Endophytic Yeasts for the Biocontrol of Phlyctema vagabunda in Apples

Abstract

Bull’s-eye rot, produced by Phlyctema vagabunda, is an important postharvest disease in apples. Current measures to control infection include synthetic fungicides, in addition to the application of copper hydroxide and potassium phosphite. However, growing public concern regarding fungicide residues in food has generated interest in developing non-chemical alternative control methods; biological control is one of the most promising alternatives. In this research, native endophytic yeasts were isolated and evaluated for the biocontrol of P. vagabunda in apples. The mechanisms of action involved were also determined. Our research found 2 isolates, Vishniacozyma victoriae EPL4.5 and EPL29.5, which exhibited biocontrol activity against P. vagabunda at 20◦C in apples, the incidence of bull’s-eye rot was reduced by 39% and 61%, respectively, and the severity of the disease was decreased by 67% and 70%, respectively, when apples were inoculated with these yeasts 24 h before applying the pathogen. The main mechanisms that could be involved in the observed biocontrol activity are the ability to form biofilms and the production of volatile organic compounds.