Evaluation Of Resistance To Scab Caused By F. Graminearum And QTL Mapping In RILs Of Frontana/Inia66

Fusarium head blight is a devastating disease of wheat production world-wide. It caused by the Fusarium graminearum that cause spikes rot, and is particularly damaging in region with a warm and humid climate. Recently, with change of crop rotation and climate, wheat Scab was extended and aggravated among the areas in China. The most effective strategy for controlling FHB in wheat is through the development of resistant cultivars. The new breeding technology of SSR molecular markers can improve the effeiciency of breeding.In this study, through the SSR molecular markers, we analyse the gene of resistance Scab in wheat. The purpose of this study was to locate the resistance scab gene at Frontana and found the marker which link it. It could establish the theory and technology basic for marker aided selection. Main results were as follows:1. The percentage of the diseased spikelets were 9.5% in the resistant parent Frontana, and 32.31% in the susceptible parent Inia66. The range of the diseased spikelets percentage were 5.63%～57.51% in population, and the mean diseased of spikelets was 28.50%. The genetics resistance had transgressive resistance.2. The percentage of the diseased spiketlets of Frontana/Inia66 RILs showed normal distribution; Through analysis of variance in the RIL population of Frontana/Inia66, the variance was significantly between lines(P<0.0001). This was real genetics variance between lines and RIL population was satisfied with the request of molecular marker mapping.3.Bulked segregate analysis(BSA)was used to establish resistant and susceptible gene pool in order to search for SSR markers with polymorphism. The PCR results amplified by SSR primers of Frontana/Inia66 RIL individuals were analyzed by using Mapmaker3.0 and WinQTLCart2.5. The results indicated that this gene was located on the chromosome 6A.4.The genetic map which included resistant gene to Scab of Frontana and Markers was constructed. This QTL associated with FHB resistance mapped on chromosome 6A, explaining 12.9%of the phenotypic variation. The position is in the Xbarc113～Xbarc1165 interval. The distance between resistant gene and Xbarc113 was only 0.01cM.