我国北方不同年代玉米杂交种产量及穗部性状的遗传增益

Study on Genetic Gains of Yield and Ear Characters of Different Eras Maize Hybrids in North China

以北方地区不同年代有代表性的玉米杂交种及其亲本为试材,对产量杂种优势的遗传增益及穗部性状杂种优势变化进行探讨。结果表明:(1)随着品种更替产量逐年提高;(2)各穗部性状随年代的推移都有不同程度的改良,单产的提高是各穗部性状协同作用的结果;(3)穗粗和籽粒深度是1990年以后杂交种产量增长的主要遗传增益;(4)产量的增长与杂种优势增加并不一致。

Genetic gains of yield heterosis and heterosis changes of ear characters were discussed using different eras maize hybrids and their parents representatively in north China as study materials. The results showed that ： （ 1 ） Yield increased year by year with the replacement of hybrids. （2） Each ear characters modified in different degrees with the lapse of years, and unit yield improvement was the results of synergistic actions of various ear properties. （3） Ear width and kernel depth were the two major genetic gains of yield improvement after the 1990 s. （4）Yield improvement was not consistent with the increasing of heterosis.