轮回选择对豫综5号玉米群体产量性状配合力的改良效果

玉米群体遗传基础广泛、遗传变异丰富，是培育优良玉米自交系的源泉。玉米群体的改良研究对玉米种质资源创新、优良自交系选育具有重要的指导意义。本研究采用NC II遗传交配设计，以豫综5号5个轮次改良群体为父本，以黄早四、丹340、中综5号、齐319、掖478、Mo17为测验种配制成30个测交组合，通过一年两点的产量性状及其配合力评价试验，研究轮回选择对豫综5号群体的改良效果。结果表明，轮回选择对群体单株产量的改良是有效的，群体与各测验种间的杂交后代产量平均每轮提高3.57%。半姊妹轮回选择和相互半姊妹轮回选择在改良群体产量一般配合力方面, 均得到显著提高，呈逐轮上升的趋势；采用半姊妹轮回选择对豫综5号群体3轮的选择后，C₃群体与C₀相比，一般配合力效应值从–11.63增长到5.57，差异极显著；经1轮相互半姊妹轮回选择后，群体的一般配合力效应值从C₃的5.57增加到C₄的9.75。豫综5号改良群体与黄早四的特殊配合力得到一定的提高，逐轮朝着Reid×唐四平头杂优模式水平提高的方向稳定发展。

Improvement Efficiency of Recurrent Selection for the Combining Ability of Yield Trait in Maize Population Yuzong 5

Maize population has the extensive hereditary basis and rich hereditary variation,and therefore is the source of good inbred lines cultivated.Improvement of maize population is important to create new germplasm and breed excellent inbred lines.In this study,30 testcrossing combinations that Huangzaosi,Dan 340,Zhong Syn 5,Qi 319,Ye 478,and Mo17 crossed with five cycle improved populations according to NC II design were evaluated in two environments.The results showed that the recurrent selection method gained a good result for yield per plant of the population and the gain of hybrid grain yields of testcross combi-nations between improved populations per cycle and testing cultivars increased by 10%.Both half-sib recurrent selection(HS-RS) and half-sib reciprocal recurrent selection(HS-RRS) were good methods for improving the general combining ability(GCA) of grain yield in the populations and the GCA was improved in very cycle for the populations.After improvement of three cycles for Yuzong 5 by HS-RS,the GCA increased from -11.63 to 5.57 with highly significant probability difference at the level by C3 comparing with C0.After improvement of one cycle for Yuzong 5 by HS-RRS,the GCA increased from 5.57 to 9.75 by C4 com-paring with C3.The analysis of special combining ability(SCA) showed that the SCA of improved Yuzong 5 × Huangzaosi had certain enhancement,indicating that improvement of Yuzong 5 developed steadily toward the heterotic pattern of Reid×SiPT.