| Wheat stripe rust was one of the most major disease in wheat worldwide, seriously threatening the food security of our country. Planting resistant cultivars was the most economical, effective, and environment-friendly way to control the disease. Since wheat stripe rust showed highly parasitic specificity and variability, a new variation can overcome the resistance of wheat cultivars. Hence, it was of vital importance that searching for new resistance materials in breeding for disease resistance and identifying resistances of stripe rust in current wheat cultivars from epidemic regions in china. The implementation of different genetic background of wheat materials and resistance genes could make the variation of rust races slow down, and it also made the time of application longer. It was very meaningful to control stripe rust by using the new resistance gene to breed new disease-resistant varieties. Making the resistant genetic diversity of wheat varieties richful was the aim of resistance breeding, and looking for new resistance genes was the main purpose of filtering the resistance materials. The steps of discovery and application of resistance materials included collection, identification, screening, analysis, commercial breeding parent varieties and reasonable layout.Wheat resistance varieties, wheat advanced lines, wheat variety Friedrichswerther and P9936 were evaluated for the presence resistance in a field with two types of disease nursery respectively: the artificial nursery inoculated with two prevalent races(CYR32 and CYR33) in Yangling, Shaanxi Province and a natural infection of Pst in Tianshui, Gansu Province. Meanwhile, the seedlings of the cultivars were inoculated with the five races CYR23, CYR31, CYR32, CYR33 and CH42 in the greenhouse respectively. The resistance genes were postulated using molecular markers for Yr5, Yr9, Yr10, Yr15, Yr17, Yr18 and Yr26 in combination with resistance spectra. Germination drought stress experiment of wheat advanced lines was used to evaluate its drought resistance.The agronomic traits of wheat advanced lines were also investigated and evaluated. In addition, Genetic groups F1, F2 and F3 of wheat varieties Friedrichswerther and P9936 were established to make its disease-resistant genetic mechanisms clear.The experimental results were as follows:1. The results suggested that under the guidance of good disease resistance, drought tolerance and synthetical properties breeding goal, Zhengmai 9023 and Lan Chao 906 were used as gene accumulation capacity, combining pedigree selection method with molecular markers to assist selection breeding in order to improve and innovate variety Zhengmai 9023 and Lan Chao 906. We obtained the F8-1-2, F8-1-3, F8-2-2, F8-2-3, F8-2-4, F8-5-1, F8-5-2, F8-5-4, F8-6-1, F8-6-2, F8-6-3 and F8-6-4 out of 20 wheat advanced lines in the experiment with good disease resistance, drought resistance and comprehensive characters, witch could be used as parent resistance material.2. There were 53 samples with new and stable resistance genes were selected from more than 330 collected wheat materials.Among them, Zhengmai 958, Xinong 389, FENMAN, Baidatou and Mianyang 1275-1were 5 all stage resistance wheat materials; all the 45 resistance wheat materials including Zhoumai17 were the type APRI while Lin Y867, Bouquet and Frontana were the type APRII.The use of these wheat materials with new and stable rust resistance genes would be the focus of resistance breeding.3. Wheat variety Friedrichswerther and P9936 showed adult-plant resistance at both artifical nusery with mixed races at Yangling and natural nersery at Tianshui, which suggested that both of them were typical adult disease-resistant materials. Genetic groups F1, F2 and F3 of wheat varieties Friedrichswerther and P9936 were established to make its disease-resistant genetic mechanisms clear. In addition, the result of molecular detection suggested that wheat variety Friedrichswerther and P9936 carried a pair of unknown dominant resistance genes which determing their disease-resistant ability.In this study, the selection and evaluation of the resistance materials was aim to make a better use of the source resistance. The focus of the next research was to discover new resistance genes and their closed molecular markers using the genetic analysis and molecular mapping of resistance genes and to choose the main variety of adapted to local environment as the parents according to the type of resistance, Yr genes of the resistance materials and the characteristics of wheat stripe rust area popular, and to combine the materials with different resistance genes layout to breed area adaptive disease-resistant breeding parent by cross and backcross and connecting with the molecular detection, then we could made good disease resistance genes play a real role in wheat breeding. |
PDF Full Text Request