Genetic Analysis of Some Traits Related to Yield in japonica Rice Landrace from Taihu Lake Region

Three crosses derived from parents with distinctly different panicle traits, including Datoudao × Daichangqing(crossⅠ), Laolaihong × Yanjing 2(crossⅡ) and Daichangqing ×Shanghaiqing(cross Ⅲ), and their derived generations, were evaluated to analyze the genetics of yield-related traits of japonica rice landrace from Taihu Lake Region by the method of major gene plus polygene mixed inheritance model. The optimum model for total grain number per panicle in crossⅠ was one major gene plus additive-dominant polygene mixed inheritance model, while that for crossesⅡ and Ⅲ was one complete dominant major gene plus polygene mixed inheritance model. The optimum models for effective panicle number per plant in crossesⅡand Ⅲ were one major gene plus polygene, while that in cross I was two major genes. The genetic models for 1000-grain weight in crossesⅡandⅠ were two major genes plus polygene mixed inheritance model, and that in cross Ⅲ was one major gene plus polygene. The optimum model for filled grain number per panicle was two major genes model without polygene. It was suggested that segregation analysis of quantitative traits among multiple generations of P_ 1 , P_ 2 , F_ 1 , B_ 1 , B_ 2 and F_ 2 offered a higher accuracy and could identify polygene than that of single generation. Based on the genetic information provided by joint analysis of multiple generations, breeding strategies for different crosses and traits were discussed.