2018年湖北省小麦赤霉菌群体组成及杀菌剂敏感性检测

 由小麦赤霉菌(Fusarium spp.)引起的小麦赤霉病是小麦生产中最主要的病害之一,严重影响小麦的产量和品质。为明确目前湖北省小麦赤霉菌种群的组成、毒素化学型的分布及对杀菌剂的敏感性现状,本研究于2018年采集分离了96株小麦赤霉菌菌株,经TEF1-α基因鉴定,78株为Fusarium asiaticum,18株为F. graminearum,表明湖北省小麦赤霉菌的优势群体为F. asiaticum;利用特异性片段扩增法鉴定了菌株的毒素化学型,结果表明湖北省小麦赤霉菌菌株以3A DON化学型为主,占供试菌株群体的58%,其次为15A DON,占32%,NIV化学型最少,占10%。采用区分浓度法共检测到2株对多菌灵产生抗药性的菌株,均为F. asiaticum菌株。采用菌丝生长速率法,测定了Fusarium spp.对戊唑醇的有效抑制中浓度(EC₅₀),平均值为(0.66± 0.29)μg·mL^-1,其敏感性已经下降;其中,F. asiaticum与F. graminearum对戊唑醇的EC₅₀均值分别为(0.77± 0.26)μg·mL^-1和(0.35 ± 0.08)μg·mL^-1,表明F. graminearum群体对戊唑醇更敏感。

Population composition and fungicide sensitivities of Fusarium spp. in Hubei Pro-vince in 2018

Fusarium Head Blight caused by Fusarium spp. is one of the most important diseases in wheat production, which seriously affected the yield and quality. In order to explore the composition of the pathogen po-pulations, trichothecenes chemotypes, and fungicide sensitivities of Fusarium spp. in Hubei province in the current state, 96 Fusarium spp. isolates were collected and isolated in 2018. Seventy-eight Fusarium asiaticum and 18 F. graminearum isolates were identified by TEF1-α gene sequence, which indicated that F. asiaticum was the predominant population. Trichothecenes chemotypes of Fusarium spp. was determined by specific fragment amplification method, the data showed that 3A DON chemotype was the predominant chemotype (58%), followed by 15A DON chemotype (32%), and NIV chemotype (10%). A total of 2 carbendazim resistant isolates, both of F. asiaticum isolates, were detected by discriminatory concentration of 5 μg·mL^-1. The tebuconazole sensitivity of Fusarium spp. isolates were determined by mycelium growth rate, the results showed that the mean EC₅₀ values of Fusarium spp. was(0.66± 0.29)μg·mL^-1, the mean EC₅₀ values of F. asiaticum and F. graminearum were(0.77± 0.26)μg·mL^-1 and(0.35± 0.08)μg·mL^-1 respectively, this result indicated F. graminearum was more sensitive to tebuconazole.