Fan F, Li N, Li G Q, Luo C X
Key Lab of Horticultural Plant Biology, Ministry of Education, and College of Plant Science and Technology.
College of Plant Science and Technology and the Key Lab of Crop Disease Monitoring & Safety Control in Hubei Province.
Plant Dis. 2016 Dec;100(12):2414-2421. doi: 10.1094/PDIS-03-16-0395-RE. Epub 2016 Oct 5.
During the early summer of 2012 and 2013, samples of gray mold were collected from greenhouse tomato at eight locations in Hubei Province, and 221 isolates of Botrytis cinerea were obtained and evaluated for the sensitivity to fungicides carbendazim, diethofencarb, boscalid, fludioxonil, and cyprodinil. Results showed that isolates with resistance to carbendazim and cyprodinil were widespread, whereas isolates with resistance to carbendazim and diethofencarb were found at only two locations. No isolates with resistance to boscalid or fludioxonil were detected. Altogether, four resistant phenotypes were determined (i.e., CarDieCyp, CarDieCyp, CarDieCyp, and CarDieCyp). Among them, CarDieCyp and CarDieCyp were widely distributed, and there was a dominant resistant phenotype at each location. Interestingly, isolates resistant only to cyprodinil were not obtained because the resistance to cyprodinil was always associated with the resistance to carbendazim, demonstrating that a phenotype of multiple fungicide resistance of B. cinerea was more likely to have evolved from previously resistant subpopulations. Stability of resistance to carbendazim, diethofencarb, and cyprodinil was assessed, and the resistance was stable. Fitness tests showed that, as a group, the carbendazim-resistant isolates were not significantly different from sensitive isolates. However, the mycelial growth and virulence of the carbendazim, diethofencarb, and cyprodinil triple-resistant group were significantly lower than the sensitive group, indicating that the triple-resistant isolates suffered from the disability of colonizing the hosts. It should be noted that there was no significant difference for other fitness components (e.g., sporulation or osmotic sensitivity to NaCl), suggesting that the triple-resistant isolates were still competitive in these traits. To investigate the mechanisms of resistance to carbendazim and diethofencarb, partial β-tubulin genes of 10 carbendazim-resistant isolates and 5 isolates resistant to carbendazim and diethofencarb were sequenced, and all 10 carbendazim-resistant isolates harbored the mutation E198V or E198A. For the 5 isolates resistant to carbendazim and diethofencarb, all of them possessed the mutation E198K, and no other mutations were detected. The location-specific resistance profiles found in this study are crucial in designing proper gray mold management strategies in these areas.
在2012年和2013年的初夏，从湖北省8个地点的温室番茄上采集了灰霉病样本，共获得221株灰葡萄孢分离株，并对其进行了多菌灵、乙霉威、啶酰菌胺、咯菌腈和嘧菌环胺的敏感性评估。结果表明，对多菌灵和嘧菌环胺具有抗性的分离株广泛存在，而对多菌灵和乙霉威具有抗性的分离株仅在两个地点被发现。未检测到对啶酰菌胺或咯菌腈具有抗性的分离株。总共确定了四种抗性表型（即CarDieCyp、CarDieCyp、CarDieCyp和CarDieCyp）。其中，CarDieCyp和CarDieCyp分布广泛，每个地点都有一种占主导地位的抗性表型。有趣的是，未获得仅对嘧菌环胺具有抗性的分离株，因为对嘧菌环胺的抗性总是与对多菌灵的抗性相关，这表明灰葡萄孢的多重抗药性表型更有可能从先前的抗性亚群体进化而来。评估了对多菌灵、乙霉威和嘧菌环胺抗性的稳定性，结果表明抗性是稳定的。适合度测试表明，作为一个群体，抗多菌灵分离株与敏感分离株没有显著差异。然而，多菌灵、乙霉威和嘧菌环胺三重抗性群体的菌丝生长和毒力显著低于敏感群体，这表明三重抗性分离株在定殖宿主方面存在缺陷。需要注意的是，其他适合度成分（如产孢或对NaCl的渗透敏感性）没有显著差异，这表明三重抗性分离株在这些性状上仍具有竞争力。为了研究对多菌灵和乙霉威的抗性机制，对10株抗多菌灵分离株和5株抗多菌灵和乙霉威分离株的部分β-微管蛋白基因进行了测序，所有10株抗多菌灵分离株都含有E198V或E198A突变。对于5株抗多菌灵和乙霉威的分离株，它们都具有E198K突变，未检测到其他突变。本研究中发现的特定地点抗性谱对于在这些地区设计合适的灰霉病管理策略至关重要。
