水稻氮素利用效率的选择效果

利用“Dasanbyeo/IR66746-26-3-2”和“TR22183/IR66167-27-5-6”两个杂交组合探讨了在施氮和未施氮条件下杂交早期世代对产量及氮素利用效率的选择效果。研究结果表明，在杂交早期世代对产量的直接选择效果在未施氮条件下明显高于施氮条件下，并通过产量选择对氮素利用效率进行间接选择无论在施氮区还是未施氮区均有显著效果

Selection Effect of Nitrogen Use Efficiency in Rice

Selection effects of grain yield and nitrogen use efficiency (NUE)in earlier generation were studied under N-fertilized and N-unfertilized conditions using two crosses of Dasanbyeo/IR66746-76-3-2 and TR22183/IR66167-27-5-6. Selection effect of grain yield under N-unfertilized condition was higher than that of in N-fertilized condition. Indirect selection effects of NUE by selection of grain yield under N-fertilized and N-unfertilized conditions were effective,and heritabilities of grain yield and NUE under N-unfertilized conditions were higher than those of in N-fertilized condition. Direct selection effects of NUE under N-fertilized and N-unfertilized conditions were higher, and direct selection responses of grain yield and NUE under N-unfertilized condition were higher thanthose of in N-fertilized condition. NUE was positively correlated with grain yield and harvest index respectively. Directly to select grain yield and NUE under lower nitrogen condition was more effective, and it should be selected that high yield and high harvest index in rice breeding for higher nitrogen use efficiency and higher resistance to lower nitrogen level.