辣椒疫霉菌对甲霜灵的抗性风险研究

通过对安徽省各地辣椒疫霉菌对甲霜灵抗性进行监测和室内抗性诱导, 结果发现: 野生辣椒疫霉菌株中敏感、中抗和抗性菌株分别占 63.2%、30.4% 和 6.4%, 说明敏感菌株是安徽省辣椒疫霉菌的优势种群, 但 EC50 测定结果表明安徽的辣椒疫霉菌对甲霜灵的敏感性群体水平上已出现不同程度的分化; 室内药剂直接诱变容易获得抗性突变株, 且抗性水平可较其敏感亲本高近 1 000 倍, 说明辣椒疫霉菌对甲霜灵存在较大的抗药性风险, 据此, 讨论了相应的抗药性治理对策。

Resistance risk assessment of Phytophthora capsici to metalaxyl in Anhui province

Resistance of Phytophthora capsici isolates from Anhui province to metalaxyl was investigated. The results showed that the metalaxyl sensitive isolates,metalaxyl tolerant and metalaxyl resistant isolated were 63.2%,30.4% and 6.4%,respectively. It indicated that most of Phytophthora capsici isolates from Anhui were sensitive to metalaxyl,but the EC50 value showed that the sensitivity to metalaxyl has a diverse differentiation among these isolates. Metalaxyl resistant isolates were induced in vitro. It showed that resistant mutants are easy obtained from metalaxyl amended media,and the resistant level was about 1 000 times of that of the sensitive wild-type. These studies indicate that there might be resistance risk to metalaxyl in the isolates of Phytophthora capsici. The strategy of the resistant risk management is discussed in the paper.