谷子两系杂交组合的杂种优势及亲本配合力分析

Analysis of Heterosis and the Parental Combining Ability on Two-Line Hybrid Foxtail Millet

为了解谷子两系杂种优势的亲本配合力遗传基础,本研究利用5个不育系和8个恢复系按NCII不完全双列杂交组配40份(5×8)杂种F1,对11个谷子主要农艺性状的杂种优势及配合力进行分析。结果表明,谷子两系杂交组合在穗长、穗粗、千粒重、分蘖性、单穗重、单穗粒重和产量7个性状中存在广泛的超亲优势,但除千粒重外,其余性状的显著超亲组合数较少。杂交组合的单穗重和单穗粒重与产量极显著相关,且相关系数较高。对优异亲本进行筛选发现,A2和R3为一般配合力(GCA)较好亲本,A1、A2为GCA产量效应优异亲本,A1×R3、A2×R8、A3×R5、A3×R7和A5×R1为产量特殊配合力(SCA)效应较优组合。对产量强优势组合的配合力进行分析,发现优异的两系杂交组合中包含至少1个GCA较高的亲本或拥有较高的SCA。本研究结果为谷子优异两系杂交组合的亲本选配提供了一定的理论依据。

In this study,an incomplete diallel cross using five male sterile lines and eight restorer lines with 40( 5×8)hybrid combinations was carried out to understand the genetic basis of combining ability of two-line hybrid foxtail millet.The heterosis and combining ability of 11 major agronomic traits were analyzed. The results showed that the heterosis over male parent widely existed in seven traits of two-line hybrid combinations,including ear length,spike width,1000-grain weight,tiller,ear weight,grain weight per ear,yield. However,there were a few significant heterosis over male parent combinations in all characters except 1000-grain weight. Both ear weight and grain weight per ear showed significant correlation with yield and the correlation coefficient was high. Among thirteen parents,A2 and R3 showed better general combining ability( GCA),while A1 and A2 showed better GCA effects on the yield trait. Combinations including A1×R3,A2 × R8,A3 × R5,A3 × R7 and A5 × R1 had better special combining ability( SCA) effects. By analyzing the combining ability of yield,we found that at least one parent has high GCA or the combination has high SCA in strong heterosis combinations. This study would provide theory basis for future parent selection of hybrid foxtail millet in yield.