Chestnut blight in Portugal -: Monitoring and vc types of Cryphonectria parasitica

The reduction of the Portuguese chestnut area has been attributed to socioeconomic changes and also to the occurrence of pathogenic fungi as Phytophthora spp. (mainly R cinnamomi) and, in the last two decades, Cryphonectria parasitica. In order to improve the knowledge about the C parasitica population, a countrywide survey was conducted in 185 sites from 8 Agriculture Departments (mainland and islands). The results showed that chestnut blight has spread into most of the chestnut growing areas in Portugal including the Azores and Madeira Islands. Among 606 C parasitica isolates sampled throughout Portugal, 9 vegetative compatibility (vc) types were detected. The vc type designated P-2 is the most widespread comprising 78%, of the isolates.