SSR Analysis and Identification of Fertility Restorer Genes Rf1 and Rf4 of Triticum timopheevii Cytoplasmic Male Sterility (T-CMS) in Wheat (Triticum aestivum L.)
Abstract：In order to explore the fertility characteristics of Triticum timopheevii cytoplasmic male sterility(T-CMS), and to furtherly provide the theoretical and technical support for taking advantage of T-type sterile lines to breed hybrid wheat (Triticum aestivum L.) by using molecular assisted breeding, restorer and sterile DNA pools were established using the extremly sterile and fertile plants among the F2 population of ms(S)Aikang 58/R113, respectively. A hundred and nity six sets of SSR markers which were located on the 1st and 6th chromosome groups were screened for polymorphism between the 2 parents. The results showed that 3 markers which located on the chromosome 1AS and 4 markers which located on the chromosome 6BS were found to be amplified stably polymorphic bands between the parents and the 2 gene pools. Linkage analysis indicated that the microsatellite locus Xgwm136, Xgpw7062 and Xgdm33 located on chromosome 1AS were found to be linked to the restorer gene Rf1 with the estimated genetic distance of 4.8, 9.6 and 13.7 cM, respectively, with an order of Xgdm33, Xgwm136, Rf1 and Xgpw7062. Xgpw1079, Xgwm193, Xgpw7011 and Xgwm508 located on chromosome 6BS were found to be linked to the restorer gene Rf4 with the estimated genetic distance of 3.4, 6.8, 13.7 and 21.5 cM, respectively, with an order of Xgpw7011, Xgpw1079, Rf4, Xgwm193 and Xgwm508. The result also showed that the fertility of T-CMS restorer R113 in wheat was mainly influenced by 2 major fertility restorer genes(Rf1 and Rf4) and some minor enhance genes of fertility. The breeding for new fertility restorer lines of T-CMS(or S-CMS) in wheat would be facilitated by using the seven SSR markers，which can effectively improve the selection efficiency of the corresponding restorer.
