Molecular Markers And Analysis Of Fertility Restorer Genes Rf1and Against Cytoplasmic Male Sterility In Wheat(Tr1ticum Aestivum L.)

In our country and even all over the world, wheat is one of the most important food crops.The improvement of the wheat output plays a very vital role in Chinese national economy andsocial stability. Effective and sufficient utilization of heterosis is one of the most importantand effective ways to promote crop yield and quality. Cytoplasmic male sterility (CMS) is acomprehensive, maternal genetic trait in the higher plant kingdom. T-type CMS (T-CMS) withTriticum timopheevi L. cytoplasm is an important CMS type in wheat and has been proven tobe promising in the hybrid seed production. It is much more stable for environment than otherCMS, and until now many T-type sterile lines (and its corresponding maintainer lines) withexcellent agronomic traits have been breeded by many breeders. However, it is very difficultto obtain ideal restorer lines with excellent agronomic traits in consideration of the narrowrestorer sources as well as the need of multitudinous fertility restorer (Rf) genes. Inheritancestudies of the restoring genes laid the theoretical foundation for breeding restorers. DNAmolecular markers assisted selection (MMAS) will greatly promote the efficiency and theaccuracy of the restorer breeding. In addition, we may directly locate the Rf genes on thechromosomes (or the chromosomes arms), and this may provide the foundation for cloning Rfgenes.In this study, we analyzed the inheritance of major Rf genes in T-CMS restorer line R113,and mapped the Rf genes in R113by SSR and ISSR markers associated with BSA(Bulkedsegregant analysis).The main results are as follows:(1)Through the genetic analysis of an F2population, derived from ms(S)Aikang58/R113,the result indicated that the restorer line R113is influenced by two major Rf genes(Rf1andRf4) and some minor enhance genes of fertility.(2)196sets of SSR markers which were located on the1st chromosome group (includingchromosomes1A、1B and1D)and the6th chromosome group (including chromosomes6A、6B and6D)were screened for polymorphism between the parents and the two builded genepools. Seven primer pairs were found polymorphic of the restorer genes.(3)Linkage analysis indicated that the microsatellite locus Xgwm136, Xgpw7062andXgdm33located on chromosome1AS were found to be linked to the restorer gene Rf1with the estimated genetic distance of4.8cM,9.6cM and13.7cM, respectively, with an order ofXgdm33, Xgwm136, Rf1and Xgpw7062. Xgpw1079, Xgwm193, Xgpw7011and Xgwm508located on chromosome6BS were found to be linked to the restorer gene Rf4with theestimated genetic distance of3.4cM,6.8cM,13.7cM and21.5cM, respectively, with anorder of Xgpw7011, Xgpw1079, Rf4, Xgwm193and Xgwm508.(4)Out of the selected42ISSR primers, primer UBC840between the parents and the twobuilded gene pools were amplified the stable and consistent polymorphisms. Geneticanalysis showed that the genetic distance between the ISSR marker loci UBC840-460andthe Rf gene was15.2cM.The breeding for new fertility restorer lines of T-CMS(or S-CMS) in wheat would befacilitated by using the7SSR markers and the1ISSR marker.