对沈综(Co、HC2、FC3)群体在轮回选择作用下农艺性状的遗传改良效果的研究

应用轮回选择方案对玉米(ZeaMaysL.)沈综HC₂群体进行改良，将得到的全姊妹FC₃群体与CoHC₂群体种植于同一环境中，根据调查考种结果对各群体的产量及农艺性状进行比较分析，结果表明群体产量获得了7.8%的遗传增益。单株粒重、穗粗、穗行数、子粒深度明显改良。伴随群体优良基因型的增多，多数与产量有关性状的变异系数略有下降。通径分析和相关分析表明，群体产量的提高是控制单株粒重的性状得到合理的改善以及这些性状之间或与其它性状之间获得协调发展的结果。结果还证实了不同改良方案的轮换，可扩大对被改良群体不同基因位点的选择压力而有效地改良群体。

Study on Improvement Effect in Shenzong(Co

Recurrent selection was used for improving population HC₂ and improved FC₃ population Was obtained.Population Co,HC₂ and FC₃ were planted in the same environment.Yield and agronomic trait were analyzed on basis of investigating results.The results showed that genetic gains of yield in the population was 7.8%.Grain weight per plant,ear weight per plant,number of rows per ear and depth of grain were improved obviously.With the elite individuals frequency increasing in the improved population.Coefficient of variability for most of the traits related to yield decreased slightly.According to the results of path and correlation analysis,the reason of yield improvement in the population was that some traits affecting kernel weight per plant were improved reasonably,and that these traits and other traits were coordinately developed.The results also showed that the change of improving methods could exert selection pressure on different gene site,which can made the method more effectively.