半姊妹与全姊妹三轮次选择对玉米“沈综”群体改良效果的研究

本文采用半姊妹与全姊妹轮回选择方法对玉米“沈综”群体实施了三轮次改良。结果表明，两种改良方案对“沈综”群体改良皆有显著效果，半姊妹方案取得产量每轮遗传增益为１２．９１％，明显大于全姊妹方案对农艺性状所取得的遗传进度也较大。三轮选择后，群体大多数农艺性状的遗传变异度没有下降。半姊妹方案实施过程中，更换测验种可扩大对被改良群体不同基因位点的选择压力。

Improvement Effects Of Three Cycles Of Half-sib And Full-sib Recurrent Selection In Syn. ShenYang Maize Population

The experimental results show that the significant genetic gains of the grain yield and other traits have been gained by hall -sib and full-sib recurrent selection in the Syn. Shenyang maize population. The genetic gains per cycle for grain yield in population for half-sib and full -sib recurrent selection are 1 2. 91and 3. 22% , respectively. The resutls also shows that changing the tester in different cycles of half - sib selection could enhance the selection pressure on different loci in improving population and in favor of improving effect.