脱氧雪腐镰刀菌烯醇(DON)在小麦籽粒中的积累分析

Analysis of deoxynivalenol(DON) accumulation in wheat grains

镰刀菌产生的脱氧雪腐镰刀菌烯醇(deoxynivalenol,DON)污染小麦后对人畜具有较大的毒害作用。为明确DON毒素在小麦籽粒中的积累数量及其与镰刀菌菌株、接菌数量、小麦品种和病害严重度的关系,试验采用单花滴注方法在5个抗病性不同的小麦品种上分别接种9个禾谷镰刀菌菌株,每个菌株接种1×106、1×105和1×104个/mL 3个分生孢子浓度,并利用ELISA法测定收获麦粒中DON毒素含量。结果表明,麦粒中DON毒素含量差异主要是由于不同禾谷镰刀菌菌株产生毒素能力不同所致。接种菌株8003、4020的所有麦粒中DON毒素含量均显著高于相同条件下接种其他7个菌株的小麦。当接种产毒素能力强的菌株时,小麦抗病品种表现出在一定程度上降低DON毒素积累的能力。不同接菌浓度对小麦赤霉病的发病程度和麦粒中DON毒素含量有显著影响,在相同条件下,接菌浓度越高,病害严重度越高,DON毒素含量也越高;反之,接菌浓度越低,病害严重度越低,DON毒素含量也越低。

Contamination of Fusarium deoxynivalenol （DON） mycotoxin in wheat grains is toxic to human and animals. To find out the content of DON accumulation in wheat grains and its relationship with Fusarium isolate, wheat cultivar, inoculating concentration of conidia and severity of wheat scab, nine isolates of F. graminearum clade from different areas were inoculated on five wheat cultivars at the early flowering stage. A method of single flower drip inoculation was applied for each isolate with three concentrations of 10^6, 10^5 and 104 conidia/mL, respectively. DON contents in wheat grains were measured using ELISA test. The resuits showed that the differences in DON content were mainly originated from the capability of producing mycotoxins by different isolates of F. graminearum. Under the same conditions, the DON content was much higher in wheat grains inoculated with the isolates 8003 and 4020 than that with the other seven isolates. While inoculated with the F. graminearum isolates that could produce higher DON mycotoxin, the resistant wheat cultivars displayed a certain extent to reduce the capacity of DON accumulation. The concentration of inoculated conidia had impact on the disease severity of wheat scab in the field and DON content in the grains and showed a positive correlation with either disease severity or DON content.