Mapping Of Genes For Grain Shape And Analysis Of Genetic Effects Based On SSSLs In Rice(Oryza Sativa L.)

The grain shape of rice(Oryza sativa L.)is closely related to yield and appearance quality,and the research on it has attracted wide attention in recent years,more and more genes that effect rice grain shape have been cloned,but the vast majority of them cloned from mutants,which is difficult to applicable to the production practice directly;Moreover,the genetic interaction between grain shape genes is limited by the complex genetic background,and we know little about it.In this study,the new grain shape genes were identified by using the SSSLs(single segment substitution lines)which constructed through our laboratory,which laid a foundation for the study of the cloning and genetic interaction of new grain shape genes.The main achievements of the study include:1.A major QTL located on chromosome 10 that controls the grain shape of rice was identified through single segment substitution line P24,was named qGW10.This QTL locus can explain the 68.32 % of phenotypic variation.We detected qGW10 located at the region of 176.779 kb on chromosome 10 by developing mapping population derived from a cross between HJX74(recurrent parent)and the single segment substitution line P24(donor parent).this gene may has a significant influence on the 1000-grain weight,panicle length and the development of first panicle branch.2.qGL1.1,the other major QTL which located on chromosome 01 detected by single segment substitution lines R36 and R41,controls grain shape in rice.This QTL locus can explain the 12.25 % of phenotypic variation.We detected qGL1.1 located at the region of 489.177 kb on chromosome 01 by developing mapping population derived from a cross between HJX74(recurrent parent)and the single segment substitution lines R36 and R41(donor parent).Except for the regulation of grain length,this gene has a significant influence on the 1000-grain weight,and has no effect on other phenotypic traits.3.The double-gene pyramiding lines of qGW10 and qGL1.1 with other known genes for grain shape were constructed,which laid the material foundation for the subsequent analysis of genetic interaction.This study has laid a good foundation for map-based cloning and function studies of qGW10 and qGL1.1,which will better helpful for understanding of the genetic regulatory mechanism of grain shape in rice,and it also provides theoretical basis and material guarantee for the design breeding of high yield and quality cooperative improvement in rice.