Sichuan Fusarium Toxin Type Chemical Analysis And Accumulation Regularity Of DON In Wheat Research

Wheat scab(Fusarium head blight), widely distributed in warm, moist areas of the world, the disease can cause serious threat to food security in wheat and other cereal crops.Currently, toxin chemical type of Fusarium graminearum is rarely reported in Sichuan, in addition, wheat materials were inoculated with different types of pathogenic strains of Fusarium spp., and DON content of harvested wheat grain was rarely reported. In this study, we colleted wheat scab-like illness from different redions of Sichuan, isolated and identified these pathogenic species of wheat scab types and the type of chemical toxins, and analyzed the relationship of pathogenic Fusarium graminearum species and chemical type distribution to the geographic origin in Sichuan Province respectively. inoculated different types strains to different resistant wheat varieties, then test the DON content in wheat grain after harvest, in order to reveal the relationship between the incidence, wheat varieties and pathogens of the accumulation of toxins in wheat. The results are as follows:we got 134 Fusarium spp. isolations collected from Sichuan Province 15 City of 71 towns, then we use morphology, molecular identification of pathogenic types,The results show that:two types that Fusarium asiaticum (F. asiaticum) and Fusarium graminearum (F. graminearum) were identified in Sichuan Province, the frequency of F. asiaticum is 76.87%; there are different frequency of pathogenic species in different regions, Chengdu, Suining, Meishan F. graminearum (44.44%?52%) and F. asiaticum (48%?55.56%) roughly the isolation frequency, Mianyang, Ya'an, Nanchong and other places F. asiaticum(71.43%?82.82%) frequency significantly higher than F. graminearum(12.5% ?26.32%), and Neijiang, Bazhong, Guangyuan and other places where F. asiaticum was only be detected,besides there is no direct correlation between the type strains and their geographic origin in Sichuan Province.Specific primers TOXP1/P2 and Tri303F/R, Tri315F/R were used to identify the chemical type of Fusarium spp.. The results shows that:In Sichuan Province the mainly of toxin chemical type of Fusarium spp. is NIV(76.12%), followed by deoxynivalenol (DON), frequency separation 23.88%; F.graminearum detected in 15-AcDON (77.4%) and NIV (22.6%) two chemical type, F.asiaticum detected in 15-AcDON (3.88%),3-AcDON (3.88%) and NIV (92.24%) three chemical type; Acetylated DON species relevant to strains,3-AcDON detected only in F.asiaticum, in Sichuan mainly acetylated DON type is 15-AcDON (87.5%),15-AcDON mainly toxigenic strain is F. graminearum (85.71%); Besides, we detected 15-AcDON and 3-AcDON two toxins types of F. asiaticum strain in Nanchong, however in other areas F. asiaticum strain can only be detected in 15-AcDON or 3-AcDON, proved that Nanchong is the most abundant type of toxin region. In this experiment, we did not find wheat scab pathogen type and geographic origin of toxic chemicals have a direct correlation.Use the isolations that identified as the dominant species, wheat scab pathogen virulent, pathogenic weak all three different types of Fusarium spp. strains and inoculated to five different resistant varieties of wheat, then use ELISA to test the harvested wheat grain of DON content,The results shows that:different strains inoculated wheat have different disease index and DON content, different resistance wheat after inoculated pathogens also have different index and DON content; Virulent strain often stronger toxigenic than pathogenic weak strains, strain virulence strongest 99 (49), after inoculated DON content in wheat grain (548.93?g/kg) higher than other strains, as the advantage of strains 11,22,33 strain that after inoculated disease index of wheat even on a little difference, but in the DON content in wheat also present differences (257.76?g/kg,364.13?g/kg,199.92?g/kg), after weak pathogenic strain was inoculated wheat, wheat field disease index and DON levels were lowest; Susceptible cultivar Mianyang 31 under the same conditions, often in the field disease index (47.53)and grain DON content (492.41 ?g/kg) than high resistant varieties, the disease index of Sumai 3 and Wangshuibai (23.52,18.21), DON grain content (130.69?g/kg,43.85?g/kg) were lower, the difference was not significant in the two wheat.The results showes:Field of Wheat Scab severity and DON content index were impacted with wheat and inoculated with pathogenics, the DON accumulation content of disease-resistant varieties is lower than the susceptible ones, the virulent strain producing more DON than pathogenic weak strains, correlation analysis by SPSS 17.0 showed a significant correlation between disease index both wheat field and DON content.The results relvealed pathogenic species and toxic chemicals type distribution in Sichuan Province and provided a basis for breeding and control of wheat scab.