cosmopolitan (most common in tropical regions) (Farr & Rossman 2022); Panicum virgatum and Zea mays (this study).

Notes: Isolates USJCC–0132 and USJCC–0023 were identified as C. lunata. The fresh isolates were collected from Panicum virgatum and Zea mays. So far, C. lunata was recorded from Oryza sativa in Sri Lanka (Sivanesan 1987, Adikaram & Yakandawala 2020). To our knowledge, this is the first record of C. lunata from Panicum virgatum and Zea mays in Sri Lanka.

Curvularia muehlenbeckiae Madrid et al., Persoonia 33: 56. 2014. MycoBank MB 806055. Fig. 10.

Fig. 10.

Curvularia muehlenbeckiae (USJCC–0027). A–C. Seven-day-old colony on PDA, CMA, and MEA, respectively. D, E. Conidia attached to conidiophore. F, G. Conidia. Scale bars: D = 7 μm; E = 8 μm; F, G = 6 μm.

Saprobic on dried panicle of Sorghum sp. (Traditional-Swayanjatha). Asexual morph: On CMA hyphae 3–4 μm wide, hyaline, septate, branched. Conidiophores (94–)113–212(–255) × (5–)6–8 μm (x̄ = 162 × 7 μm, n = 20), hyaline to pale brown, micronematous to macronematous, septate, simple or branched, flexuous, sometimes geniculate at the apex. Conidiogenous cells (6–)8–14(–17) × (4–)5–7(–8) μm (x̄ = 11 × 6 μm, n = 20), hyaline to pale brown, smooth-walled, subcylindrical to irregularly shaped, terminal or intercalary, mono- to polytretic. Conidia (17–)19–22(–27) × (9–)10–12(–14) μm (x̄ = 21 × 11 μm, n = 30), hyaline to pale brown apical and basal cells, pale brown to dark brown middle cells, straight or curved, usually ellipsoidal, sometimes asymmetrical or Y-shaped, rarely clavate, dark brown middle septa, enlarged middle cells, 3-distoseptate; hila inconspicuous. Sexual morph not observed.

Culture characteristics: Colonies on PDA reaching 79 mm diam after 7 d at 25 °C, colonies from above: circular, margin entire, flat, hairy appearance, pale brown at the margin, dark green to olive green from centre to periphery, concentric ring growth; reverse: olive green at the margin, dark brown in the centre. Colonies on CMA reaching 61 mm diam after 7 d at 25 °C, colonies from above: circular, margin irregular, flat, hairy appearance, white at the margin, grey in the centre; reverse: grey at the margin, black in the centre. Colonies on MEA reaching 84 mm diam after 7 d at 25 °C, colonies from above: circular, margin entire, flat, hairy appearance, dark green and olive green concentric ring growth, black in the centre; reverse: pale brown at the margin, black in the centre.

Material examined: Sri Lanka, Central Province, Matale District, Palapathwela, N 7.556333 E 80.61061, on panicle of Sorghum sp. (Traditional-Swayanjatha), 12 Mar. 2019, D.S. Manamgoda, USJ-H-061, living culture USJCC–0027.

Known hosts and distribution: Oryza sp. in Australia (Khemmuk et al. 2016); Cunninghamia lanceolate (Cui et al. 2020), Saccharum officinarum (Raza et al. 2019), and Zizania latifolia (Chen et al. 2021) in China; Muehlenbeckia sp. in India (Madrid et al. 2014); Sorghum bicolor in Japan (Heidari et al. 2018); Sorghum halepense in Mexico (Olivas-Peraza et al. 2022); Sorghum sp. in USA (Heidari et al. 2018); Sorghum sp. (Traditional-Swayanjatha) in Sri Lanka (this study).

Notes: Isolate USJCC–0027 was identified as C. muehlenbeckiae. The fresh isolate was collected on a dried panicle of Sorghum sp. (Traditional-Swayanjatha). Curvularia muehlenbeckiae has so far recorded in Australia, China, India, Japan, Mexico, and USA (Farr & Rossman 2022). To our knowledge, this is the first record of C. muehlenbeckiae from Sri Lanka.

Curvularia plantarum M. Raza et al., Fungal Diversity 99: 61. 2019. MycoBank MB 556664. Fig. 11.

Fig. 11.

Curvularia plantarum (USJCC–0091). A. Host: leaf lesions on Zea mays. B–D. Seven-day-old colony on PDA, CMA, and MEA, respectively. E. Conidiophore. F. Conidia attached to conidiophore. G. Conidia. Scale bars: E = 8 μm; F = 16 μm; G = 5 μm.

Leaf spots on Zea mays. Asexual morph: On CMA hyphae 3–4 μm wide, hyaline, septate, branched. Conidiophores (142–)167–312(–410) × 5–7 μm (x̄ = 240 × 6 μm, n = 20), pale brown, hyaline towards the apex, septate, simple or branched, flexuous, micronematous to semi-macronematous, geniculate. Conidiogenous cells (5–)6–11(–13) × (3–)4–5(–6) μm (x̄ = 8 × 5 μm, n = 20), hyaline to pale brown, smooth-walled, subcylindrical to irregularly shaped, terminal or intercalary, mono- to polytretic. Conidia (19–)21–25(–28) × (7–)9–11(–12) μm (x̄ = 23 × 10 μm, n = 30), hyaline apical and basal cells, pale brown to dark brown middle cells, mostly ellipsoidal, sometimes Y-shaped or ovate, straight or curved, enlarged middle cells, 3–4-distoseptate; hila 1–2 μm wide, slightly protruding. Sexual morph not observed.

Culture characteristics: Colonies on PDA reaching 82 mm diam after 7 d at 25 °C, colonies from above: circular, margin entire, flat, glistening surface, hairy appearance, pale olivaceous grey to white at the margin, olivaceous black and malachite green concentric ring growth; reverse: dark brown at the margin, black in the centre. Colonies on CMA reaching 87 mm diam after 7 d at 25 °C, colonies from above: circular, margin entire, flat, hairy appearance, white at the margin, grey and white concentric ring growth; reverse: pale brown at the margin, dark brown in the centre. Colonies on MEA reaching 83 mm diam after 7 d at 25 °C, colonies from above: circular, margin entire, flat, hairy appearance, pale olivaceous grey at the margin, olivaceous green in the centre; reverse: black in the centre to margin.

Materials examined: Sri Lanka, Southern Province, Galle District, Imaduwa, N 6.008556 E 80.373444, on leaves of Zea mays, 30 Aug. 2018, H.S. Ferdinandez, USJ-H-011, living culture USJCC–0054; North Western Province, Kurunegala District, Nagollagama, N 7.727944 E 80.280785, leaf spots on Echinochloa crus-galli, 19 Dec. 2018, H.S. Ferdinandez, USJ-H-036, living culture USJCC–0068; North Central Province, Anuradhapura District, Thuruwila, N 8.247372 E 80.419233, on leaf of Zea mays, 13 Jun. 2019, H.S. Ferdinandez, USJ-H-064, living culture USJCC–0078; Southern Province, Hambantota District, Mamadala, N 6.163880 E 80.957413, on leaf spots of Zea mays, 7 Aug. 2019, H.S. Ferdinandez, USJ-H-081, living culture USJCC–0091; Central Province, Matale District, Dambulla, N 7.903257 E 80.670494, on leaf spots of Zea mays, 15 Aug. 2019, H.S. Ferdinandez, USJ-H-088, living culture USJCC–0097; North Western Province, Puttalam District, Garayakgama, N 7.793702 E 79.955101, on panicles of Oryza sativa, 29 Jan. 2020, H.S. Ferdinandez, USJ-H-092, living culture USJCC–0033.

Known hosts and distribution: Saccharum officinarum in China (Raza et al. 2019); Eleusine coracana, Oryza sativa, Panicum virgatum, and Paspalum sp., in Sri Lanka (Ferdinandez et al. 2021); Echinochloa crus-galli, Oryza sativa, and Zea mays in Sri Lanka (this study).

Notes: Fresh isolates USJCC–0054, USJCC–0091, USJCC–0078, and USJCC–0097 which were collected from Zea mays, USJCC–0068 from Echinochloa crus-galli, and USJCC–0033 from Oryza sativa were identified as C. plantarum. Curvularia plantarum was first reported from Saccharum officinarum in China. Later on, Ferdinandez et al. (2021) reported C. plantarum in Sri Lanka from Eleusine coracana, Oryza sativa, Panicum virgatum, and Paspalum sp. Thus, the occurrence of C. plantarum on Echinochloa crus-galli, and Zea mays update the novel host-fungal association records herein.

Curvularia pseudobrachyspora Y. Marín et al., Mycosphere 8: 1569. 2017. MycoBank MB 822085. Fig. 12.

Fig. 12.

Curvularia pseudobrachyspora (USJCC–0024). A–C. Seven-day-old colony on PDA, CMA, and MEA, respectively. D, E. Conidiophores with immature conidia. F. Conidia attached to conidiophore. G, H. Conidia. Scale bars: D, E = 7 μm; F = 9 μm; G, H = 3 μm.

Saprobic on panicles of Zea mays. Asexual morph: On CMA hyphae 3–4 μm wide, hyaline, septate, branched. Conidiophores (70–)98–184(–204) × 5–6 μm (x̄ = 141 × 6 μm, n = 20), pale brown to brown, micronematous to macronematous, simple, septate, straight or flexuous. Conidiogenous cells (6–)7–13(–16) × (3–)4–5(–6) μm (x̄ = 10 × 5 μm, n = 20), hyaline to pale brown, smooth-walled, subcylindrical to swollen, terminal or intercalary, mono- to polytretic. Conidia (16–)19–23(–25) × (7–)8–9(–10) μm (x̄ = 21 × 9 μm, n = 30), hyaline or pale brown basal and apical cells, pale brown to dark brown middle cells, straight or curved, ellipsoidal or asymmetrical, 3-distoseptate; hila inconspicuous. Sexual morph not observed.

Culture characteristics: Colonies on PDA reaching 49 mm diam after 7 d at 25 °C, colonies from above: circular, margin entire, flat, hairy appearance, pale brown at the margin, dull green and mouse grey concentric ring growth; reverse: brown at the margin, dark green in the centre. Colonies on CMA reaching 57 mm diam after 7 d at 25 °C, colonies from above: circular, margin entire, flat, hairy appearance, white at the margin, grey and brown concentric ring growth; reverse: grey at the margin, brown in the centre. Colonies on MEA reaching 67 mm diam after 7 d at 25 °C, colonies from above: circular, margin entire, flat, velvety appearance, dull green and brown concentric ring growth; reverse: dark brown in the centre to margin.

Materials examined: Sri Lanka, Central Province, Matale District, Palapathwela, N 7.556333 E 80.61061, on panicle of Zea mays, 8 Nov. 2018, D.S. Manamgoda, USJ-H-030, living culture USJCC–0024; North Central Province, Anuradhapura District, Thuruwila, N 8.247372 E 80.419233, on leaves of Panicum virgatum, 13 Jun. 2019, D.S. Manamgoda, USJ-H-072, living culture USJCC–0085.

Known hosts and distribution: Pennisetum sp. in Denmark (Marin-Felix et al. 2020); Cocos nucifera in Ghana (Lekete et al. 2022); Acorus calamus in India (Srivastava et al. 2019); Areca catechu (Wang et al. 2019) and Lilium brownii var. viridulumin (Zeng et al. 2020) in China; Eleusine indica (Marin-Felix et al. 2017b) and Oryza sativa (Marin-Felix et al. 2020) in Thailand; Agropyron repens (Marin-Felix et al. 2020), Cannabis sativa (Marin et al. 2020), Pennisetum glaucum, and Trisetum sp. in USA (Marin-Felix et al. 2020); Panicum virgatum and Zea mays in Sri Lanka (this study).

Notes: Isolates USJCC–0024 and USJCC–0085 were identified as C. pseudobrachyspora. According to the phylogram (Fig. 1), two fresh isolates are closely related to C. pseudobrachyspora and C. protuberans. Ellipsoidal to obovoid conidia of C. pseudobrachyspora [(16–)21.5–27(–28.5) × 8–14 μm] are closer to morphological data from the fresh isolates in this study. Conidia of C. protuberans are obovoid to asymmetrical and smaller (9.5–25.5 × 6–19.5 μm) than the above-mentioned species. To date, C. pseudobrachyspora has never been reported from Panicum virgatum and Zea mays. Thus, novel host-fungal association records are updated herein. To our knowledge, this is the first record of C. pseudobrachyspora from Sri Lanka.

Curvularia verruculosa Tandon & Bilgrami ex M.B. Ellis, Mycol. Pap. 106: 20. 1966. MycoBank MB 329454. Fig. 13.

Fig. 13.

Curvularia verruculosa (USJCC–0028). A–C. Seven-day-old colony on PDA, CMA, and MEA, respectively. D. Conidiophore. E. Conidiophore with immature conidia F. Conidia attached to conidiophore. G, H. Conidia. Scale bars: D–F = 12 μm; G, H = 6 μm.

Leaf blights on Oryza sativa. Asexual morph: On CMA hyphae 3–4 μm wide, hyaline, septate, branched. Conidiophores (50–)85–248(–333) × 4–7(–8) μm (x̄ = 167 × 5 μm, n = 20), hyaline to pale brown, micronematous to macronematous, septate, simple, forming clamps at the base, straight or flexuous. Conidiogenous cells (7–)9–19(–22) × 4–6(–7) μm (x̄ = 14 × 5 μm, n = 20), hyaline to pale brown, smooth-walled, subcylindrical to slightly swollen, terminal or intercalary, mono- to polytretic. Conidia (18–)22–28(–31) × (6–)8–10(–11) μm (x̄ = 25 × 9 μm, n = 30), hyaline to pale brown, curved, obovoid or asymmetrical, enlarged middle cells, 3-distoseptate; hila inconspicuous. Chlamydospores 12–15 μm diam, dark brown, subglobose or cylindrical, thick-walled, terminally and intercalary. Microconidiation is observed. Sexual morph not observed.

Culture characteristics: Colonies on PDA reaching 26 mm diam after 7 d at 25 °C, colonies from above: irregular, margin undulate, slightly convex, velvety appearance, dull green at the margin, mouse grey in the centre; reverse: dark green at the margin, black in the centre. Colonies on CMA reaching 37 mm diam after 7 d at 25 °C, colonies from above: circular, margin entire, flat, hairy appearance, white at the margin, grey in the centre, dark brown to periphery, concentric ring growth; reverse: pale brown at the margin, dark brown in the centre. Colonies on MEA reaching 28 mm diam after 7 d at 25 °C, colonies from above: circular, margin undulate, convex, velvety appearance, dull green at the margin, grey in the centre; reverse: black centre to margin.

Materials examined: Sri Lanka, North Western Province, Puttalam District, Eluwankulama, N 8.273258 E 79.875740, leaf blights on Oryza sativa, 29 Jan. 2020, H.S. Ferdinandez, USJ-H-100, living culture USJCC–0028; Southern Province, Hambantota District, Mamadala, N 6.163880 E 80.957413, on leaf of Zea mays, 7 Aug. 2019, H.S. Ferdinandez, USJ-H-090, living culture USJCC–0031; North Western Province, Puttalam District, Garayakgama, N 7.793702 E 79.955101, leaf spots on Saccharum officinarum, 29 Jan. 2020, H.S. Ferdinandez, USJ-H-098, living culture USJCC–0103.

Known hosts and distribution: Plurivorous and cosmopolitan (Farr & Rossman 2022), Oryza sativa, Saccharum officinarum, and Zea mays in Sri Lanka (this study).

Notes: Isolates USJCC–0028, USJCC–0031, and USJCC–0103 were identified as C. verruculosa. It has been recorded from subtropical and tropical regions all over the world from a variety of host plant families. The fresh isolates were collected from Oryza sativa, Saccharum officinarum, and Zea mays during this study. To our knowledge, this is the first record of C. verruculosa from Sri Lanka.

DISCUSSION

The pleosporalean genus Curvularia is a well-established monophyletic genus in the Dothideomycetes with a wide geographic range. However, morphological characters and ITS sequences alone are insufficient to accurately identify individual species. Thus, majority of the recent publications have effectively used additional markers [i.e. 28S/large subunit of the nuclear ribosomal DNA (LSU), gapdh, second-largest subunit of RNA polymerase II (rpb2), and tef1] (Hernández-Restrepo et al. 2018, Manamgoda et al. 2012, 2015, Madrid et al. 2014, Marin-Felix et al. 2017a, 2017b, Tan et al. 2018, Marin-Felix et al. 2020). During the last five years, a considerable number of new Curvularia species have been introduced (Hyde et al. 2017, Marin-Felix et al. 2017a, b, 2020, Dehdari et al. 2018, Heidari et al. 2018, Liang et al. 2018, Mehrabi-Koushki et al. 2018, Tan et al. 2018, Tibpromma et al. 2018, Kiss et al. 2020, Raza et al. 2019, Zhang et al. 2020, Ferdinandez et al. 2021).

In this study, sequences of 36 fresh isolates were compared with those from type cultures as well as published reference cultures for species of Curvularia. Multi-locus phylogenetic analyses from a combined data set of ITS, gapdh, and tef1 along with morphological attributes were employed to identify species and confirm the morphological differences of novel species. Both novel species C. aurantia and C. vidyodayana were collected from specimens of two major poaceous crops in Sri Lanka, Zea mays and Oryza sativa, respectively. Other than the novel species, new host records were updated for C. chiangmaiensis, C. falsilunata, C. lonarensis, C. plantarum, and C. pseudobrachyspora. Moreover, five species (C. asiatica, C. geniculata, C. lunata, C. muehlenbeckiae, and C. verruculosa) represent new records for the mycobiota of Sri Lanka. These new records reveal the need for redefining the host range and geographic distribution of species within the genus. Even though the species described here are generally minor pathogens, endophytes or saprobes, more concern should be noted as they can cause devastating diseases by switching life modes (Rai & Agarkar 2016). The present study is helpful as it conveys information necessary for future studies on control and management of fungi occurring in commercially important poaceous crops including Oryza sativa, Saccharum officinarum, Sorghum sp., and Zea mays. Moreover, description of these species improves knowledge of their host ranges and updates the checklist of fungi from Sri Lanka.

Conflict of interest

The authors declare that there is no conflict of interest.