Inheritance Analysis And Major QTL Cloning Of Exserted Stigma Rate In Rice

Rice is the main crop in China.Since the discovery and exploit of sterile strain line and three lines of Indica hybrid rice were bred successfully.The Indica hybrid rice has made a great progress in the production.While compared to Indica rice,it is hard to study Japoniaca hybris rice because it lacks the restorer gene.Rice is a self-pollinated plant whose percentage of exserted stigma has significantly positive correlation with the hybrid seed yield.It is significant for enhancing the percentage of exserted stigma to increase the hybrid seed yield through fine mapping the QTLs with big and stable effect.There is no report on the cloning of major QTLs for percentage of exserted stigma at home until now.This study will be carried out based on the previous research result that one major QTL for percentage of exserted stigma were found on chromosome 3.In this study,fine mapping for the major QTL of the percentage of exserted stigma on chromosome 3 will use the near isogenic line based on the advanced backcrossing line and construct the molecular linkage map with increased density through synthesis the SSR,InDel or CAPS primers in the aimed region.Fine mapping and cloning of the major gene which controls the percentage of exserted stigma will be carried out.The main results were as follows,(1)The results showed that,single exserted stigma rate was in consistent with the E-1 model,dual exserted stigma rate was in consistent with E-2 model,total exserted stigma rate were in consistent with E-1 model.(2)There had no correlation significant correlation between sigma exsertion rate and spikelet length,width,length/width,width,aera,volume.The stigma length was significantly correlated with stigma exsertion rate.And the stigma span was highly significantly correlated with stigma exsertion rate.(3)With SSR/InDel polymorphism primer BC3F1 scanning group whole genome,and analyzed the target section genotype by genotype composition,analysis and character observation,selection of genetic background in BC3F1 group and 9083 of the most close to the individual,self generated approximately 6000 strain BC3F2.(4)Two major genes controlling the stigma exsertion rate,one of them is GS3.GS3 regulation of the stigma exsertion rate may be achieved by inhibiting the formation of phosphatidylethanolamine-binding protein(PEBP).This study will characterize the genetic mechanism of percentage of exserted stigma in rice and lay a good foundation for the intensive study the gene regulation.