Selecting highly effective strains of Ampelomyces quisqualis for the controlof powdery mildews

Abstract: Genetically different Ampelomyces quisqualis strains isolated from different locations,fungal hosts and host plants were selected; pathogenicity and aggressiveness on differentpowdery mildew species were evaluated. Under controlled conditions all the selected strainsreduced the sporulation of powdery mildews (Podosphaera xanthii, Podosphaera aphanis), butwith a different level of reduction among strains. Strains can be divided in highly and poorlyaggressive, and their behavior is similar on the studied powdery mildews. The susceptibilityversus A. quisqualis varies among the different tested powdery mildews. Results suggest thatthere are not adaptations of A. quisqualis to powdery mildew species from whatever was theoriginal host specie the mycoparasite strain was isolated as no differential interaction wasobserved, independently of their phylogenetic groups or geographical origin. Some of the testedstrains could be appropriate candidates for future commercial development in environmentalconditions to control different powdery mildew species.