Methods for screening new Ampelomyces strains to be usedas biocontrol agents against grapevine powdery mildew

Abstract: Grapevine powdery mildew is a key disease all across Europe and is currently controlledalmost exclusively using fungicides. To develop a new biofungicide product against this disease,caused by Erysiphe necator, a large culture collection of Ampelomyces strains collected worldwidefrom different powdery mildew species was screened to assess for the first time the level ofvariability of different characteristics of these biocontrol agents known to occur as naturalmycoparasites of powdery mildews in the field. This preliminary screening revealed a considerablediversity in many characteristics of different Ampelomyces strains including both culture patternsand mycoparasitic activities against the asexual and sexual stages of E. necator. The screeningprotocol developed in this work could be used in further studies on Ampelomyces in order todevelop new effective commercial biofungicide products against powdery mildew infections ofgrapevine and other crops.