Fungal pathogens associated with crown and collar rot of apple trees insouthern Syria

摘要

Crown and collar rot of apple trees is a destructive and widespread disease in most areas of the world. Surveys have been done to describe disease symptoms, estimate the disease incidence, and identify the pathogens associated with this disease in southern Syria. Disease incidence was 0.08 - 10 % in most studied sites, only in Alroom location it was up to 14.7 % in 2014 and 17.8 % in 2015, with average of 11.8 %. Symptoms included small pale green leaves, sparse foliage, and a reddish-brown discoloration of inner bark of the infected area at the base of infected tree. The isolated fungi belonged to genera and form genera Phytophthora, Rosellinia, Rhizoctonia, Phialophora, Acremonium, Pestalotiopsis, Cylindrocarpon and Verticillium. Phytophthora wasisolated from all infected trees, and was the most frequent pathogen (53.7 % of total isolates). Phytophthora isolates recovered from crown cankers of apple were identified as P. cactorum (91.5 %) and P. cambivora (8.5 %). The results of this study are the first report of crown and collar root rot of apple in Syria.