College of Advanced Agricultural Sciences, Zhejiang A&F University, Lin'an Hangzhou 311300, PR China.
College of Advanced Agricultural Sciences, Zhejiang A&F University, Lin'an Hangzhou 311300, PR China.
Pestic Biochem Physiol. 2024 Nov;205:106128. doi: 10.1016/j.pestbp.2024.106128. Epub 2024 Sep 13.
Gray mold caused by Botrytis spp. is a common disease on various hosts, including strawberries. In this study, we obtained 59 Botrytis isolates from strawberries from greenhouses in Zhejiang Province, China. Identification of the sampled isolates at species level was performed by a duplex PCR assay method, the result showed that, in Zhejiang, gray mold on strawberry fruits is caused by a complex of Botrytis groups including B. cinerea group N (47.5 %) and B. cinerea group S (52.5 %). The sensitivities of all Botrytis isolates to pyrimethanil were determined based on discriminatory dose method on L-asparagine-based agar medium plate. Our results showed that the isolates obtained from the greenhouses with continuous use of pyrimethanil developed severe resistance to pyrimethanil, and the resistance frequencies of B. cinerea group N and group S isolates were 89.3 % and 41.9 %, respectively. By sequencing, four different resistance-related point mutations were identified in 38 Botrytis isolates: Bcpos5 (16 isolates, 42.1 %), Bcpos5 (14 isolates, 36.8 %), Bcmdl1 (2 isolates, 5.3 %), and Bcpos5⸱Bcmdl1 (1 isolate, 2.6 %). The exogenous addition of methionine could not completely alter the resistance of Botrytis isolates to pyrimethanil. In this study, the pyrimethanil resistance in Botrytis isolates was steadily inherited, and compared to the pyrimethanil-sensitive isolates, the resistant mutants exhibited good fitness in sporulation capacity, spore germination rate, and virulence on strawberries. In conclusion, our results provided a description of the genetic structure of Botrytis groups complex on strawberry fruits and reminded growers to focus on the stable pyrimethanil resistance in Botrytis isolates, caused by point mutations in BcPos5 and BcMdl1.
由 Botrytis 属引起的灰霉病是各种宿主（包括草莓）上的一种常见疾病。在本研究中，我们从中国浙江省温室中的草莓中获得了 59 株 Botrytis 分离株。通过双 PCR 检测方法对采样分离株进行种水平鉴定，结果表明，在浙江，草莓果实上的灰霉病是由包括 B. cinerea 组 N（47.5%）和 B. cinerea 组 S（52.5%）在内的 Botrytis 群体组成的复杂体引起的。根据基于 L-天冬酰胺的琼脂平板上的区分剂量法，确定了所有 Botrytis 分离株对嘧啶胺的敏感性。我们的结果表明，从连续使用嘧啶胺的温室中获得的分离株对嘧啶胺产生了严重的抗性，B. cinerea 组 N 和组 S 分离株的抗性频率分别为 89.3%和 41.9%。通过测序，在 38 株 Botrytis 分离株中鉴定出了 4 种不同的与抗性相关的点突变：Bcpos5（16 株，42.1%）、Bcpos5（14 株，36.8%）、Bcmdl1（2 株，5.3%）和 Bcpos5 ⸱Bcmdl1（1 株，2.6%）。外源性添加蛋氨酸并不能完全改变 Botrytis 分离株对嘧啶胺的抗性。在本研究中，Botrytis 分离株的嘧啶胺抗性稳定遗传，与嘧啶胺敏感分离株相比，抗性突变体能更好地保持在草莓上的产孢能力、孢子萌发率和致病性。综上所述，我们的研究结果提供了对草莓果实上 Botrytis 群体复杂的遗传结构的描述，并提醒种植者注意由 BcPos5 和 BcMdl1 点突变引起的 Botrytis 分离株中稳定的嘧啶胺抗性。
