Vegetative compatibility type diversity of Cryphonectria para- sitica populations in Bosnia-Herzegovina, Spain and France

Cryphonectria parasitica, the causal agent of the chestnut blight, has been responsible for con siderable damage in chestnut ecosystems in several European countries in the last three decades. Vegetative compatibility types (vc types) were characterized in three countries as a tool to assess C. parasitica diversity in Europe and because hypovirulence, caused by a hypovirus, spreads through anastomosis between compatible isolates. In Bosnia-Herzegovina, eastern Spain (Catalonia) and France several areas were investigated. Canker samples were removed from several sites, and vc types determined using the European vc type testers. Vc type diversity was assessed with the Shannon index. C. parasitica populations appeared clearly differentiated inside each country and among the countries. In Bosnia-Herzegovina, dominant vc types were EU-1, EU-2, EU-12 or EU-13, de pending upon the region. All the other vc types found there belonged to the first 31 EU vc types. In Spain the dominant vc type was EU-2, six isolates were distributed in vc types between EU-65 and EU-74, and one vc type was incompatible with all the European vc type testers. In eastern France, dominant vc types were EU-1 and EU-5, whereas in western France, dominant vc types were EU-33 or EU-72, and 15 vc types were incompatible with all the European vc type testers.