Abstract:

This experiment was conducted to study the growing and Nitrogen (N) nutrition and to screen of the nitrogen high efficiency of 33 cotton varieties through water culturing. The experiment adopted H?C?АВДОНИН ingredient water culturing and installed two N levels (1 mmol/L and 5 mmol/L) ,and every level was three repetitions, analytic the total plant dry weight, N utilization index of total plant, N concentration of plant, the total plant weight, root-top ratio of different cotton varieties. Significant positive correlations (r=0.946**, N=33, P<0.01) were observed between the relative dry weight of the whole plant with N concentration of plant, and positive correlations (r = 0.432*, N=33, P<0.05) were observed between with N utilization index of total plant. Thus, the total plant dry weight could be first screening index for low N tolerance. Positive correlations (r = 0.445*, N=33, P<0.05) were observed between N concentration of plant with N utilization index of total plant, and they could be secondary screening index for low N tolerance. The results indicated that there were great difference among cotton varieties in the low nitrogen ability, XLZ12, XLZ21, XLZ26, XLZ31, XLZ32, XH25 had higher N utilization efficiency, stronger N absorption ability, and higher N utilization index in low N level; while cultivars PTYH, XLZ 19, XH3, XH13, AJJL and XLZ 36 had lower N efficiency, fewer N absorption ability and lower N utilization index in normal N level. Our conclusion is that preliminary screening of cotton genotypes tolerant to low-potassium at the seedling stage was feasible using a hydroponic culture. However, some important genotypes would need further screening in the field.