Genetic and Phenotypic Diversity among Botrytis cinerea Isolates in Iran

Abstract Forty‐four Botrytis cinerea isolates from different hosts and geographical regions were studied for colony morphology, mycelial growth rate at different temperatures, pathogenicity and molecular diversity. Botrytis cinerea isolates had temperature optima of 20–25°C and isolates showed variation in growth rate at different temperatures. Two morphological types were identified among tested isolates: mycelial and sclerotial. The pathogenicity of isolates was tested on grapevine leaves, and it was revealed that nine of 44 isolates were non‐pathogenic and among them seven were of mycelial type. There was no correlation between mycelium growth rate and pathogenicity. Genetic diversity was investigated using nine arbitrary decaprimers. No relationship was found between molecular clusters and geographical region or sampling time; whereas isolates from the same plant host tended to cluster with each other. Seven of nine non‐pathogenic isolates were separated from pathogenic ones.