【摘要】 以3个杂交组合的亲本及4个世代(F1,F2,F3,F4)为试验材料,对亲本、F1代及各分离世代个体,依12个农艺性状的表现,分别计算了协调指数。结果表明,3个组合的F1代协调指数均小于亲本,说明在各性状协调性方面,亦存在杂种优势;分离世代的个体单株粒重与协调指数间存在着明显的负相关关系;以单株粒重大而协调指数小的类型为优良变异类型,不同组合各世代优良变异类型出现的几率存在差异;如果在各分离世代不加以选择时,优良变异类型出现的频率有随世代增加而下降的趋势。建议应在协调指数小的基础上,加强早期分离世代对优良变异类型的选择,以增大后期世代优良变异类型出现的比率,提高育种效率。更多还原

【Abstract】 The harmonizing indexes(h)of parents and plants in4generations(F 1 s ,F 2 s ,F 3 s ,F 4 s)of3crosses were calculated respectively.The results showed that the h of F 1 was smaller than that of its parents in each cross and the heterosis of F 1 could be presented in harmonizing aspect among traits;the significant minus correlation between h and grain weight per plant in every separating generations was found;the plant with lower h and larger grain weight per plant in every separating generation was thought to be a better one,difference of the ratio of this kind was detected among generations.The ratio of the kind would decline,as increasing of the generation without selection of this one.The suggestion was that the selection of elite variants should be conduct - ed in the early generation in order to increase the rates of the better plants in the later generations and result in a higher effects of genetic improvement.更多还原