Analysis On Durable Resistance To Stripe Rust Of Wheat Cultivars Libellula And Xiannong4

In this research, some important races of stripe rust were used to analyze the durable resistant mechanism of cultivars Libellula and Xiannong4.Resistant spectrum and components at seeding and adult stages, the disease epidemic speed, specialization of resistant components to different races and the inheritance mechanism, and so on, were tested respectively. The results revealed their durable resistant mechanism of biology, epidemic, genetic. The specific results were showed as follows:(1) Fourteen races, such as CY18,CY19,CY21,CY22,CY23,CY25,CY27,CY28, CY29, CY30, CY31,CY32,Su4 and Su14, were used to identify the two cultivars'resistant spectrum at seeding and adult stages respectively, the results showed: At seeding stage, Libellula was moderately–high susceptible to CY21,CY28,CY29,CY31,CY32; It was immunity or moderately resistant to CY18,CY25, and moderately resistant to moderately susceptible to the other races. At adult stage, it was moderately-susceptible to CY29, CY31, CY32 and immunity or moderately resistant to other races. For Xiannong4, it was moderately resistant to susceptible to CY18,CY22,CY25 and susceptible to other races at seeding stage ;and it was moderately resistant to moderately susceptible to CY18,CY22,CY25,CY27 and susceptible to other races at adult stage.(2) The prevalent race CY32 was used to test the two cultivars'resistant components at seeding and adult stages. The results indicated that the resistant components of Libellula, such as latent period, sporulation capacity, period of spore production and density of uredenium, were all obviously different from Xiannong4 and highly susceptible cultivar Huixianhong at seeding stage. The resistant components of Xiannong4 at seeding stage were similar to that of Huixianhong. At adult stage, Libellula'disease index and loss rate of 1000 grains weight were also obviously low to Xiannong4.(3) The disease epidemic rate of Libellula, xiannong4 and huixianhong were 0.0791, 0.1375, 0.1843 respectively, which were different from each other significantly. In field, Libellula could obviously postpone disease prevalence, while Xiannong4 postponed the disease at certain degree.