Table 1. Biparental testcross population parameters, number of lines and number of polymorphic low-density and GBS SNPs within 19 maize biparental populations, and heritability of target trait–environment combinations (GY, AD and PH in WW and SS environments).

Pop. no.	Pedigree	Tester	Pop. type	Na	Nb	Nc	Heritability
							GY_WW	GY_SS	AD_WW	AD_SS	PH_WW	PH_SS
1	P1 × P2	T1	F2	165	201	62 776	0.31	0.32	0.56	0.53	0.82	0.31
2	P2 × P3	T1	F2	162	188	56 891	0.22	0.18	0.54	0.40	0.69	0.69
3	P2 × P4	T1	F2	126	183	55 583	0.35	0.00	0.34	0.31	0.52	0.44
4	P2 × P5	T1	F2	163	209	65 223	0.27	0.00	0.56	0.44	0.39	0.22
5	P4 × P1	T1	F2	183	208	60 039	0.40	0.07	0.33	0.38	0.63	0.56
6	P6 × P7	T1	F2	173	195	48 662	0.37	0.00	0.71	0.73	0.76	0.21
7	P8 × P9	T1	F2	181	212	52 546	0.40	0.26	0.74	0.51	0.61	0.40
8	P8 × P7	T1	F2	184	212	55 039	0.55	0.10	0.77	0.59	0.80	0.34
9	P10 × P11	T1	F2	184	211	58 594	0.29	0.16	0.56	0.45	0.75	0.61
10	P12 × P13	T1	F2	174	194	55 301	0.31	0.11	0.53	0.52	0.74	0.06
11	P14 × P15	T2	BC1F2	184	170	54 208	0.11	0.01	0.60	0.50	0.81	0.37
12	P14 × P16	T2	BC1F2	184	165	53 761	0.28	0.05	0.64	0.39	0.71	0.26
13	P17 × P18	T2	BC1F2	184	185	70 728	0.45	0.35	0.64	0.34	0.75	0.52
14	P18 × P19	T2	BC1F2	160	162	52 468	0.44	0.27	0.68	0.56	0.62	0.39
15	P19 × P15	T2	BC1F2	178	176	49 126	0.00	0.38	0.61	0.41	0.66	0.02
16	P15 × P5	T1	BC1F2	184	183	67 178	0.31	0.00	0.65	0.57	0.78	0.52
17	P20 × P17	T2	F2	173	166	61 036	0.45	0.27	0.70	0.50	0.88	0.56
18	P21 × P22	T2	BC1F2	176	172	78 005	0.00	0.21	0.72	0.55	0.79	0.57
19	P22 × P23	T2	BC1F2	155	184	66 109	0.39	0.39	0.69	0.62	0.77	0.36
			Avg	172	188	58 731	0.31	0.16	0.61	0.49	0.71	0.39

Abbreviations: AD, anthesis day; GBS, genotyping-by-sequencing; GY, grain yield; PH, plant height; SNP, single-nucleotide polymorphism; SS, water-stressed; WW, well-watered.

^aNumber of lines in each biparental population.

^bNumber of polymorphic low-density SNPs in each biparental population.

^cNumber of polymorphic GBS high-density SNPs in each biparental population.