Genetic Basis Dissection For Fertility Stability And Stigma Exsertion Rate Of Cytoplasm Male Sterile Line In Rice

In this study, based on recombinant inbred lines derived from the cross of Zhongguo Xiangdao and Chuanxiang 29B,a genetic linkage map were constructed. Crossing Chuanxiang 29A with each line of recombinant inbred lines(RILs) in order to make a testcross F1 population withg genetic background of cytoplasmic male sterility to map quantitative trait loci (QTLs) for natural seed-setting rate, bagged seed-setting rate, single stigma exsertion rate, double stigma exsertion rate, stigma exsertion rate and pollen fertility rate and breed sterile lines with genetic background of Chuanxiang 29. These results are as follows:1.Based on recombinant inbred lines, a genetic linkage map were developed containing 144 SSR markers, which covers a total of 1884.7cM with an average interval of 12.9cM.2.Investigated natural seed-setting rate, bagged seed-setting rate and pollen fertility rate in the testcross F1 population,7 QTLs were detected. Two QTLs for natural seed-setting rate were located on the chromosome 6,11,respectively; There were 2 QTLs for bagged seed-setting rate, locating on the chromosome 6,11,respectively; three QTLs for pollen fertility rate were identified on chromosome 3,4,6.Based on natural seed-setting rate, baged-setting rate and pollen fertility rate, we identified 2 QTLs related to fertility stability of rice sterile line.Zhongguo Xiangdao alleles of all QTLs for fertility stability of rice sterile line contributed to an increase in each trait and most QTLs showed a small effect.3.There were 3 QTLs for rice stigma exsertion rate, located on chromosome 1,2, 11;4 QTLs for rice single stigma exsertion rate, located on chromosome 1,2,11,12;3 QTLs of double stigma exsertion rate were located on chromosome 1,2,11.These QTLs expained 6.25 to 34.85% of total phenotypic variation. Three intervals for the three traits were detected on the chromosomel,2,11, indicating these regions were major regions for stigma exsertion. All the favorable QTLs related to rice stigma exsertion were orignated from alleles of Chuanxiang 29B.