由灰葡萄孢(Botrytis cinerea Pers.)引起的草莓灰霉病是草莓上危害严重的病害之一。为了解北京地区草莓灰霉病菌对二甲酰亚胺类常用杀菌剂异菌脲的抗性,本研究采用最低抑制浓度法分别检测了2013年和2014年从北京地区15个草莓园采集的共计121株草莓灰霉病菌对异菌脲的抗性。结果表明,北京地区草莓灰霉病菌对异菌脲存在较高的抗性频率,2014年较2013年的抗性频率略有上升,由40.4%上升为45.3%。不同草莓园菌株的抗性频率差异很大,可能与用药水平有关。2014年的低抗、中抗和高抗菌株数分别占检测菌株总数的9.4%、28.1%和7.8%。利用 PCR 技术扩增编码组氨酸激酶基因 BcOS 1中与二甲酰亚胺抗性相关的区段,对抗性菌株的分子机制进行了初步研究,结果表明 BcOS 1基因第1214位核苷酸发生了2类突变：以第Ⅰ类为主,菌株的抗性水平为中抗和高抗,由 ATC 突变为 AGC,导致第365位氨基酸由异亮氨酸变为丝氨酸；第Ⅱ类菌株为低抗,由 ATC 突变AAC,导致第365位氨基酸由异亮氨酸变为天冬酰胺。%The grey mold caused by Botrytis cinerea Pers.is one of the most destructive diseases in strawberry.In this study,a total of 121 B .cinerea isolates collected from 1 5 strawberry gardens in Beijing during 2013 and 2014 were tested for their resistance to iprodione by MIC.The results indicated that the frequency of iprodione-resist-ance of the isolates from Beijing was higher and reached 45.3% in 2014 compared with 40.4% in 2013.The fre-quency of iprodione-resistance of the isolates was obviously different in different strawberry gardens and it might be related with the fungicide usage.The proportion of low-,middle-and high-resistant isolates in tested isolates collected in 2014 was 9.4%,28.1% and 7.8%,respectively.Iprodione-resistant molecular mechanism of the iso-lates was primarily studied by amplifying gene BcOS 1 encoding histidine kinase using PCR.The results showed that two types of mutation occurring at position 1 214 of gene BcOS 1 nucleotide sequence were found:one was ATC→AGC,leading to mutation from 3 6 5 Ile to Ser,and the resistance level of the isolates was middle and high;the oth-er was ATC →AAC,leading to mutation from 365 Ile to Asn,and the resistance level of the isolates was low and high.
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