Host range and certain morphological characteristics of three similar high temperature species of Phytophthora parsiana, P. hydropathica and P. irrigata

High temperature oomycete Phytophthora parsiana is one of the causal agent of pistachio gummosis in Iran which originally was isolated from fig in Iran. Phytophthora hydropathica and P. irrigata two newly described high temperature species similar to P. parsiana were recently isolated from irrigation streams and some ornamental plants from USA .In the present study all three species produced chlamydospores in infected crown and root tissues of apricot.. No morphological differences were observed among species. Among woody plants inoculated Pistacia vera cv Sarakhs, almond and apricot were highly susceptible to all species. Pistacia mutica, P. khinjuk, walnut, fig and mango were susceptible to P. parsiana and P. hydropatica but P.vera cv Qazvini was infected only by P. hydropathical. Loquat ( Eriobotryae japonica) and Christ,thorn jupube (Zizyphus spina-christi) were not infected by all species. All annual herbaceous plant species used none were infectd with all species.