Table 1.

Leaf chlorophyll-content traits in the ZH RIL population across different environments

Traits	Parents Average		RILs Lines Average				Skewness	Kurtosis	Year, seasons and growth stages
	ZH24a	HX3a	Minimuma	Maximuma	Meana	SD
TSP	58.94 ± 0.82	54.58 ± 0.98	39.96	59.92	52.43	4.28	− 0.70	− 0.43	2017Spr-R1
MSP	48.17 ± 1.19	46.40 ± 1.27	29.50	55.64	46.35	4.20	−0.30	0.13
BSP	43.37 ± 1.14	41.71 ± 1.64	24.58	51.60	40.55	4.09	−10.00	0.68
ASP	50.16 ± 0.55	47.56 ± 0.59	37.30	54.90	46.46	3.31	−0.23	−0.43
TSP	58.06 ± 0.52	53.57 ± 1.08	40.92	60.60	51.34	3.41	−0.16	0.16	2017Spr-R4
MSP	55.37 ± 1.43	52.82 ± 0.66	37.00	58.46	47.29	3.27	0.21	1.17
BSP	47.06 ± 1.35	46.57 ± 1.51	35.34	53.60	42.87	2.90	0.27	0.74
ASP	53.50 ± 0.44	50.98 ± 0.32	39.58	54.70	47.16	2.59	−0.23	0.42
TSP	54.94 ± 1.24	50.40 ± 1.12	35.72	58.40	49.60	4.59	−0.24	− 0.85	2017Spr-R6
MSP	48.17 ± 0.66	46.40 ± 1.89	33.50	54.44	43.72	4.73	0.25	−0.93
BSP	44.37 ± 1.22	41.71 ± 0.89	24.58	47.00	37.83	4.37	0.48	−0.14
ASP	49.16 ± 0.59	46.17 ± 0.73	34.20	50.82	43.71	3.65	0.02	−0.60
TSP	44.19 ± 1.54	37.89 ± 1.84	31.00	45.36	39.34	2.87	−0.30	−0.58	2017Sum-R1
MSP	42.90 ± 1.18	37.32 ± 0.92	29.66	45.84	38.07	3.22	−0.20	−0.26
BSP	36.47 ± 1.09	33.57 ± 1.26	22.62	41.40	33.57	3.44	−0.55	0.42
ASP	41.19 ± 0.62	36.26 ± 1.17	30.02	43.34	37.00	2.37	−0.29	0.27
Chl_Aa	15.12 ± 1.09	9.88 ± 0.60	3.84	20.26	10.39	3.12	0.26	0.04
Chl_Ba	4.49 ± 0.27	2.89 ± 0.26	1.17	5.79	3.01	0.82	0.52	0.43
Chl_A/B	3.41 ± 0.30	3.55 ± 0.42	1.89	5.56	3.43	0.45	1.50	8.33
TSP	42.39 ± 1.71	40.24 ± 1.02	30.90	54.22	41.24	3.81	0.25	0.54	2017Sum-R4
MSP	42.42 ± 0.96	46.23 ± 1.19	29.70	52.18	41.50	4.40	0.04	−0.37
BSP	36.22 ± 1.25	35.89 ± 1.07	26.88	55.94	37.62	4.36	0.10	0.92
ASP	40.34 ± 0.33	40.79 ± 0.54	30.84	48.14	40.12	3.43	−0.09	−0.38
Chl_Aa	7.04 ± 0.55	8.93 ± 0.36	2.97	15.29	8.92	1.95	0.12	0.50
Chl_Ba	3.24 ± 0.20	3.10 ± 0.07	1.22	6.70	3.55	0.96	0.54	0.50
Chl_A/B	2.23 ± 0.28	2.88 ± 0.11	1.34	4.07	2.59	0.49	−0.09	−0.40
TSP	41.85 ± 1.38	41.33 ± 0.73	31.00	52.94	41.21	4.60	0.00	−0.56	2017Sum-R6
MSP	40.46 ± 0.95	41.73 ± 1.23	23.56	52.80	41.02	4.42	−0.50	0.92
BSP	35.72 ± 0.80	33.10 ± 0.85	22.24	44.30	32.72	3.75	−0.42	0.71
ASP	39.34 ± 0.69	38.72 ± 0.81	29.58	46.30	38.51	3.26	−0.13	−0.55
Chl_Aa	5.17 ± 0.25	4.73 ± 0.31	2.17	5.65	3.38	0.77	0.35	−0.47
Chl_Ba	3.21 ± 0.40	2.83 ± 0.31	0.43	3.76	2.12	0.68	0.56	−0.31
Chl_A/B	1.75 ± 0.30	1.76 ± 0.24	0.90	3.91	1.68	0.48	1.38	2.41

TSP Top leaves SPAD value, MSP Mid leaves SPAD value, BSP Bottom leaves SPAD value, ASP Average SPAD value, Chl_A Chlorophyll a content, Chl_B Chlorophyll b content, Chl_A/B Chlorophyll a/b ratio, ZH24 ‘Zhonghuang 24’, HX3 ‘Huaxia 3’, ^a mg/g, 2017Spr: the spring of 2017, 2017Sum: the summer of 2017, R1 R1 growth stage, R4 R4 growth stage, R6 R6 growth stage