Development Of Wheat New Germplasm With Stripe Rust Resistance And Base Of Its Molecular Cytogenetics

Stripe rust, caused by puccinia striiformis West.f.sp.tritici, is an important disease of wheat (Triticum aestivum L.) in many regions in the world. In China, the serious economic losses were occurred because of seven large-scale outbreaks and many moderate, and small-scale epidemic of wheat stripe rust in last 50 years. For controlling the disease, the application of the resistant cultivars is the most economical and safest method to the environment. However, Cultivars with stripe rust resistance often become susceptible within a new virulent race of the pathogen that circumvents the resistance. Therefore, the development, introduction and identification of new germplasm or gene with strip rust resistance are a long-term strategy. Hundreds of wheat stripe rust resistance cultivars, developed using introduction of Lovrin, has played the important role in stabling wheat production in last 30 years in China. However, more cultivars, used in wheat production now, are susceptible to the new virulent races,which are CY30, CY31, CY32, taibai 4 and shuiyuan11 pathotypes. The toxic analysis indicated that these new virulent races include many kinds of new toxic gene. They not only infect Lovrin wheat (carring gene Yr9) and"fan6"derivatives, but also harm more other wheat cultivars which are used in wheat production now. And their toxic scope is wider. The research indicated that more wheat anti-stripe rust genes which had been located and named have lost the resistance completely to the prevalent virulent races at present. In China, the strip rust anti-source is deficient seriously in wheat production at present. And it is urgently to develop and identify new anti-resource and gene, which can be used directly to open up the wheat hereditary basis of the anti-strip rust. In this study, the new germplasms with stripe rust new virulent races resistance were developed, by transferring gene resistant to stripe rust races from hexaploid triticale into common wheat by cross-fertilization between them as well as multiple back-crossing. And, the mechanism that foreign gene with strip rust resistance was transferred from hexaploid triticale into common wheat was been studied by the method of general genetics and cytogenetics as well as molecular genetics. At the same time, the genetics base of stripe rust resistance new germplasms as well as resistant inheritance property of stripe rust resistance gene have been also studied. The main results are...