BIOCONTROL BACTERIA AGAINST BOTRYTIS GRAY MOLD AND OTHER STRAWBERRY FUNGAL PATHOGENS

Abstract

Strawberries are listed among the functional foods. Beside their appreciated taste, they are rich in antioxidant compounds. Due to their sugars, fleshy pulp and thin skin, as well as dwarf habitus, they are exposed to various plant diseases, especially fungi. Botrytis gray mold is the most destroying pathogen, but there are other fungi that can cause losses in the field or after harvest. The aim of this study is to select some bacterial strains that could be easily formulated as biocontrol agents against various molds. These bacteria were isolated from winery semi-composted marc and analyzed through specific microbiologic methods. Based on their in vitro antagonistic activity, two bacterial isolates were selected. These strains revealed up to 84.2% inhibition of Botrytis cinerea growth, and high antifungal activity against various other fungi, such as Fusarium oxysporum, Macrophomina phaseolina and Sclerotinia sclerotiorum. Qualitative enzymatic tests, as well as microscopic analysis of the microbial interactions revealed fungal degradative enzymes produced by the bacterial strains. As the selected strains were determined to be spore producing bacteria, long term preservation is an advantage for their formulation as plant protection inoculants. Moreover, these bacteria revealed no phytotoxic activity against test plants.