Effects of biocontrol activity of ascomycetes yeasts isolated from natural resources on gray mold fungus (Botrytis cinerea) using dual culture method

The gray mold disease caused by Botrytis cinerea is one of the important post-harvest diseases especially in apple and Strawberry. In order to biological control of B. cinerea, we used 14 isolates of ascomycetous yeasts obtained from natural resources and plants. For molecular identification of yeast isolates, genomic DNA extracted and D1/D2 domain of the large subunit (LSU) rDNA gene sequenced. Nine species including Pichia kudriavzevii, Pichia galeiformis, Galactomyces candidum, Meyerozma guilliermondii, Saccharomyces cerevisiae, Zygoascus meyerae, Pichia sp., Candida parapsilosis, Metschnikowia sp., Candida boidinii, Lecythophora sp. and Candida catenulatea were identified based on sequence similarity of D1/D2 domain of the LSU rDNA gene of the isolates with those in NCBI database. The dual culture method used for assay of their biocontrol activity against of B.cinerea on potato dextrose agar medium in a completely randomize design with tree replications. Our results show that highest inhibitor effect related to G. candidum with 47.85 percent and lowest effect related to P. kudriavzevii with 6.53 percent. In this study, yeast isolates obtained from natural resource and plants showed high biocontrol activity against of B. cinerea.