Resistance,Rapid Detection And Control Of Botrytis Cinerea From Strawberry To Procymidone In Zhejiang Province

Strawberry grey mould,caused by Botrytis cinerea,is one of the most harmful diseases in the strawberry production.At present,chemical control is the main method to control strawberry grey mould,and the procymidone of diformimide fungicide is widely used.Meanwhile,B.cinerea is one of the pathogens with the highest resistance risk listed by the fungicide resistance action committee(FRAC).Therefore,it is of great significance for the control and fungicide resistance management of grey mould to make clear the current situation of resistance to commonly used fungicides in production and to carry out resistance risk assessment before the new drugs are put into use.In this study,the resistance to procymidone was determined.Based on the molecular mechanism of resistance to procymidone,a rapid detection technology of B.cinerea resistance to procymidone in the early stage of infection was established.The resistance risk of the new fungicide was evaluated to provide the basis for the subsequent application of the new fungicide(Y13149).The main results are as follows:(1)The total resistance frequency of 200 strawberry grey mould isolates from 5 regions in Zhejiang Province to procymidone is 71.5%;the procymidone resistant strains are dominated by low-level resistance,accounting for 69.9% of all resistance strains.There were three mutation types in Bc OS1 gene of resistant strains,which were I365 S,I365N and Q369 P + N373 S,respectively.Among them,the first two types of mutations will cause Botrytis cinerea to exhibit low or medium level resistance to procymidone,and Q369 P + N373 S type strains show high-level resistance.The resistant strains were less suitable than sensitive strains and more sensitive to osmotic pressure and oxidative stress.There is a clear suitability compensation effect.(2)A rapid detection system of procymidone resistance of strawberry plants in the early stage of infection by B.cinerea was established.There are two step loop-mediated isothermal amplification(LAMP).The first step is to detect whether the asymptomatic strawberry plants are infected by B.cinerea,the second step is to check whether the infected B.cinerea has a high resistance level to procymidone,Which is the Q369 P genotype.It can determine whether procymidone can continue to be used.In theory,the system can detect genomic DNA as low as 10×10-3 ng / ?L,which can be used for on-site rapid detection of resistance of B.cinerea to procymidone in the field.(3)The sensitivity baseline of B.cinerea to the novel succinate dehydrogenase inhibitor(SDHI)fungicide flubeneteram was established in Zhejiang Province,with an average EC50 of 4.36±0.95 ?g /ml.Flubeneteram has no cross resistance to procymidone.Besides it has no cross-resistance with the existing main agents for the prevention and treatment of grey mould,including boscalid which is also SDHI fungicide.Three resistant mutants were obtained by drug acclimation,with the mutation frequency of 4‰.The resistant mutants decreased in growth rate,sporulation and pathogenicity.The moderate mutant resistance cannot be stably inherited.Therefore,it is considered that the resistance risk level of B.cinerea to flubeneteram was low or medium.It is suggested that flubeneteram can be used to control strawberry grey mould,especially by means of rotation for resistance management of procymidone.