| Wheat stripe(or yellow) rust, caused by Puccinia striiformis f. sp. tritici (Pst), is one of the mostdamaging diseases of wheat (Triticum aestivum L.) worldwide, also an epidemics in the largest region ofChina. Genetic resistance is a more effective, economic and environment-friendly way to control thedisease. However, it is always easy for race specific resistance cultivars to lose its resistance because of theregularity of race. In order to solve such a problem, geneticists and plant breeders paid more attention tosearching new resistant germplasms, and realized the diversification of wheat varieties, pyramiding genesinto new wheat varieties. Elymus mollis (Trin) Hara showed a high resistance to stripe rust, and its hybridprogeny had a similar characteristic. This study made a seedling test, a situ hybridization analysis and amolecular mapping for wheat-Elymus mollis(Trin) Hara derivative M8664-3, obtaining the followingresults:1. The M8664-3was highly resistant to six Pst races of China(CYR29、CYR31、CYR33、Su11-4、Su11-7and T4).2. To determine the resistance genes in the derivative, M8664-3was crossed with susceptible genotypeMingxian169. The seedings of F1,F2,and F2:3generations were tested with race CYR33under controlledgreenhouse conditions. The genetic results indicated that one single dominant gene in M8664-3confersresistance to CYR33.The gene for resistance to CYR33was temporarily designated as YrM8664-3. Fivepolymorphic SSR markers were linked to the resistance gene. The genetic distances of the two closestflanking markers, Xgpw2331and Xgpw3224, were2.8and8.1centimorgans, respectively.3. The resistance gene was assigned to chromosome4AL by SSR marker positions database andnullisomic-tetrasomic analysis. Based on molecular detection for fourteen wheat-Elymus mollis(Trin) Haraderivatives and wheat cultivars from Huanghuai wheat region, chromosomal location and pedigree analysis,YrM8664-3should be a new resistance gene to stripe rust. |
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