Genetic Analysis And Molecular Markers Of The Fertility Restoration Gene On Al-type Cytoplasmic Male-sterility In Wheat

As one of the major crops in China and all over the world, wheat plays a very important role in the development of Chinese national economy and social stability.Utilization of heterosis is one of important and useful ways to improve crop production and quality.Genetic analysises of restoring genes are theoretical basis of restorers breeding.DNA molecular markers assisted selection will greatly improve efficiency and accuracy of restorer breeding.The molecular markers immediately linked to Rf genes are not only uesful for locating Rf genes on chromosomes,and also are benefit for Rf genes cloning furtherly.In this paper, genetic analysises of restoring genes and SSR markers selecting were carried out based on F2 generation of cross AL18A x 99AR144-l.The results are as follows:1. A F2 segregation population derived from 18Ax99AR144-1 was produced. X2test indicates that the fertile and sterile plants segregated in15:1 ratio. Fertility inheritance in 4 populations of 2 parents(P1 and P2), F1 and F2 from the cross (AL18A x 99AR144-1) in wheat, were investigated by the mixed major gene plus poly-genes in genetic model of quantitative traits.Results showed that the genetic model E-1 was the most suitable model for analysis of fertility restoring gene of AL-type wheat.The fertilityof AL-type wheat was controlled by two additive-dominance-epitasis major genes plus additive-dominance polygenes, and heritability of major-gene was 85.92%. The fertility restoring genes of AL-type wheat may be consist of two major genes and polygenes.The heritability of major genes was high and it would benefit for hybrid wheat selection.2. Using the method of BSA and SSR analysis,3 SSR makers named Xgwm95, Cfd60 and Barc10 from total 1465 SSR markers distributed in 21 pair of chromosome of wheat were selcted for their specificfingerpints among 4 populations of 2 parents(P1 and P2), F1 and F2 from the cross (AL18A x 99AR144-1). Linkage analysis indicated that, only Xgwm95 distributed in 2A chromosome was tightly linked to one of the two major restoration genes with a distance of 15.0cM, among the above 3 selected SSR markers.3.Based on the molecular markers linked to restoring genes in wheat reported, such as Xgwmll,Xgwml8,Xgwm136,Xgwm264,Xgwm374,Xgwm526,Xgwm550,wmc406,Dupw214,Barc61,Cfd267 and TAGLGAPR, we found that there only Barc61 has stabile polymorphisms in the 4 populations of 2 parents(P1 and P2), F1 and F2 from the cross (AL18Ax99AR144-1). Linkage analysis indicated that, Barc61 was tightly linked to one of the two major restorer genes with a distance of 18.0cM.4. To test effectivity of SSR markers Xgwm95 and Barc61 selected in restoring line breeding program, 10 random sterile lines and 5 random restoring lines were anlysed by the 2 SSR markers selected. The results show that 10 randomly selected male-sterility lines could be catalogue as one group by Xgwm95, but one of five restoring lines also detected the specific band as 99AR144-1 line.Nine of the ten male-sterility lines selected and four of five randomly selected restoring lines could be catalogue as one group by Barc61.The above results implied that combine analysis of AL-type restoring lines by Xgwm95 and Barc61 could improve the accuracy of marker assited slection.