Molecular Markers Linked To A Resistance Gene Against Stripe Rust (Puccinia Striiformis West. F. Sp. Tritici) In Chinese Native Wheat Variety Hongmai (Jing 2747)

Stripe rust, caused by Puccinia striiformis West. f. sp. tritici is one of the most devastating diseases of wheat throughout the world. Most of the resistant varieties to yellow rust in China are introduced from abroad such as US, Italy, Chile, Rumania, USSR and so on. At the same time, it is useless of Chinese native wheat varieties which are multi-quantity and multi-species in breeding. It may exist resistance gene against stripe rust according to the adaptability.Hongmai (Jing 2747), a Chinese native wheat variety, was resistant to many physiologic races of Puccinia striiformis West. f. sp. tritici from China. In this study, BSA (bulked segregant analysis) and RAPD (randomly amplified polymorphic DNA) methods were used to develop molecular markers linked to the resistance gene in the wheat variety. Results following:1. Genetic analysis indicated that resistance to the physiological race CY19 of the pathogen in the variety was controlled by one dominant gene.2. The resistant and susceptible DNA pools were prepared respectively from the cross between Mingxian 169, a susceptible variety used as female parent, and Hongmai (Jing 2747). Two hundred and thirty-six 10-mer primers were screened in RAPD analysis. A polymorphic DNA fragment of about 242 bp was amplified by the primer S1167 only in resistant DNA pool and Hongmai (Jing 2747), but not in susceptible DNA pool and the susceptible variety Mingxian 169.3. Genetic linkage between the polymorphic DNA fragment S1167₂₄₂ and target gene was tested on 201 F₂ plants from the cross Mingxian 169×Hongmai (Jing 2747). The DNA fragment S1167₂₄₂ was amplified in 156 out of 164 resistant plants, not in 34 out of 37 susceptible plants. The exchange happened in 11 plants in total and the genetic distance was 6.1 cM between S1167₂₄₂ and the target gene.4. After transforming and invalidating we have obtained the sequence of S1167₂₄₂ The RAPD marker S1167₂₄₂ identified in this study showed high repeatability which to be used in marker-assisted selection in wheat breeding program and promote utilization of the resistant gene in Hongmai (Jing 2747).