Mapping Of Stripe Rust Resistance Genes In Common Wheat Cultivars Yunmai 53 And 94 Yi-15

Stripe rust,caused by Puccinia striiformis f.sp.tritici?Pst?,is one of the devastating diseases in wheat.Frequent virulence variation in prevalent Pst population often causes the losses of resistance for wheat cultivars.For example,recent loss of resistance of Yr26 results severe decrease in wheat production.In order to breed wheat cultivars with durable resistance,it is necessary to identify more new resistance genes in wheat.Yunmai 53 has good agronomic traits and is grown widely in Southwest region.94yi-15 is a winter wheat line with high seedling resistance to stripe rust in Gansu province.The aims of this study were to,?1?analyze of resistance to stripe rust in segregating populations of Huixianhong?susceptible?/Yuanmai53 and Huixianhong/94Yi-15,?2?identify resistance genes and linked molecular markers.1.Seedlings of parents and F₁,F_2,and F_2:3 lines of Huixianhong/Yuanmai 53 were evaluated with the Pst race CRY29.Using SSR markers,we identified a dominant resistance gene to stripe rust on chromosome 1B.The resistance gene was temporarily designated as YrYM53.The linked markers were Xbarc61,Xbarc240,and AF1/AF4 with genetic distances of 3.3 cM,3.9 cM and 7.6 cM.Further pedigree and resistance spectrum analysis demonstrated that YrYM53 was different from resistance genes on 1B or 1BL/1RS chromosome,such as Yr9,Yr10,Yr15,Yr24/Yr26 and YrCN17,indicating that it is likely to be a new stripe rust resistance gene.2.A dominant stripe rust resistance gene on chromosome 2BS was identified in an F₂ population derived from the cross of Huixianhong/94Yi-15.Using 1126 SSR markers,we found 6 markers Xbrac349,Xcfa2043,Xbrac1027,Xbrac18,Xbrac55,and Xwmc24 with polymorphism between two parents as well as between the resistant and susceptible bulks.The resistance gene Yr94yi-15 had genetic distances of 9.8 c M,5.6 cM,22.1 c M,28.9 cM,34.2 cM,and 40.7 c M from the markers Xbrac349,Xcfa2043,Xbrac1027,Xbrac18,Xbrac55 and Xwmc24,respectively.Further work is needed to confirm the relationship of Yr94yi-15 and Yr41?YrCN19?on the same chromosome.