TABLE 1.

Frequency distribution of NDVI and CHL in the Chinese soybean germplasm population.

Trait	Pop.	Midpoint and frequency											N	Mean	Range	h2 (%)
NDVI		0.06	0.07	0.08	0.09	0.10	0.11	0.12	0.13	0.14	0.15	≥0.16
	Entire	22	34	35	26	34	27	53	48	26	22	14	341	0.11	0.05–0.18	78.3
	WA	19	26	18	7	2	1	2	1	0	0	0	76	0.07a	0.05–0.13
	LR	2	3	8	6	8	8	17	13	6	6	6	83	0.11b	0.06–0.18
	RC	1	5	9	13	24	18	34	34	20	16	8	182	0.12b	0.06–0.17
CHL		≤2.50	2.70	2.90	3.10	3.30	3.50	3.70	3.90	4.10	4.30	≥4.50
	Entire	4	16	22	22	46	50	69	60	30	13	5	337	3.57	1.20–4.78	69.2
	WA	4	13	19	11	13	6	5	1	0	1	1	74	3.08a	1.20–4.49
	LR	0	1	2	4	13	16	20	13	6	5	3	83	3.68b	2.73–4.78
	RC	0	2	1	7	20	28	44	46	24	7	1	180	3.72b	2.67–4.50

Pop.: Population. N: the number of accessions.NDVI: normalized difference vegetation index, measured on the 21st day after sowing; CHL: chlorophyll index, measured on the 24th day after sowing. h², trait heritability.WA, wild accessions; LR, cultivated farmer landraces; RC, released modern cultivars.^a,bdifferent letters indicate significant differences between subpopulations based on t-tests at a significance level of 0.01.