QTL Mapping And Effect Verification Of Rice Appearance And Cooking And Eating Quality Traits

Rice is an important food and economic crop in my country,as well as an important model plant in scientific research.Rice quality is the main factor that determines the yield of rice and the competitiveness in the market,which is co-regulated by multiple genes.In this study,we mapped QTL of grain shape,chalkiness and amylose content of rice and verified the genetic effect of a part of QTL.The main results are as follows:1.The BC₃F₂ population constructed by the predecessors using the temperate japonica rice Kongyu 131 with short round grains and low amylose content as the recurrent parent,and the tropical japonica rice Cypress with slender grain and high amylose content as the donor parent was used as the material,using 151 SSR and In Del molecular markers identified the genotypes of a total of 286 families in the BC₃F₂ population.The genetic distance between the markers was calculated by linkage analysis,and a molecular marker genetic linkage map was constructed.The total length of the map was 948.6 c M and the average distance between the markers was 6.3 c M;2.The grain shape data of a total of 286 families in the BC₃F₂ population and the phenotypic data of grain shape,chalkiness,and amylose content in a total of 286 families in the BC₃F_2:3 population were investigated.QTL mapping was performed using the CIM method,and a total of 37 QTL were mapped.Including 7 QTL for grain length,6 QTL for grain width,5 QTL for length width rate,4 QTL for white back rate,4 QTL for white belly rate,4 QTL for white core rate,6 QTL for chalkiness rate and 1 QTL for amylose content.qGL7.2,qLWR5,qLWR7.1 were repeatedly located in the 2 populations;3.In 2019 and 2020,the BC₂F_2:3 population and BC₃F_2:4 population were used to verify the genetic effects of some of the QTL mapped.In 2019,we found that there were significant or extremely significant differences between homozygous Cypress and Kongyu131 genotypes in qLWR7.2,q BR2,and q WBR1.2 population,with additive effects of 0.15,10.96%,and 8.50%respectively;in 2020 we found that there were extremely significant differences between homozygous Cypress and Kongyu 131 genotypes in qGL7.2,qGW3,and qLWR7.2 population,with additive effects of 0.36 mm,0.08 mm,and 0.15,respectively.qLWR7.2 has been repeatedly verified in two years to a very significant genetic effect.In summary,we used the Kongyu 131/Cypress backcross population as the material,combined with 151 molecular markers to construct a molecular marker genetic linkage map,and combined the population’s grain shape,chalkiness,and amylose content phenotype data for QTL mapping and effect verification.A total of 5 QTL for grain shape and chalkiness were verified to have significant or extremely significant genetic effects.This research provides a material basis for the subsequent location and cloning of QTL,and helps to improve rice quality.