Validation Of Genetic Effects And Fine Mapping Of QTL For Protein Content In Rice

Rice（Oryza sativa L.）is one of our main food crops which also provides energy for more than half of the population in the world every day.The importance of rice is self-evident.The nutritional quality of rice is related to human health in areas where rice is the main food.Protein content is one of the most important factors affecting the nutritional quality of rice.There are a lot of reports about QTL（quantitative trait loci）mapping of rice protein content,but only two genes controlling protein content cloned from natural population through map-based cloning currently,Os AAP6 and Os Glu A2,others were most obtained from mutant studies.With the rise of bioinformatics,the emergence of gene chips has brought great convenience to QTL mapping and gene cloning.In this study,two F₂populations were used to detect multiple quantitative trait loci（QTL）that control the protein content of rice,and we validate their effects,one of them was fine mapped.Results are as follows:1.Construct two F₂populations from hybridization of Pusa,an Indica line,and H2613S,C815S,two two-line sterile lines respectively.Examine the protein content by near-infrared and Kjeldahl methods respectively.Based on the genetic linkage map constructed by RICE6K chip,four QTL controlling protein content were detected.2.In the summer of 2018,we developed SSR and SNP markers on both sides of the detected QTL interval,four BC₁F₅segregation populations were developed to verify their genetic effects respectively.Only two QTL were verified with significant differences,q PC2 and q PC4.Through local mapping,two QTL were detected in the region of q PC4 with LOD values greater than 2.5,named q PC4.1 and qPC4.2 respectively.3.In the summer of 2019,100 recombinants of q PC2 were planted in Wuhan for progeny testing,and finally finely mapped to 570 kb.