Genetic Mechanism Of Resistance To Stripe Rust Of Wheat Cultivar Xiao Yan 6 In The High Temperture

Stripe rust of wheat, caused by Puccinia striiformis f. sp. tritici, is one of most serious disease in the world. Aplication of cultivars resistance is the most important method of controlling stripe rust of wheat. But in several years cultivars breakdown because of single cultivars and resistance gene overcomed by new pathogen. So the research of cultivars resistance paid closed attention. Researchers are trying to find means of overcoming cultivars"breakdown"from inheritance mechanisms.Xiaoyan6,which developed by using exogenous genes from Elytrigia elongata at the end of 70's last century, is a famous variety that has high-temperature resistance to stripe rust. Inheritance of stripe rust resistance gene in xiaoyan6 is important for revealing mechanism of resistance to stripe rust and developing durable cultivar. By genetic analysis, monosomic analysis and the SSR technique, the result showed as follows:1. In controlling temperature(20~22℃), seedlings of Xiaoyan 6, Mingxian 169 and their F2 progeny were tested with China races (CY29-mut3,CY30,CY31,CY32 and Su-4) of Puccinia striiform f.sp.tritici. The results indicated that one dominant gene and one recessive gene confer resistance to CY29-mut3, CY31 and Su-4, two complementary dominant genes to CY30 and CY32 in Xiao yan6.2. To determine the chromosomic location of genes, material of monosomic Chinese Spring was applied, XiaoYan6 was crossed with Ming xian169 and F3 lines were obtained from self-pollinated monosomic F2 plants. Seedlings of F3 lines were inoculated with CY29-mut3. The results showed that two high-temperature resistance genes were located on 4B and 5A chromosomes.3. In term of 121 primers of SSR maker, F3 lines were developed from the cross of XiaoYan6 and Ming xian169 to identify the maker linked with gene Yrhxy. One maker Xgwm304 linked to gene Yrhxy was screened by combining SSR molecular maker with BSA (bulked segregation analysis) method. The Yrhxy gene was mapped on the short arm of 5A chromosome. The genetic distance of Xgwm304 to Yrhxy was 17.05cM by mapmaker3.0 analysis soft. Resistance stripe rust gene in xiaoyan 6 was located on chromosomes 5AS with classical genetic in high temperature. By chromosome location and molecular markers, the...