Analysis on Combining Ability of Main Agronomic Traits to 6 Shanhui Rice Restorer Lines

【Objective】The combining ability and heritability of main agronomic traits of 6 rice restorer lines were analyzed and their application value was evaluated.【Method】6 new rice restorer lines of Shanhui series and 5 three-line sterile lines were selected and 30 hybrid rice combinations were prepared according to the 6×5 incomplete diallel cross design. And combining ability and heritability of 8 main agronomic traits were analyzed.【Result】The contribution rate of GCA genotype variance of restorer line was higher than that of sterile line in yield per plant, plant height and effective panicle number, therefore, the phenotypes of yield per plant, plant height and effective panicle number of hybrid rice combinations were mainly determined by the inheritance of restorer line. Growth period, seed setting rate, panicle length and yield per plant showed lower contribution rate of GCA genotype variance (lower than 50%), therefore, the 4 traits would be mainly influenced by non-additive effect in breeding practice; 1000-grain weight, plant height, effective panicle number and total grain number showed higher contribution rate of GCA genotype variance (higher than 55%), therefore, they are mainly affected by additive effects of genes. The narrow heritability of 1000-grain weight and plant height was 80.99% and 76.03%, which showed good stability in offspring and could be selected in low generation in breeding practice. There was no obvious correlation between GCA and SCA. Both SR02 and SR04 were elite restorer lines. According to the parent utilization value classification method, SR02 would be easy to create large-grain and high-yield hybrid rice combinations in breeding practice, which showed as Class Ⅰ parent in yield per plant and Class Ⅱ parent in seed setting rate and 1000-grain weight; SR04, showed as Class Ⅱ parent in yield per plant, effective panicle number, total grain number and seed setting rate, would be easy to create high-yield hybrid rice combinations with multiple panicles, and SR04 also showed the potential of lodging resistance. New hybrid rice combinations Tianfeng A × SR01, Jinheng A × SR06 and Jinheng A×SR03 showed the highest SCA value in per plant weight, which were 26.320, 26.049 and 20.723, respectively, and all of 3 combinations showed good utilization value.【Conclusion】In the practice of hybrid rice breeding, the selection of parents should not only pay attention to the selection of high GCA parents, but also strengthen the selection of SCA of combinations. At the same time, according to the genetic characteristics of the parents, the design of hybrid rice parental matching should follow the principle of "exploiting strengths and avoiding weaknesses, complementing traits".The inheritance of hybrid rice in yield per plant, plant height and effective panicle number are mainly affected by restorer line. SR02 and SR04 are elite restorer lines, which have good application value. New hybrid rice combinations Tianfeng A × SR01, Jinheng A × SR06 and Jinheng A × SR03 show high SCA value in yield characters, with good application prospects.