IDENTIFICATION OF APPLE FRUIT BACTERIA AND EVALUATION OF THEIR BIOCONTROL POTENTIAL AGAINST APPLE BLUE MOLD (PENICILLIUM EXPANSUM (IN WEST AZERBAIJAN PROVINCE

Background and Aim:Apple blue mold ( Penicillium expansum Link) is the most important postharvest disease worldwide. it has numerous mycotoxins. Fungicide resistance development and concern for public safety from fungicide residues on fruits has led to the search for alternative control measures including biocontrol for the management of storage diseases of pome fruit. the study aimed to identification and evaluate biological control potential of bacteria associated with apple fruits against apple blue mold.Methods:apple Red and Golden cultivars were taken from Mahabad, Urumieh, Shahin Dezh and Miandoab cities cold storages during 2016 – 2017. Due to bacterial isolation and identification, apple healthy samples were selected. Suspension serially diluted and cultured on NA. To screening and assessment bacterial strains potential antagonistic ability, dual culture test between bacteria and fungus was conducted on plates with PDA+NA media. After few days inhibitory zone diameters were measured.Results:Among 60 isolates, 16 had inhibitory zone. Among them 10 bacteria with bigger inhibitory zones were selected for biochemical and physiological tests and their phenotypic characterization were determined. among selected isolates 4 of them are Gram negative and 6 are gram positive, all are oxidase and catalase positive and their hypersensitivity reaction test are negative on geranium leaves. on the basis of biochemical, physiological and nutritional tests the isolates identified as Pseudomonas fluorescens, Bacillus subtilis And Bacillus licheniformis.Conclusion:Biological control by bacteria and yeasts was reported formerly, In this study good results obtained in vitro condition. gram positives were more effective and common than gram negatives.

Keywords:

biological control , postharvest disease , public safety