QTL Mapping And Analysis Of Effective Panicle Number Per Plant,Filled Grains Per Panicle And 1000-grain Weight In Rice

Rice,as one of the main grain crops in the world and also the largest grain crop in China,is becoming increasingly important in the context of the continuous growth of China’s population and the continuous reduction of arable land.Effectively ensuring China’s food security is becoming increasingly important.The number of effective panicles per plant,the number of filled grains per panicle,and the weight of 1000 grains are three factors that directly affect rice yield.The exploration of excellent genes for these traits helps to analyze the mechanism of rice yield formation.In this study,the F₁₉generation recombinant inbred line population constructed with 9311 and Changhui 121 as parents was used as research materials,and combined with high-throughput sequencing technology,QTLs affecting the effective panicles per plant,grains per panicle,and 1000 grain weight of the population were located and the key QTLs for subsequent fine positioning were determined.The main results were as follows:1.Using the results of population and parental re sequencing,a genetic map was obtained based on 45607 SNP markers,including 1910 Bin markers.The total Genetic distance was 1951.68 c M,and the average Genetic distance between two markers was 1.02c M.2.The results of population phenotypic analysis showed that the three target traits were all in continuous distribution,and showed a certain degree of parental segregation.The number of grains per panicle of the population was susceptible to environmental impact but tended to normal distribution,and the 1000 grain weight and the number of effective panicles per plant tended to skewed distribution;Correlation analysis shows that there is a negative correlation between the three target traits,and there is a highly significant negative correlation between the number of effective panicles per plant and the number of filled grains per panicle,as well as between the weight of 1000 grains and the number of filled grains per panicle.3.In the positioning of two years and three seasons,a total of 21 QTLs were detected,distributed on 11 chromosomes except for chromosome 8.Among them,8 QTLs were found for the number of effective panicles per plant,with a contribution rate ranging from5.8089%to 26.2748%;QTL of 4 grains per panicle,with a contribution rate ranging from6.0633%to 9.8081%;There are 9 QTLs with a thousand grain weight,with a contribution rate ranging from 5.5128%to 11.6632%.Among the positioning results,5 QTLs were located twice,and 6 QTLs contributed more than 10%.Among them,multiple major loci such as qEPN6-1,qEPN10,qEPN11,qFGP7,qTGW7,qTGW9,qTGW12-2 are newly detected QTLs in this study.Based on the comprehensive LOD value,contribution rate,and localization frequency,QTL qEPN11,which controls the effective panicle number per plant on chromosome 11,was identified as the key focus of future research.4.By analyzing the interval where qEPN11 is located,it is located within a physical interval of approximately 67kb between 22641066 and 22709060 on chromosome 11,including 14 genes.Three of these genes have already been located,except for conservative genes,the remaining genes are involved in multiple pathways related to tillering regulation.Later,it is necessary to analyze the function of related homologous genes,further locate candidate genes,and perform functional analysis such as knockout and over expression to verify them.