上海科技大学知识管理系统

Plant height is the important determinant for the yield formation of rice, and selecting of an optimal plant height is necessary during rice breeding to achieve ideal biomass and lodging resistance. In this study, allele variation ofSd1, the well-known "green revolution" gene, was clarified as the major factor for plant height segregation in the breeding populations from anindicaandjaponicacross. Two nullsd1alleles (sd1(N1),sd1(N2)) and two functionalSd1alleles (Sd1(Jap)andSd1(Ind)) were characterized by newly developed functional markers, which demonstrated high efficiency for genotyping a large set of germplasms. We found that the null alleles, which were enriched in the modernindicabut notjaponicavarieties in China, presented universal effects to shorten plant height despite the genetic backgrounds and environments. The effect of theSd1(Jap)allele for plant height was weaker than that ofSd1(Ind)but sensitive to the genetic background of different subspecies, suggesting complex epistatic interactions betweenSd1(Jap)and other plant height loci. In addition,Sd1(Jap)was identified to be compatible with some hybrid varieties recently developed in China, raising its potential value for hybrid rice breeding. Finally, we carried out a breeding practice by introgressing the nullsd1allele into the elitejaponicavariety Daohuaxiang, which suffers from severe lodging, and clarified the agronomic performance of the improved semi-dwarf line. This study will pave the way for the effective application of differentSd1alleles in both inbred and hybrid breeding in the future.