بررسی مقدماتی علل عمده زوال درختان پده در برخی رویشگاه‌های حاشیه رودخانه ارس

Populus euphratica is a valuable plant species that has naturally spread across large areas of Iran. It is distributed in hot, arid, semi-arid, and desert regions with moderate, cold, and very cold winters in the north and northwest, center and northeast, east, south, and southeast along the creeks and rivers, including the Atrak, Aras, Jajroud, Karun rivers. A notable characteristic of this species is its tolerance to soil dryness and salinity. The presence of salicylic acid (SA) compounds in its bark provides a chemical defense, causing Populus euphratica to show an incompatible reaction to living pathogens; however, some pathogens still cause significant damage. This damage appears to be increasing due to climate changes and weather tensions. In recent years, symptoms of decline, decay, and drying of branches and trunks have been observed in some Populus euphratica habitats along the Aras River in East and West Azerbaijan provinces in Iran. The continued climate tensions have exacerbated the spread of this disease, leading to the complete desiccation of some trees. As a part of a pest and disease monitoring project in the Iran Turan region, preliminary morphological studies were conducted. These studies examined the shape and color of colony, the shape, color, and dimensions of pycnidia, conidiophores, conidia, and basidiospores, as well as the shape, color and characteristics of basidiocarps. The fungi Inonotus sp. and a species of Cytospora sp. were identified as significant contributing agents to the decline of Populus euphratica trees along the Aras River.