Wheat Varieties Resistance To Evaluation And Molecular Mapping Of Fusarium Head Blight And Don Toxin Accumulation

Wheat Fusarium head blight (FHB), also called scab, caused by Fusarium.graminearum Schw., is a worldwide destructive disease of wheat in the warm, semi-humid or humid regions, especially serious in China. The disease not only causes significant losses in yield and reduces grain quanlity, but also induces toxin to contaminated seeds, which is harmful to the healthy of human and livestocks. Fungicides and agronomic techniques have been used for controling FHB, however, they are partly effective to the diseases and cost a lot. Fungicides also causes environmental pollution. Growing FHB resistant wheat cultivars will most likely be one of the most effective measures to control the disease.In order to identify the resistance to FHB of wheat varieties and their interactions with different isolates and inoculation methods in Chinese wheat breeding program, twelve wheat varieties were inoculated with two isolates of Fusarium graminearum and two inoculation methods of spore spraying and single floret injection. ANOVA showed that the effect were significant for method of inoculation, isolates of Fusarium, and genotype. Method of inoculation was with the highest effect among three factors. Wangshuibai possessed the highest and stable resistance to FHB in the experiment of different isolates and inoculation methods, Sumai 3 showed the second highest resistance to FHB and was with less partial scabbed spiklet (PSS) during the experiment than that of other resistant varieties Nobeokabouzu, Fanshanxiaomai and Fan60096. The speed of disease spread was different among resistance varieties, moderate resistance varieties and susceptible varieties; Wangshuibai possessed the lowest speed of disease spread whereas Fan60096 showed highest speed. After inoculated by single floret injection, DON content of different vaiety showed significantly difference. Fan60096 possessed the highest resistance to DON accumulation in the experiment, Wangshuibai showed the second highest resistance to DON accumulation; DON contents of Sumai 3 and Fanshanxiaomai were only lower than that of Frontana, Ningmai 6 and Annong8455. Besides, different type resistancesand their relations were also discussed in the paper.A RILs population containing 118 lines was developed from the cross Annong8455xWangshuibai through the method SSD. AFLP and SSR Markers have been used for screening the polymorphisms between the parents. 174 polimorphic bands among them were employed for analyse of correlation and regression betweem molecular markers and the data of proportional scabbed spiklets and DON accumulation. We found 10 markers linked to Type II resistance to FHB and 4 markers linked to resistance of DON accumulation. Using MapManageQTX20, two major QTLs effect associated with spread resistance to FHB were detected and located on chromosome 2A and 3B, which explained 11% and 23% of phenotypic variance, respectively. Two QTLs associated with the resistance of DON accumulation was detected and located on chromosome 2A and 5A, which explained 4% of the DON accumulated phenotypic variance, respectively.