Genetic Analysis Of Resistance Genes And The SSR Maker Of Wheat Cv. XiaoYan 6 To Puccinia Striiformis

Genetic analysis of resistance genes and the SSR maker of wheat cv. XiaoYan 6 to Puccinia striiformisWang Dian-boSupervised by Prof. Jing Jinxue(College of Plant Protection,Northwest Sci-Tech University of Agriculture and Forestry, Yangling, Shaanxi, P.R.China 712100)Stripe rust of wheat, caused by Puccinia striiformis West. 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 a cultivar breakdown in several years because of cultivars single and resistance gene overcomed by new pathogen. So the research of cultivars resistance received more and more closed attention. Researchers are trying to find means of overcoming cultivars "breakdown" from inheritance mechanisms.High-temperature resistance is a durable,non-racespecific,all stages resistance in a relative high temperature, it is becoming more focus for many researchers. Study on the genetic mechanisms of high temperature resistance gene, it is more important to utilize the high-temperature resistance gene.Xiaoyan6 is the famous variety developed using exogenous genes in 80's of last century by China. It has been grown over 20 years with its high quality resistant disease and resistant adversity, and has been confirmed a durable,high-temperature resistance cultivar, and showed a great application value. This article are to determine the number gene controlling high-temperature resistance and normal-temperature resistance in XiaoYan6, and heritable of the genes in high-temperature and normal-temperature, and to determine the relationships between the high-temperature resistance and normal-temperature resistance, inoculated with race CY31,CY30,CY29-mut3,CY28,which race CY31,CY30 is virulence to XiaoYan6 in normal temperature and avirulence in high temperature, race CY29-mut3,CY28 is avirulence in normal temperature and high temperature.1. To determine the high-temperature gene number and heritability of high-temperature resistance and the relationship of high-temperature resistance to seedling resistance, reciprocal crosses were made among XianYan6 and MingXian169. Parents and F1, F2, F3 progeny from all crosses were tested in controlling temperature(20℃±1) inoculated with race CY31, CY30, CY29-mut3, CY28. IT data were analyzed to determine the number of genes in the cultivar. Two high-temperature resistance genes were detected in XiaoYan6, when tested with CY31, one dominant gene and one recessive gene were detected in XiaoYan6, and had a complementary or a suppressor gene; in test with CY30, two recessive genes were detected, and two complementary recessive genes for resistance; when tested with CY29-mut, CY28, a recessive gene was detected except for a dominant gene which was expressed in normal temperature.The F3 data indicated that the result from F2 were correct, high temperature induce different resistance gene to express.2. In the normal temperature(14℃±1), Parents and F1, F2, progeny from all crosses were tested with race CY29-mut3, CY28 in seedling, a dominant gene was detected in XiaoYan6.To determine the chromosomic location of a gene, material of monosomic Chinese Spring was applied, XiaoYan6 was crossed with a set of susceptible Chinese Spring monosomic. F2 seeds were obtained from self-pollinated monosomic F1 palnts. Seedlings of F2 plants were inoculated with CY29-mut3, CY27, respectively. The results showed that the normal-temperature resistance gene was located on chromosome 4B.In term of the result of monosomic location, SSR maker was applied. A F2 population was developed from the cross of Chinese Spring somic/XiaoYan6 to identify the maker linked with gene YrXY. One maker Xgwm107 linked to gene YrXY was screened by combining SSR molecular maker with BSA (bulked segregation analysis) method. The YrXY gene was mapped on the long arm of 5 chromosome. The genetic distance of Xgwm107 to YrXY was 7.08 cM by mapmaker/EXP3.0 analysis.High-temperature resistance of cultivar XiaoYan6 has va...