مکانیسم‌های بیوکنترلی مخمرهای سرمادوست جداسازی شده از اپیفیت انگور در کنترل بیماری کپک خاکستری

Gray mold caused by Botrytis cinerea is the most common and serious postharvest diseases of grape responsible for significant economic losses worldwide. A wide range of yeasts have been reported to exhibit inhibitory activity against B. Cinerea. In recent years, studies have been undertaken not only to develop new antagonists from the natural environment, but also to understand their possible mechanisms of action in the host-pathogen-antagonistic interaction system, which is necessary for their future commercial application. This work aimed to investigate mechanisms of yeast isolates with antagonistic activity. In this study mechanisms involved Production of lytic enzyme, volatile organic compounds (VOCs), production, biofilm formation and production of sidrophore were evaluated. The different modes of action of three isolated epiphytic yeast species Metschnikowia pulcherrima (G9), Rhodotorula glutinis (G54) and Meyerozyma guilliermondii (G30)) against B. cinerea was investigated. All of tested isolates showed high ability to production of lytic enzymes (Protease, Amylase and Pectinase) that is important mechanism involved in the biocontrol activity and responsible for fungal cell wall degradation. Also formation of biofilm all observed in all strains. Biofilm formation, adhesion to fungal mycelium was considered one of the key mechanisms of biological control of the tested isolates. The iron depletion (Sidrophore production) observed in M. pulcherrima (G9) and R. glutinis (G54). All of the three isolates were able to production different levels of volatile organic compounds (VOCs) and R. glutinis (G54) was more effective than other two isolate at limitation of mycelium grows of B. cinerea. Finally, it was found that various mechanisms play role on the biocontrol ability of studied yeasts isolates. This species may involve other modes of action to inhibit Botrytis cinerea, such as formation of another hydrolysis enzyme, induce resistance and competition for space and nutrients. This might need further investigation.