. 2017 Jul 25;12(7):e0181541. doi: 10.1371/journal.pone.0181541

Table 7. Summary mean squares and significance tests of combining ability effects for yield and growth traits under water stress conditions on potato families tested in set I and set II at Adet, Ethiopia.

Source of variation	d.f.	TTY	MTY	ATW	GC	PHT	CC
Set I
Replication	1	0.0042^ns	0.0070^ns	86.81^***	1.334^ns	100.77^*	5.23^ns
GCA_f	3	0.0186^***	0.0154^***	95.86^***	103.679^ns	228.16^***	0.71^ns
GCA_m	3	0.0135^**	0.0218^***	114.11^***	70.696^ns	129.11^***	23.15^***
SCA	9	0.0084^**	0.0110^***	102.39^***	88.735^ns	36.26^*	8.15^**
Error	15	0.0017	0.0017	2.15	35.778	12.13	1.53
CV (%)		11.778	13.5466	6.39	13.612	7.9	2.81
Mean		0.3495	0.3006	22.95	43.941	44.07	44.01
R²		0.8739	0.8972	0.98	0.711	0.89	0.87
GCA/(GCA+SCA)%		65.5515	62.8355	50.63	49.56	83.12	59.4
GCAf/GCAm ratio		1.3768	0.7059	0.84	1.467	1.77	0.03^**
Set II
Replication	1	0.0018^ns	0.0006^ns	26.19^*	104.904^**	73.44^**	8.02^*
GCA_f	3	0.0133^**	0.0118^***	59.27^***	153.191^***	88.84^***	39.93^***
GCA_m	3	0.0159^***	0.0214^***	356.91^***	200.199^***	212.98^***	38.62^***
SCA	9	0.0074^**	0.0053^**	46.39^***	87.584^***	29.00^**	2.48^ns
Error	15	0.0015	0.001	3.6	10.958	4.92	1.03
CV (%)		10.292	9.646	7.19	7.051	4.38	2.34
Mean		0.3775	0.3339	26.38	46.946	50.66	43.39
R²		0.8732	0.9047	0.97	0.922	0.94	0.95
GCA/(GCA+SCA)%		66.4819	75.8768	81.77	66.859	83.88	94.06
GCAf/GCAm ratio		0.8377	0.553	0.17	0.765	0.42	1.03

d.f., degree of freedom; TTY, total tuber yield (kg plant^-1); MTY, marketable tuber yield (kg plant^-1); ATW, average tuber weight (g); GC, groundcover (%); PHT, plant height (cm); CC, chlorophyll content (SPAD reading); GCA, general combining ability; GCA_f, general combining ability for female; GCA_m, general combining ability for male; SCA, specific combining ability; R², coefficient of determination.

significant at

*** p < 0.001

** p < 0.01

* p < 0.05

non-significant at p value 0.05.