Survey and geographic distribution of chestnut blight in Portugal

Abstract

Cryphonectria parasitica, the fungus that causes chestnut blight disease, was first described in Portugal (1929) on bark samples of Castanea crenata, collected in Beira Interior province. After this report, only in 1989 two disease foci were found on native European chestnut, C. sativa, in Trás-os-Montes e Alto Douro Province. To assess the current distribution of chestnut blight in Portugal (mainland, Azores and Madeira) a nationwide monitoring program was implemented. A major cooperative effort, involving all the Portuguese Forest and Agricultural Services, was created for this endeavor and coordinated by the National Forestry Station. A total of 191 chestnut stands was surveyed across the entire country. C. parasitica was isolated from 56.5% of the sampling sites (108 sites). Sampled parcels were digitally geo-referenced and mapped. In addition, a collection of C. parasitica isolates has been established and the study of the molecular variability of C. parasitica in Portugal is underway.