Genetic Analysis And Molecular Marker Of New Wheat Germplasm "98-199" Resistance Stripe Rust

Wheat Stripe (Yellow) Rust is one of the most serious diseases in wheat production in China. 98-199 is a new germplasm with resistance gene against stripe rust in wheat. In this study, Random Amplified Polymorphic DNA (RAPD) and Bulked Segregate Ananlysis (BSA) were employed to detect molecular markers linked to stipe rust resistance gene in wheat germplasm 98-199.The main results were as following:1. By inoculating with CY32 which is the most popular race of wheat stripe rust, the stripe rust resistance test was performed for F₂ 148 variant plants from the hybrid of susceptible variety Xinong2302 and resistance strain 98-199. The results showed that 113 plants were resistant and 35 plants were susceptible, ( x₀²=0.144< x_0.05.1 ² = 3.84), indicating that segregation proportion of resistance plants to susceptible plants conformed to 3:1, and that the resistance of 98-199 to stripe rust was controlled by dominant gene.2. Resistance DNA pool and susceptible DNA pool were established according to BSA. By PARD analysis, nine primers which amplified polymorphic DNA fragments in parents and segregation population were screened from 314 10-base random primers. Among them only one primer S214 (GGTGATCAGG) could amplify the additional DNA fragments (about 1260bp) in the resistant parent 98-199 and resistant DNA pool. The results were the same in 3 repeats. The molecular marker linked to stripe rust resistance gene in 98-199 was primarily named S124₁₂₆₀. The genetic linkage of the additional DNA fragment amplified by the primer S124 with the stripe rust resistance gene in 98-199 was tested on segregating F₂ population (148 plants). Among 113 resistant plants, 102 plants carried the marker S2142160, while other 11 resistant plants and 35 susceptible plant s were lack of this marker. Calculation result showed that the genetic distance between the marker and stripe rust resistance gene in 98-199 was about 7.46±2.26cM. The molecular marker (S124₁₂₆₀) was a RAPD marker linked to stripe rust resistance gene in 98-199.3. Resistant germplasms and susceptible germplasms F₂ from the hybries of 98-199 × Mianyang26, 98-199 × 98-68, were tested by the primer S124. The results showed that the marker S124₁₂₆₀ linked to not only the stripe rust resistance gene in 98-199, but also the hybrid generations with the resistance gene. It indicated that the marker can be validly employed in Marker-assisted selection (MAS).4. While the original parents of 98-199, Guinong 21, Sumai3, C39, were tested with primer S214, the marker S214₂₁₆₀ existed in Guinong 21, but did not found in other parent materials. It showed Guinong 21 maybe carry the same stripe rust resistance gene as that in 98-199.