The Detection On The Main Fungicides Resistance Of Botrytis Cinerea From Grape In China

Botrytis causes grey mold on Vitis vinifera,which can cause huge losses during the production of grape and storage period.Chemical applications are still the main method to control Botrytis cinerea in China.But B.cinerea had already have resistance to these fungicides.In this study,1494 isolates of B.cinerea,which were collected from six importance grapevine areas in China: Penglai,Jingzhou,Harbin,Taigu,Binchuan and Beizhen,and the EC50 of B.cinerea to carbendazim,procymidone,iprodione,fludioxonil,pyrimethanil,boscalid,imazail and thiram was measured,and the mode of action of imazail to controls B.cinerea,and whether exsited cross-resistance between imazail,thiram with other 6 fungicides were explored.Also we established the high-throughput method to detect mutation sites of the resistance.The results were as follows:1.Determination of EC50 values of B.cinerea to the main fungicidesThe EC50 of B.cinerea to the 8 fungicides were measured by the method of mycelial growth inhibition and conidial germination.The results showed that carbendazim had the highest of EC50 and it illustrated B.cinerea had the higest resistance level to these fungicides,And the the mean value of EC50 of fludioxonil was the lowest which meant that fludioxonil was the most effective one among all the fungicides.2.Detection of the resistance of B.cinerea to the main fundicides in China from 2016 to 2017In this study,we detected the resistance frequency of 1494 B.cinerea isolates to carbendazim,procymidone,iprodione,fludioxonil and pyrimethanil.The result showed that except fludioxonil other fungicides had lost their efficiencies in these areas,however,fludioxonil still showed low resistance frequency and may had good control effect.There were no sensitive or single-drug-resistance isolates in the areas of Penglai,Jingzhou,Taigu.There were different singledrug resistance and their frequences were all below 14% in Harbin and Bingchuan.3.Mode of action of imazail to B.cinerea and the cross-resistance between imazail,thriam with 6 fungicidesWe measured EC50 of imazalil to same isolates,by two methods--mycelial growth inhibition and conidial germination,in order to explore the mode action of imazail to B.cinerea.The results showed that the mode of actions of imazail to B.cinerea is mycelial growth inhibition,And there were no cross-resistance bentween imazail and thiram with the 6 fungicides.4.Method by high-throughput sequencing was established to detect the resistance of B.cinere to the main fungicidesThe method of high-throughput sequencing was established to detect the mutation sites and the resistant frequencies of B.cinerea to the main fungicides.In this study,we detected 384 isolates of B.cinerea,and found out that there were 22 new mutation sites in the mrr1 of 184 isolates.We inferred that these new mutation sites might be result for the MDR1 genotype.And,high-throughput sequencing would be an efficient,sensitive,convenient and cheaper method to detect the resistance of B.cinerea to fungicides,which could be used widely.