Identification and screening of nitrogen-efficient cotton genotypes under low and normal nitrogen environments at the seedling stage

Table 1 Agronomic and N traits of 100 cotton genotypes grown in low and normal N environments

N level		Height /cm	SPAD value	ADW /g	RDW /g	TDW/g	ANU /mg	RNU /mg	TNU /mg	NUtE /(g DW^.g⁻¹ plant N)	NUpE /(g plant N^. g⁻¹ soil N)
Low N	Range	6.63~ 17.83	29.7~ 41.88	1.09~ 3.14	0.73~ 1.79	1.83~ 4.73	13.10~ 63.80	4.52~ 21.79	18.07~ 68.32	48.76~ 165.98	0.45~ 1.71
	Mean	12.53	33.73	2.23	1.36	3.6	28.88	8.8	37.68	97.14	0.94
	CV	18.06	6.7	16.85	15.94	15.5	22.84	28.76	18.6	13.62	18.45
Normal N	Range	10.02~ 25.67	26.98~ 41.45	1.8~ 4.68	0.89~ 2.08	2.69~ 6.40	36.60~ 102.77	10.04~ 30.2	46.64~ 127.29	37.24~ 69.48	0.12~ 0.32
	Mean	17.72	36.62	2.8	1.42	4.22	71.76	18.93	90.7	47.01	0.23
	CV	17.57	7.44	17.64	17.63	16.6	19.14	20.82	17.55	13.22	17.55
N level		**	**	**	**	**	**	**	**	**	**
Genotype		**	**	**	**	**	**	**	**	**	**
G*N		**	**	**	**	**	**	**	**	**	**

* and ** indicate significant difference at P < 0.05 and P < 0.01 level respectively, the same below; ADW aboveground dry weight, RDW root dry weight, TDW total dry weight, ANU aboveground nitrogen uptake, RNU root nitrogen uptake, TNU total nitrogen uptake, NUtE nitrogen utilization efficiency, NUpE nitrogen uptake efficiency