VEGETATIVE COMPATIBILITY GROUPS iN POPULATIONS OF Cryphonectria parasitica, THE CAUSAL AGENT OF CHESTNUT BLIGHT IN GUILAN PROVINCE, IRAN*

Document Type : Research Article

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Abstract

Chestnut blight disease caused by Cryphonectria parasitica, is one of the most important diseases affecting chestnut trees (Castanea sativa) in Guilan province. Seven sites from Shaft (Visrud, Taleghan and Babarekab), Lahijan (Shahbalutmahaleh and Gharibabad), Rezvanshahr (Doran) and Rasht were selected for investigating occurrence and frequency of vegetative compatibility groups. VCG were assessed according to the mycelial-barrage response on PDA. Among 272 evaluated isolates, four Iranian VCGs namely IR-1 to IR-4 were detected. Diversity of vc groups at individual localities was varied between one and two groups. IR-1 was the dominant VCG occurred at five populations, comprised 63.2% of all isolates and IR-4, with the lowest frequency (3%), occurred only in a single locality. IR-1 was the dominant group in Taleghan and Babarekab with 50/7% and 31/3% respectively. IR-3 was included 88% and 12% of all isolates in Shahbalutmahaleh and Doran respectively. The Shanon diversity index varied from zero to 0.58, with a mean of 0.20 for all regions.

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