Molecular Markers For Resistant Gene Of The Durable Resistance Wheat Cultivar-Libellula To Wheat Stripe Rust (Puccinia Striiformis F.sp.tritici West.)

Wheat stripe rust,caused by Puccinia striiformis f.sp.tritici West.,is one of most serious diseases on wheat in all the wheat growing areas in the world,especially in China.Aplication of cultivars resistance is the most important method of controlling stripe rust of wheat.But in several years cultivars breakdown because of single cultivars and resistance gene overcomed by new pathogen.Above all,the discovery of Stripe rust resistance gene is essential for the wheat production and the whole foods' security.Chosen the hybrid combination of Mingxian169×Libellula,the resistance to stripe rust in its F₁ and F₂ progenies were identified.Establishing the resistance pool and susceptible pool with the most resistance and the most susceptible plant in F₂ progenies, and using BSA method to analysis SSR markers and to find the markers linked to resistance genes.All of these were looking forward to offer a theory index to identify durable resistant cultivars molecular mark assistance breeding.The main results as follows:1.In the F₂ population derived from the cross Mingxian169×Libellula,an 23 (resistant):87(susceptible) segregation was observed.The proportion tested by x²-test fitted the expected 3:13 ratio(x²=0.34,p＞0.50),from which we can deduct the resistence of Libellula been contrlled by the interactivity between a pair of dominent and recessive gene.2.The improvement of SSR system:After optimize the SSR amplification system,a set of PCR system was obtained,which was fit for our lab and had a good repeat ability. They are templet DNA＜0.5μg,10×Taq Buffer(20mmol/L MgCl₂) 2.5μl, 2.5mmol/LdNTPs 2.0μl,10μmol/L Primer 1.0μl(the last concentration was 0.5μmol/L), 2.5U/μl Taq 0.5μl,the total reaction system is 25μl.The conditions of cycles were pre-denaturation(95℃,4min),denaturatio(94℃,50s),annealing(50s),and elongatio (72℃,50s) after 30 cycles,which woμld continue to elong about 10 min at 72℃.3.Based on the result of Bulked segregation analysis(BSA),the gene for resistance to stripe rust was located on 1BS in the near Xgwm18,and was designated Yr-Liu temporarily.While due to the drought and high seedling death ratio,the location of Stripe rust resistance gene Yr-liu can only be identified near the Xgwm18 which needs further investigation.