Composition, Chemotype Diversity Of The Fusarium Graminearum Clade In Shandong And Study On Transferring Hpa99and AtMYB44Genes Into Wheat

Fusarium head blight (FHB) caused by Fusarium graminearum species complex (Fg complex) is among the most destructive and economically important diseases of wheat. To analyze the composition of the Fusarium graminearum species complex in main areas of wheat production in Shandong province, wheat spikes showing FHB symptoms were collected from11cities in2010and2011. Seventy two strains were isolated from these infected spikes and they were selected to analyze the distribution of F. graminearum complex and chemotypes in different geographic areas. The results are as follows:1. The isolates were characterized at the species level by a competition PCR among members of the F. graminearum clade. The results showed that in all regions F. graminearum (95.8%) was the predominant species causing Fusarium head blight (FHB) on wheat in Shandong, while in some cities also F. avenaceum (2.78%), F. meridionale(1.39%).2. We determined their chemotypes using previously described polymerase chain reaction (PCR). The results showed that among the72isolates,70produce DON mycotoxins (97.2%), and1(SF05-5) is NIV chemotyes (1.39%). In addition,1isolate (SF05-4) produces DON and NIV chemotypes. Among the70DON isolates,3were3-acettyldeoxynivalenol (3-AcDON)(4.29%) and67were15-acettyldeoxynivalenol (15-AcDON)(95.71%), F. graminearum isolates from these sampling sites were all the15-AcDON producers.3. The pathogenicity of30isolates was tested at anthesis. The results suggested that isolates were diferent in virulence. F. graminearum showed significantly more aggressive than F. meridionale, otherwise F. graminearum and F. avenaceum showed similar levels of aggressiveness toward wheat. The twenty-four isolates of F. graminearum produced15-AcDON chemotype were more apparent differentiation, strong virulent strains and weak virulent strains were quite. The only isolate SF05-5of NIV and SF05-4produced DON and NIV showed similar levels of aggressiveness, medium pathogenic.4. Single flower drip inoculation experiments were carried out in fields for the sake of testing different wheat varieties in FHB resitiance. The results showed that Tainongl8, Zimai12and Zhouyuan9369were ideal resistant varieties, otherwise Lumai23, Aikang58and Linmai4were sensitive varieties.5. The particle bombardment-mediated transgenic method with AF234296-44vector containing AtMYB44gene and hpa99gene was transferred into Yangmail58and Shannong15, common wheat varieties. The transformated plants were identified to be positive by CPR and PCR tests in To generation. The transformation frequencies were0.306%and0.108%.