اولین گزارش از چهار گونه Fusarium همراه با زوال درختان تبریزی در ایران

Poplar trees (Populus nigra) belong to the genus Populus and the family Salicaceae. These trees are the most important ornamental trees in green space which in addition to the beautiful view that they create in the urban green space due to their high tall and beautiful crown, also have economic and commercial applications. Cold resistance and rapid growth are important features of these trees. In the past few years, Populus trees have dieback in the Ardabil and Namin cities. Because the incidence of dieback can cause these important trees to decay in the green space, during the summer and autumn 2018, samples were collected from the roots of trees with signs of decline in Ardabil and Namin. The infected roots were gently washed under running water and surface sterilized (dipping in 0.5% sodium hypochlorite for 5 min) and rinsed three times in distilled water, dried in a sterile filter paper. Samples were plated on PDA culture medium. In this research, some species of Fusarium were isolated, which were identified using valid keys and morphological characteristics on PDA and SNA such as color, growth rate and type of colony and microscopic features such as shape and size of macroconidia and microconidia, presence or absence of microconidia, size of phialides, the presence or absence of false heads and chlamydospores and the shape of chlamydospores. According to these characteristics, Neocosmospora solani (Fusarium solani) from poplar trees of both Ardabil and Namin, F. oxysporum from Ardabil and F. acutatum, and F. avenaceum from roots of Populus trees in Namin were identified. To our knowledge, all four species are reported for the first time on P.nigra trees in Iran and N. solani, F. avenaceum and F. oxysporum for the first time on P. nigra trees in the world.