Genetic structure of Biscogniauxia mediterranea fungus populations in Zagros forests of Iran
摘要
Biscogniauxia mediterranea is an opportunistic fungal pathogen associated with charcoal canker disease in both juvenile and mature oak trees. This study investigated the genetic diversity, population structure, and pathogenic variability of B. mediterranea populations in the Zagros forests of Iran using inter-simple sequence repeat (ISSR) markers, with the goal of supporting effective forest disease management strategies. A total of 159 isolates were obtained from symptomatic oak trees in four ecologically distinct provinces: Fars, Ilam, Kermanshah, and Kohgiluyeh & Boyer-Ahmad. Genetic analyses revealed high genetic diversity and clear geographic structuring. Most genetic variation occurred within populations, while significant differentiation among regions was detected. Population structure analyses indicated the presence of major genetic groups associated with geographic origin, with additional overlapping patterns suggesting gene flow among regions. Pathogenicity tests confirmed that all tested haplotypes were capable of causing charcoal canker, with isolates from western regions exhibiting greater aggressiveness than those from the southwest. Overall, the findings indicate that geographic and environmental factors are associated with variation in both the population structure and pathogenic potential of B. mediterranea, providing guidance for targeted management of oak decline in the Zagros forests.