Table 1.

Morphological, phenological, physiological, yield, and yield component traits of the MSD lines and their parent ‘Norin 61’ (N61) evaluated for heat stress tolerance at Dongola (DON), Hudeiba (HUD), Wad Medani with optimum sowing (MED/OS), and Wad Medani with late sowing (MED/LS) in Sudan

Trait	DON			MED/OS			HUD			MED/LS			Heritability
	Range	Mean	N61	Range	Mean	N61	Range	Mean	N61	Range	Mean	N61
DH	62–104	79	72	53–115	72	64	56–96	66	61	50–75	63	62	0.87
DM	99–135	110	106	88–135	108	101	94–125	107	103	85–111	97	92	0.74
GFD	10–52	32	33	11–61	36	37	19–61	40	42	20–45	33	30	0.76
PH	47–136	102	97	65–113	91	84	55–110	80	69	56–106	84	79	0.71
PL	20–53	35	34	13–57	32	82	8–32	15	13	14–39	28	26	0.76
CT	15–31	23	32	13–31	20	17	25–36	30	30	21–37	26	25	0.65
SPAD	30–54	44	43	27–68	49	50	33–58	51	51	38–60	49	50	0.70
NDVI	0.50–0.80	0.68	0.71	0.27–0.84	0.62	0.55	0.40–0.58	0.65	0.63	0.54–0.89	0.69	0.69	0.24
KS	10–30	20	23	10–65	46	56	15–55	41	45	10–65	42	54	0.81
TKW	15–55	32	33	10–55	30	30	15–40	29	27	10–40	27	26	0.88
Gm−2	2838–23268	9142	10965	2250–48000	21330	27181	2704–23874	9269	10357	2400–35200	15726	21283	0.68
GY	41–1172	637	784	13–1053	501	823	18–950	421	383	8–891	415	703	0.88
BIO	500–4850	2398	2366	300–3975	2006	2038	99–2326	1284	1279	310–3400	1833	1089	0.60
HI	2–63	27	33	1–66	25	40	6–60	33	31	2–61	23	39	0.89

DH, days to heading; DM, days to maturity; GFD, grain filling duration (days); PH, plant height (cm); PL, peduncle length (cm); CT, canopy temperature (°C); SPAD, chlorophyll content (SPAD units); NDVI, normalized difference vegetation index; KS, kernel number per spike; TKW, thousand-kernel weight (g); Gm⁻², grain number per m²; GY, grain yield (g m⁻²), BIO, biomass (g m⁻²); HI, harvest index (%).