Genetic Analysis Of Feritility Control And QTL Mapping Of Male Sterile Gene Loci In YM-Type Thermo-Sensitive Male Sterile Wheat Line ATM3314

Two-line hybrid wheat system is an important way to use heterosis in wheat. To reveal the inheritance of male fertility of thermo-sensitive male sterile wheat lines and molecular characters of sterile gene are important for the breeding of thermo-sensitive male sterile wheat line and application of two-line hybrid wheat theoretically and practically. In this study, the inheritance of male fertility of thermo-sensitive male sterile wheat line was investigated by using 4 generations joint analysis method of mixed major gene plus polygene mixed inheritance model, which from the cross between YM-type thermo-sensitive male sterile wheat line ATM3314 and restorer line China Spring in two consecutive years. Using SSR markers analysis 200 plants of F2 segregating population in 2009 and by QTL mapping method preliminary mapped the male sterility gene of YM-type thermo-sensitive male sterile wheat line. The main results were as follows:1. Study on inheritance of male fertility in YM-type thermo-sensitive male sterile wheat lineUsing the major gene plus polygene mixed inheritance model based on the fertility data of the P1, P2, F1 and F2 populations from the cross of ATM3314/Chinese Spring in two consecutive years. The results showed that the fertility of YM-type thermo-sensitive male sterile wheat line was controlled by two additive-dominance-epitasis major genes plus polygene. The heritability of major genes were very high with 95.62% in 2008 and 90.32% in 2009, and in the 2 control of fertility major genes, the additive effects (27.986 and 27.603) and dominance effects (12.190 and 20.175) of the first main gene were higher than the second main gene (14.933 and 1.903; -0.217and 8.462 ). The additive effect of major genes has a positive effect on fertility and between the two main genes existence interactions.2. QTL mapping for male sterile gene of YM-type thermo-sensitive male sterile wheat lineThe 200 individuals of F2 population from the cross between YM-type thermo-sensitive male sterile wheat line ATM3314 and restorer line Chinese Spring were used as the mapping population, 30 SSR markers in 1Bs were screened between the parents and male sterile and fertile bulks, 5 SSR primers were selected and screened in the F2 population. Then a 1Bs partial linkage map with 5 SSR markers was constructed and used for QTL detection to the male fertility by composite interval mapping method. One major QTL loci designed as rfv1-1 and one minor QTL loci named as rfv1-2 were detected for the male sterility of YM-type thermo-sensitive male sterile line. Rfv1-1 was located between the SSR markers Xgwm18 and Xwmc406 on the 1Bs partial linkage map constructed, with a genetic distance of 6 and 4.6cM, respectively. The LOD value for the QTL detected was 8.80, additive effect was 23.87 and dominant effect was 10.44. This QTL could explain 23.91% of the phenotypic variation. Rfv1-2 was mapped between markers Xwmc406 and Xbarc8 at a genetic distance of 4 and 3.4cM, respectively. The LOD value was 3.10, additive effect was 17.59, and dominant effect was 5.99 and explaining 7.78% of the trait variation. We also screened SSR primers which uniformed distribution in the wheat chromosomes 5A, 2B, and 4B at the same time and the SSR marker Xwmc817 in chromosome 2B were selected and screened in the F2 population.