Study On Resistance Of Botrytis Cinerea To Two Kinds Of Aspiration Inhibitors Collected From Fruits And Vegetables

Gray mold is one of the global fungal diseases, mostly caused by Botrytis cinerea. The mainaspiration inhibitors to control Gray mold are Qo center inhibitor (QoIs)and the succinatedehydrogenase inhibitor(SDHIs).Shift of sensitivity to azoxystrobin (a Qo center inhibitor, QoI) from2010to2012in B.cinerea collected from strawberry, tomato, eggplant, and grape greenhouses in Zhejiang provincewas monitored by the method of mycelial growth rate. The results showed that a significantlyincreased tendency of the percentage of the low sensitivity subgroups of B. cinerea. Thepercentage of isolates with EC50＞5mg/L was12.5%,15.8%, and28.3%, respectively. Themean factor values for the impact of alternative respiration on sensitivity to azoxystrobin were2.91±0.89and5.72±2.82during mycelial growth and during spore germination. And, there wasno significant difference in mycelial growth, sporulation, sclerotial production, and pathogenicitybetween azoxystrobin resistant and sensitive isolates.Further research indicated that there weretwo type of cyt b gene in B. cinerea. The type I isolates have introns closely followed the codon143in cyt b gene and the type II isolates have no introns closely followed the codon143in cyt bgene. Most of B. cinerea isolates belong to the type II. All the type I isolates were azoxystrobinsensitive. The type II isolates were azoxystrobin sensitive or resistant. The G143A point mutationpredicted to cause a change from glycine to alanine at codon143of cyt b gene was found in allresistant isolates.Shift of sensitivity to boscalid (a succinate dehydrogenase inhibitor,SDHIs) from2012to2013in B. cinerea collected from strawberry, tomato, eggplant, and grape greenhouses inZhejiang province was monitored by the method of mycelial growth rate. The results showed thatthe sensitivity to boscalid in2013was significantly lower than in2012. In2012, the frequency ofsensitivity to boscalid was77.7%, low level resistance was13.3%, high level resistance was10%;In2013, the frequency of sensitivity to boscalid was64.9%, low level resistance was19.3%, highlevel resistance was15.8%. During mycelial growth and during spore germination. And, there wasno significant difference in mycelial growth, sporulation, sclerotial production, and pathogenicitybetween boscalid resistant and sensitive isolates. Further molecule research indicated that the244codon of SdhB gene of the boscalid sensitive isolates was serine（Ser，S）, the277codon was Histidine(His，H), but the244codon of SdhB gene of the boscalid resistance isolates wasthreonine（Thr，T）, the277codon was p-hydroxyphenylanine（Tyr，T） or arginine(Arg，R), we infer that The S244T and H277T,H277R point mutation was the molecule mechanism.Select36isolates of Botrytis cinerea collected from strawberry and grape in Lin’an、Zhu’ji、Jian’de、He’bei、Gan’su and An’hui. Sequencing the ITS gene、SdhB gene、cyt b gene、Tubgene,and set up a evolutionary tree. The results showed that the evolution of Botrytis cinereaisolates was no significant interrelated with region、host and whether resistance or not, except theSdhB gene.