Discovery And Molecular Mapping Of Two Novel Genes YrTp1 & YrTp2 Conferring Resistance To Wheat Stripe Rust

Stripe rust (Puccinia striiformis Westend f. sp. tritici), caused by Puccinia strriformis Westend f. sp. tritici Eriks is one of the most important disease of wheat (Triticum aestivum L.), which resulted in massive wheat yield loss in several epidemics in China. Loss of variety resistance to stripe rust pathogene is an important factor causing massive periodical epidemic of stripe rust in wheat production. Using resistant varieties is the most economic, effective and environment-friend method. Emergency and development of new races of stripe rust pathogene have led widely planted varieties into serious crisis of resistance losing. Currently, only very few genes, such as Yr5,Yr10,keep immune or highly resistant to high frequency virulent races CY30, CY31 and CY32, among which the main preponderant race CY32 has led major varieties into susceptible in China because of its wider virulence array and higher autoecious fitness. It has affected 90% of planting area. CY32 was virulent to Yr1,Yr2,Yr3,Yr4,Yr6,Yr9,Yr15,Yr27,YrA,Yralba,YrCle,YrCV,YrGaby,YrRes,YrSD,YrSpP,YrSO as well as most varieties and resistance resources used in production. Utilizing alien resistant resources was a powerful breeding mean for stripe rust resistance. After Yr9 derived from Secale cereale L. had taken a very important role in production for nearly 20 years, Zhong 4 derived from Triticum aestivum×Thinopyrum intermedium has become the main resistant resource for stripe rust resistance breeding all over the world. As there were only very few resistant resources in use currently, in order to avoid disaster loss of variety resistance like 1BL/1RS translocation and Fan 6 because of simplification of resistance resources it is in urgent need to search new resistant resources, especially to unlocking effective novel resistant genes from wheat relative species and genus.Molecular markers could facilitate the identification and location of novel genes. As so far, among 15 Yr genes, 10 Yr genes were linked with SSR markers.Twenty lines with resistance and good agronomic traits were screened out in 125 lines derived from T. aestivum×Th. Ponticum, most of which were immune and 2-3 were high resistant including one late-slow-rusting line. A line A-3 immune to current epidemic yellow rust races (CY29, CY30, CY31, CY32) was screened out in offspring of T. aestivum×Th. ponticum. Previous GISH analysis did not detect any...