两个热带玉米复合群体相互轮回选择遗传改良效益研究

Research of Genetic Improvements of Two Composited Populations after Reciprocal Recurrent Selection

利用半同胞相互轮回选择法对桂综3号和桂苏综两个热带复合群体进行两轮改良后,选用黄早四、掖478、丹340、Mo17等4个测验种作母本,各轮改良群体作父本,按NCⅡ遗传交配设计组配测交种,对各轮群体、群体间杂交组合和测交种进行选择效果评价。结果表明,桂综3号、桂苏综及其杂交组合产量平均每轮增效分别为53、645、390 kg/hm2;群体组合超亲优势由5.7%提高到13.5%。C2群体与C0相比,桂综3号的产量一般配合力效应从-5.32增加到-1.55,桂苏综的一般配合力效应从0.10增加到6.55。桂综3号、桂苏综与掖478、丹340的特殊配合力都得到一定的提高。其他农艺性状随各轮对产量相互轮选择发生不同程度的变化,其中出籽率和千粒重是随轮次改良向增加方向发展,秃尖长也随着减少,其他性状变化不大。

After two cycles genetic improvements of the composited populations Guizong3 and Guisuzong using the half-sib reciprocal recurrent selection, NC 11 mating experimental trial was designed by using Huangzao4,Ye478, Dan340 and Molt as female tester and the genetic improved populations as male.The results showed that the yields of Guizong3 and Guisuzong and their testcrosses increased 53, 645 and 390 kg/ha per cycle respectively. And the bene- fits of superiority over the better parent of inter-population crosses（MC0 × SCo） increased from 5.7% to 13.5% .The comparison between C2 and Co showed that the yield general combination ability of Guizong3 increase from -5.32 to -1.55, the yield general combination ability of Guisuzong increase from 0.10 to 6.55. Special combining ability be- tween Guizong3 , Guisuzong and Ye478, Dan340 increased in different extent.With the reciprocal recurrent selection of the yields, other traits vary in different extents. Among them, the seed yield ratio and the thousand kernel weight in- crease with the improvement cycles, and the beard tip decreased with the improvement cycles increase, and the other trait remained almost the same during the improvements.