Genetic Analysis And Molecular Mapping Of Resistance To Stripe Rust Of Derivatives From Hybrid Of Triticummonotriticum-Avena Fatua

Wheat stripe rust, caused by Puccinia striiformis f.sp tritici, is an airborne fungaldisease occurred many times pandemic in China, affecting wheat production for sustainabledevelopment limiting factor. Breeding and planting resistant varieties is the most economic,efficient and environmentally friendly methods to prevent wheat rust. The wheat geneticbasis of our country is scarce because most varieties have the same or similar resistancegenes. In recent years, with epidemic of strains CYR32et al, the main cultivars ofwheat-growing areas in China lost their resistance to stripe rust. Therefore, it must be ofgreat significance to lasting controlling strip rust to explore and create new resistancematerials and genes, to breed new rust-resistant varieties, to increase diversity of resistancegenes and provide rich material reserve for genetic transformation of wheat diseaseresistance.The wild relative species of wheat has a wealth of genetic diversity as many containabundant resistance genes of stripe rust. Using artificial distant hybridization to introduceexogenous genetic material into wheat is an effective way to create new wheat antigenicmaterials. We obtained hybridization descent series named YLP after Triticum monococcumand Avena fatua for hybridization.By using identification and screening of cytology and striperust, the paper obtained resistant lines to epidemic strains of Puccinia striiformis f.sp tritici inour country, and its genetic analysis and molecular markers were done. Achieved results areas follows:1. Five lines of YLP, YLP-1,YLP-7,YLP-9,YLP-13and YLP-16, the distanthybridization generations between Triticum monococcum and Avena fatua L., which stabilityresistant to Puccinia striiformisf. sp. tritici.(Pst) were selected as experiment materials.Cytogenetic analysis and resistance evaluation of these hybrid derivatives were done.2n=42chromosomes were observed after identification root tip in cytology and the chromosomeconfiguration of most Pollen mother cell during metaphaselofmeiosis Ⅰ were2n=21Ⅱ;Meanwhile In the pollen mother cell of F1drivided from five derivatives andChinese Spring, There were0.84univalents and20.60pairs of bivalents could be observed in average cell. The frequency of abnormal cells were16%～50%. Some multivalentchromosomes and Lagging chromosomes were found in YLP-1,YLP-13,YLP-16whichindicated these materials were translocation lines. YLP were verified generations from distanthybridization.2. Nine lines were selected from hybridization generations between Triticummonococcum and Avena fatua L. for seedling resistance identification, used nine Pucciniastriiformisf. sp. Tritici strains, analysis showed that five lines, YLP-1-4, YLP-7, YLP-9-1,YLP-9-3, YLP-16-1, performed highly resistant to each strain selected, and they weredifferent from gene Yr24/Yr26, therefore, YLP was proved to be a good antigen material toPuccinia striiformisf. sp. Tritici. Genetic analysis of YLP-1-4and YLP-7of resistance tostripe rust, using CRY32, the most toxic epidemic strain in China, showed that the resistanceof YLP-1-4was controlled by a pair of dominant nuclear genes, against YLP-7controlled bya pair of dominant genes and a pair of recessive nuclear genes.3. SSR primers were screened by using bulk segregant analysis (BSA) method, sevenpolymorphic markers linked with dominant stripe rust resistance gene were gotten in YLP-7,Xwmc419, Xbarc187, Xwmc269, Xbarc137, Xwmc216, Xwmc694, Xbarc181respectively,the genetic distances10.2,5.4,3.6,2.4,3.6,4.8,8.4respectively, the location of gene YrYLPwas predicted in chromosome1B near the centromere. The markers Xbarc137and Xwmc216distributed on both sides of YrYLP, and genetic distances2.4cM and3.6cM. These closelylinked SSR markers can be applied to molecular marker-assisted breeding. Test results ofresistance testing and molecular markers of stripe rust resistance genes known located onwheat chromosome1B showed that YrYLP is likely to be a new gene different from theseknown genes. As an excellent stripe rust resistance source material, YLP will have importantvalues in wheat breeding for disease resistance.