Studies On The Characteristics Of Resistance Of Durable Resistance Wheat Cultivars To Stripe Rust And Preliminary Exploration Of SSR Marker On Resistance Gene Of N.Strampelli

Ten winter wheat varieties which have different resistance to stripe rust were selected as the material in this study. In Tianshui, which is regard as one of the stripe rust aberrance with high frequency, the research of wheat characteristics infected strip rust during wheat adult plant stage was conducted. The infection type, severity, final severity, incidence, disease index, area under disease progress curve, the relative area under disease progress curve were compared with by investigation in 2003-2005. In order to detect the mechanism of durable resistant wheat cultivars to strip rust, the output, kernel weight, grains per spike, available spike lets per spike ratio, flour yield and protein content were explored, too. At the same time, chosen the hybrid combination of N.Strampelli×Huixianhong, 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:N.Strampelli, Libellula, Wudubaijian and Xiannong 4 show a slow disease development and low final severity, low final incidence. Other varieties had a fast increasing period, final severity, final incidence and disease index all achieved the maximum value. N.Strampelli, Libellula and Wudubaijian displayed a more stable low infection type, low severity and low incidence. These are durable resistance wheat cultivars to stripe rust. Xiannong 4 is a tolerance varieties. There are little variation among 2003, 2004 and 2005. The severity and the incidence were stable between 2003 and 2004, and rose in 2005. Correlation coefficient between relative area under disease progress curve and final severity is 0.98, indicated that we can identify slow rust by investigating final severity directly.After wheat infected by the strip rust-fungus, the output damage ratio and area under disease progress curve become the remarkable correlation. The output loss factor and the weight of a thousand seeds loss factor of susceptible varieties high the resistance varieties. Grains per spike and available spike lets per spike ratio cannot take the wheat anti- strip rust the identification Indexes. After wheat infected by the strip rust-fungus, the flour yield has dropped, protein content has risen.The F1 progenies of N.Strampelli×Huixianhong have 33 plants, there are all resistance to stripe rust. There are 148 plant in its F2 progenies, which ratio of resistance and susceptible is 9:7 corresponding with the heredity rules of two pairs of dominant resistance genes(χ2=1.07,P>0.900). But whether the resistance genes controlled by minor genes, and how are the relations between dominant genes and recessive genes are need to more analysis and identify. The amplication product of the primer WMC25 shows differences between the resistance pool and susceptible pool, but it didn't shows linked to the resistance gene. More researches are needed to find the resistance genes of N.Strampelli.