| Wheat fusarium head blight (FHB) syn. wheat scab caused by various Fusarium spp. is a worldwide fungal disease, which mainly occurred in the provinces and municipalities of Yangtze River,South China and Northeast areas in China. In recent years, it has expanded to provinces of Yellow River basin, damaged somewhat 1/4 of wheat area. The major pathogenic type in most areas of China is Fusarium graminearum Clade. FHB not only caused the severe loss of grain yield, but also caused grain contamination with several Fusarium mycotoxins, such as Deoxynivalenol (DON), Fumonisin, T-2 and Zearalenone (ZEA) mycotoxins, which is deleterious to the healthiness of mankind and livestocks. At present, the research on mycotoxins is limited in china, especially for study on the DON accumulation in wheat after artificial inoculation with different Fusarium graminearum isolates in the field. The purpose of this study is to detect the contamination and distribution of Fusarium mycotoxins in wheat from different wheat growing areas of China, and to analyze the DON mycotoxin content in wheat grain while inoculated with different concentrations and isolates of Fusarium graminearum on different wheat cultivars, so as to find out the content of DON accumulation in wheat grains and its relationship with Fusarium isolates, wheat cultivars, inoculating concentration of conidoispores and severity of wheat scab.ELISA kits prepared from mycotoxins specific antibodies was employed to determine the content and contamination rate of the DON, Fumonisin, T-2 and ZEA mycotoxins content in 360 wheat cultivars from different wheat growing areas in China.The results showed that the contamination of the Fusarium mycotoxins in wheat grains was widely distributed but low content.The average concentration of the DON mycotoxin was 62.81μg/kg, which was the highest of the four Fusarium mycotoxins. Comparative analysis of the content of the four Fusarium mycotoxins showed that the DON, ZEA and T-2 mycotoxins in different wheat growing areas existed significant differences (P＜0.01), but fumonisin mycotoxin in all the groups were not significant differences (P> 0.05).The contamination rate of T-2 mycotoxin is the hightest of the four mycotoxins, the Fumonisin mycotoxin, DON mycotoxin and ZEA mycotoxin are followed.Nine isolates of F. graminearum Clade from different areas was inoculated on five wheat cultivars at early flowering stage by a method of single flowers drip, each isolate with three concentrations of 106,105 and 104 conidoispores/mL, respectively. The severity of wheat scab were scored based on a 1-4 scale in postinoculation of 21 days, and ELISA method was also employed to determine the DON content in the harvested wheat grains. The results showed that the disease severity of wheat scab was not significantly correlated to the DON content in wheat grains. The difference in DON concentration was mainly ascibed to the capability of producing mycotoxins by different isolates of F. graminearum. Under the same conditions, the DON content in wheat grains when inoculated with the isolates 8003 and 4020 of F. graminearum were much higher than that inoculated with the other seven isolates. While inoculated with the F. graminearum isolates strong to produce DON mycotoxin, the resistant wheat cultivars displayed a certain extent to reduce the capacity of DON accumulation. The concentration of Fusarium conidiospores inoculated could impact on the disease severity of wheat scab in the field and DON content in the grains, which showed a positive correlation either disease severity or DON content. At the same time, it has been also found that the accumulation of DON toxins, Fusarium isolates and wheat cultivars probably exist the cross-interactions.This results above-mentioned would provide useful aids to the screen of wheat resistance cultivars, mechanism of resistance in wheat, and mechanism and control of producing Fusarium mycotoxins in the pathogen, and so on. |
PDF Full Text Request