پوسيدگي فيتوفتورايي ريشه و طوقه تعدادي از گياهان زراعي و باغي منطقه گرگان *‌

PHYTOPHTHORA ROOT AND CROWN ROT OF SEVERAL FIELD AND ORCHARD CROPS IN GORGAN AREA

در سال‌هاي 89-1388 از مزارع كشت آبي، نهالستان‌ها و باغ‌هاي مختلف منطقه گرگان در استان گلستان بازديد و از گياهان بيمار با علايم مرگ گياهچه، پوسيدگي ريشه و طوقه، بوته ميري و پوسيدگي ميوه نمونه‌برداري شد. نمونه‌ها پس از شستشو و ضدعفوني سطحي، در محيط كشت نيمه انتخابي جداسازي فيتوفتورا CMA+PARPH)) كشت شد. تشخيص گونه‌ها با ويژگي‌هاي ريخت‌شناسي و فيزيولوژيك، و براساس كليدهاي شناسايي معتبر براي تشخيص اين جنس و هم‌چنين توالي نوكليوتيدي ناحيه ITS دي-ان- ا ريبوزومي انجام گرفت. تعداد 50 جدايه از جنس فيتوفتورا شامل گونه‌هايPhytophthora palmivora ،P. cryptogea گروه II ،P. citrophthora ‌، nicotianae .P وP. inundata جداسازي و بيماري‌زايي گونه‌ها روي ميزبان‌هاي مربوطه به اثبات رسيد. گزارش بيماري‌هاي: پوسيدگي فيتوفتورايي ريشه و طوقه زيتون با عامل، P. palmivora ،پوسيدگي ريشه نهال‌هاي كيوي، سيب‌زميني و ژربرا با عاملP. cryptogea گروه II و پوسيدگي ريشه و طوقه باقلا با عاملP. inundata براي ايران جديد است.

During 2009 and 2010 growing seasons, different irrigated fields were surveyed in Gorgan region. Infected plants with symptoms such as damping off, crown and root rot, and foliar blight were collected. Samples were washed in running tap water and cultured on CMA+PARPH. Isolates were identified on the basis of morphological and some physiological characteristics.50 isolates belonging to four species were identified. The species were: Phytophthora citrophthora from persimmon fruits (Diospyros kaki); Phytophthora cryptogea from kiwi trees (Actinidia chinensis) with root and crown rot sympotoms, crown and root of potato (Solanum tuberosum) and gerbera (Gerbera jamesonii), Phytophthora nicotoanae from tomato (Lycopersicum esculentum) root and stem, Phytophthora palmivora from root and crown of olive (Olea europae) seedlings and Phytophthora inundata from root and stem of broad bean (Vicia faba). All of Phytophthora isolates were found pathogen on their host at greenhouse conditions. Based on our knowledge isolation of P. cryptogea group II from kiwi and potato and Phytophthora palmivora from olive trees were new for Iran, also P. inundata from broad bean was new for Iran and the world.