The Endophytic Fungus Albifimbria verrucaria from Wild Grape as an Antagonist of Botrytis cinerea and Other Grape Pathogens.

Gray mold, caused by Botrytis cinerea, is one of the most prevalent fungal diseases in table and wine grapes, affecting grape quality and yields. In this study, we isolated several endophytic fungi, including Alternaria alternata, Bipolaris cynodontis, Phoma sp., and Albifimbria verrucaria, from leaves of Amur grape (Vitis amurensis) cultivar Shuangyou and investigated their biocontrol activity against B. cinerea. In vitro dual assay showed that A. verrucaria isolate SYE-1 inhibited growth of B. cinerea. The isolate also had a wide range of biocontrol activity against Lasiodiplodia theobromae and Elsinoë ampelina. Mycelial growth and conidium germination of B. cinerea were significantly inhibited by metabolites of A. verrucaria in agar plates and culture extracts of A. verrucaria from liquid culture. The isolate produced a total chitinase activity of 0.4 U/ml after incubation for 10 days in Czapek's liquid medium. In addition, application of culture extracts of A. verrucaria prior to B. cinerea inoculation significantly reduced disease severity on grape leaves of the susceptible cultivar Red Globe. Taken together, our results indicate that A. verrucaria has potential as a biocontrol agent to control grape gray mold.