Cytological Studies And Preliminary Mapping Of M21,a Female Semi-sterility Mutant In Rice

Deciding the rice yield,rice female gamete is one of the most important organs.Compared to pollen sterility,in terms of sterility,female gamete sterility affects the rice seed setting rate and yield much more directly.Generally,female infertility is usually caused by abnormal female gametophyte development.Molecular mechanism of rice female sterility remains largely unknown for the complexity mechanism of the female gametophyte abortion.In this study,we identified a new stable genetic female semi-sterility mutant m21 due to the partial embryo sac abortion.The cytology,genetics and gene of mutant M21 were preliminarily determined: 1.Cytological studies on the semi-sterility mutant m21 of ricePollen fertility investigation found that mutant m21 pollen fertility,pollen germination in vitro was no obviously difference between wild type and Yuefeng B;Normal mature embryo sacs of YueFeng B and various abnormal embryo sacs of m21 by Confocal laser scanning microscopy.It is sure that the main cause of the mutant m21 is semi-sterility sac abortion.2.Genetic analysis of rice mutant m21Fertility investigation found that mutant m21 showed semi sterility,and wild type Yuefeng B fertile.Yuefeng B F1 hybrids and m21 crosses the seed setting rate of normal,by test analysis found that between Yuefeng B and F1 reciprocal F1,seed setting rate had no obviously difference,m21?Yue FengB and F1,the seed setting rate significantly.the effects of BC1F1(m21//m21/N22)group spikelet rate from 15.0%-100.0%.was distributed in Proportion,there is a trough at 65.0%-70.0%,normal fertile individuals and semi sterility by chi square test with 1:1,suggesting that m21 semi-sterility phenotype is controlled by a single recessive gene.3.Construction of molecular linkage map and localization of female gamete semi-sterility geneConstructed by using 189 pairs of SSR markers covering 12 chromosomes in a genetic map,the average genetic distance between the marker 14.1cM,RM26761-RM26841 detected a female semi sterile QTL loci on chromosome eleventh,its contribution rate is 20.2%,the interval was not reported and fertility related genes.This study not only lays the foundation for the M21 gene map cloning and its function research,but also lays the theoretical foundation for the improvement of rice yield and the realization of mechanized seed production.