Studies on Combining Ability and Heritability in Japonica P(T)GMR
Luo Yanchang et al (Rice Research Institute, AAAS, Hefei 230031)
Using Noth Carolina Design Ⅱ(NC Ⅱ), 42 F 1 were attempted from 6 japonica PGMS lines and 7 Japonica parents. The parent's GCA and combinations' SCA,heritability and compatibility were investigated. The main result was as follow:4 good combinations were selected in Japonica hybrid rice. They were 29130S and 3502S as male sterile lines and 41678 and mp 402 as male parents.GCA action is more important than SCA action in 10 traits. In two-line japonica hybrid rice breeding, parent with a lot of good traits should be selected so that advantageous gene could be added up in F 1.Traits with higher wide heritability in japonica groups were plant height, panicle length, panicle density, 1000-grain weight and growth duration, accounting to 88.1%-92.1%. Traits with higher narrow heritability were plant height, panicle length, panicle density, growth duration and number of grain per panicle, accounting to over 70%. Those traits can be effectively selected in early generation. Some problems in two-line method of hybrid rice breeding had been discussed in the paper.