中国温室黄瓜灰霉病对啶酰菌胺的抗药性

摘要

Gray mold caused by Botrytis cinerea is a major disease of greenhouse cucumbers and its control is largely dependent on the succinate dehydrogenase inhibitor boscalid. In this study, gray mold-infected cucumbers were collected from greenhouses located in 11 towns in which boscalid had been used, and 163 B. cinerea strains were isolated by single-spore method. The EC50 value effective concentration that could inhibit conidia germination by 50％ compared with the control for sensitive isolates ranged from 0.045 μg/mL to 50.148 μg/mL in the assays. Additionally, 101 isolates were resistant to boscalid, and the resistance frequency ranged from 33.33％ to 86.67％ in these towns. Most of the resistant isolates showed a low or moderately resistant phenotype, with the resistance frequency of moderately resistant isolates being as high as 80％. The SdhB gene harbored a single mutation corresponding to His272. The fitness evaluation showed that the hyphal growth, sporulation, germinability and pathogenicity were different among the resistant and sensitive isolates. The results suggested that dual resistance to boscalid in B. cinerea populations could result in failure to control gray mold.%由Botrytis cinerea引起的灰霉病是温室黄瓜生产上的主要病害,该病害的防治主要依赖琥珀酸脱氢酶抑制剂啶酰菌胺.本研究中,采集了11个乡镇的温室黄瓜灰霉菌标本,采用单孢分离法分离了163个菌株.利用分生孢子萌发抑制法测定了这些菌株的EC50,其范围为0.045μg/mL to 50.148μg/mL.有101个菌株为抗性菌株,这些地区的抗性频率为33.33％ 到86.67％.大多数菌株表现为低抗或者中抗,其中中抗水平菌株抗性频率最高达到80％.测序分析发现,抗性菌株SDHB基因在His272处发生了点突变.适应性分析发现抗性菌株与敏感性菌株在菌丝生长速率,产孢量,孢子萌发率以及致病性等方面存在差异.结果暗示,灰霉病群体对啶酰菌胺的稳定抗药性可能会导致防治的失败.