杂交水稻产量及农艺性状杂种优势分析

为探讨杂种优势与双亲值、双亲一般配合力（GCA）、组合特殊配合力（SCA）、双亲遗传距离的关系，利用10个不育系和10个恢复系，按不完全双列杂交配制100个组合，对杂交水稻产量及农艺性状的杂种优势进行了分析，探索杂种优势的预测方法。结果表明：杂种一代的超亲优势和对照优势主要体现在穗长、每穗总粒数、每穗实粒数几个性状上，其具有正向超亲优势组合的比例分别达到61.0%、66.0%和53.0%，具有正向对照优势的比例分别为62.0%、78.0%和79.0%，结实率性状具有正向对照优势的比例也达到58.0%。杂种优势与父母本值、父母本平均值、高亲值、低亲值及父母本差值都有较为密切的关系，超亲优势与高亲值在8个性状上都极显著相关；对照优势与母本值、父母本平均值、高亲值都呈显著或极显著正相关。杂种优势与SCA和亲本的GCA效应值密切相关，特别是对照优势与SCA和双亲的GCA都呈显著或极显著正相关，同时与父母本的GCA之差和之和都有较大的关系。杂种优势与遗传距离的关系比较复杂，当遗传距离在5~5.5范围内，双亲的距离越远，杂种优势越强。

Analysis of Heterosis in Yield and Agronomic Character of Hybrid Rice

In order to explore the relation between heterosis and parents value,the general combing ability of parents,the specific combing ability of combinations and the genetic distance,using 10 male sterile lines （maintenance line） and 10 restorer lines were used to make 100 crosses by NCⅡ design to analyze heterosis of yield and agronomic characters and explore the method of predicting heterosis.The results showed：the over-parent and contrast heterosis of hybrids mainly presented panicle length,number of grains per panicle,filled grains per panicle.The ratio of possessing positive the over-parent heterosis combinations were 61.0%,66.0% and 53.0% respectively,the ratio of possessing positive the contrast heterosis combinations were 62.0%,78.0% and 79.0% respectively.There was stronger positive contrast heterosis for seed setting rate too.Heterosis were closely related with the value of female and male,mid-parent value,high parent value,low parent value,parents differentials.There were significant correlation or very significant correlation between contrast heterosis and female parent value,average value of parents and high parent value.It was closely correlation between heterosis and specific combining ability （SCA） and parents general combining ability （GCA）.Especially,the contrast heterosis was significant positive correlation with SCA and parents GCA.Meanwhile,there was closely correlation between contrast heterosis and both differentials and sum of parents GCA.It was very complex in heterosis and genetic distance.The further parents genetic distance was,the stronger the heterosis was,as a genetic distance of 5-5.5 between two parents was.