شناسايي گونه هايPhytophthora عامل پوسيدگي طوقه و ريشه درختان گيلاس در استان تهران

IDENTIFICATION OF Phytophthora SPECIES THE CAUSING ROOT AND CROWN ROT OF CHERRY TREES IN TEHRANPROVINCE

Phytophthora species cause root and crown rot of wide host range of herbal and woody plants making heavy loss. The loss in woody trees are more important than other agricultural crops. In this study Phytophthora species,causing root and crown rot of stone fruit trees throughout Tehran province were identified and the distribution of the diseases was determined. Based on the decline and wilting symptoms of cherry trees,the discolored tissues of the collar region of infected trees were removed, and after surface disinfection the tissues were plated on semi selection medium (PARPH), and Phytophthora species were isolated. Features and cardinal temperatures ,the following species were identified. P. cactorum (from Karadj, Lavasan and Soulaghan), P. citrophthora (from Kan and Soulaghan), P. drechsleri (from Shemiran and Karadj), P.cryptogea (from Karadj). The most frequency and the least one were related to P. cactorum and P. cryptogea respectively. The pathogencity of isolates were proved on detached stem and collar region of Mahaleb cherry seedlings.This is the first report of P. cactorum, P. drechsleri and P. cryptogea on cherry trees.