Phytophthora austrocedrae Gresl. & E. M. Hansen / JKI, Julius Kühn-Institut, Federal Research Centre for Cultivated Plants ; Sabine Werres/Matthew Elliot/Alina Greslebin

Abstract

Phytophthora austrocedrae Gresl. & E.M. Hansen is a Phytophthora species that up to now has only attacked needle trees and shrubs. It was first detected in Argentina on Austrocedrus chilensis (Chilean incense cedar, Cupressaceae). This conifer is naturally distributed in Argentina and in Chile. It is the most important conifer species of the Andean Patagonian forest. Disease symptoms had been observed since 1948 (Varsavsky et al., 1975 cited from Havrylenko et al.,1989; summary of the history of Austrocedrus chilensis decline in Filip & Rosso 1999, and La Manna & Matteucci 2012) but the causal agent could not be identified before 2007. In Europe P. austrocedrae had first been reported in UK in spring 2011 in a public park where it could be isolated from diseased Chamaecyparis nootkatensis (Nootka cypress, Cupressaceae) and from C. lawsoniana. (Lawson’s cypress, Cupressaceae). The first cases of P. austrocedrae in the natural environment in the UK were discovered on Juniperus communis (common juniper, Cupressaceae) in the North Pennines, England in 2011. A recently made sequence analysis of an unknown Phytophthora isolate stored in the JKI culture collection showed that this isolate is a P. austrocedrae (Wagner and Werres, unpublishded data). It was isolated in 2001 from Juniperus horizontalis ‘Glauca’ (R. Ulrich, personal communication) and originated from a German nursery that imported plants. So it seems that P. austrocedrae has been present in Europe earlier than 2011.