Qtl Mapping Of Flag Leaf Length And Width Correlation Genes In Rice And Preliminary Construction Of Introgression Lines Of Rice

Rice as one of the most important food crops in the world,has always been a focus of research by breeders for its yield-related traits.The morphologically related shape of rice flag leaf can directly affect the photosynthetic efficiency of rice leaves,and thus affect the yield of rice to a certain extent.In this study,the flag leaf length,flag leaf width,flag leaf length to width ratio traits of flag leaf in rice were studied in two aspects: The first one was QTL mapping of flag leaf length and width correlation genes in indica rice.In this study,an indica rice variety gang46 B and A232 were used to construct a high generation recombinant inbred line(RIL)population.There were 178 genetically stable families.Measure data in Lingshui,Hainan province and Wuhan,Hubei province and QTL mapping was performed for the flag leaf length,flag leaf length to width ratio in rice,and 142 pairs of SSR labeled primers were used to assist the detection.The second is preliminary construction of introgression lines of rice.The main research achievements are as follows:(1)Under different environmental conditions in lingshui,hainan and wuhan,hubei,the values of flag leaf length and flag leaf width of parent gang46 B were larger than that of parent A232,but the ratio of flag leaf length to width of parent gang46 B was smaller than that of parent A232.In hainan environment,the two parents showed significant differences in flag leaf length,flag leaf width and flag leaf length-width ratio.In the environment of wuhan,the three traits of parents also showed significant difference.(2)A total of 14 QTL loci were obtained,among them,there were 5 QTLS for flag leaf width,6 QTLS for flag leaf length,and 3 QTLS for flag leaf length to width ratio.The QTL loci are distributed on chromosomes 1,2,4,6,7,10 and 12.LOD value is between 2.52 to 5.62,the contribution rate of phenotypic variation was between 5.56% and 21.27%.Performance is additive effect.(3)QTLs of flag leaf width,flag leaf length and flag leaf length-width ratio on chromosome 1 were both detected in hainan and wuhan,indicating that these QTLs were less affected by environmental factors(4)Using A232 and narrow-leaf families HC22,HC42,HC91,HC97 and HC121 that selected from RIL population as donor parents for the introduction line,rice narrow-leaf introduction line population was constructed with broad-leaf variety gang46 b as the recipient parent.After two generations of backcrossing in wuhan and hainan,6 BC2F1 groups have been obtained and the seeds have been preserved.