مشخصات پژوهش

Esca and petri diseases are two of the most important grapevine diseases worldwide. Several hyphomycetes including Phaeoacremonium spp. and Phaeomoniella chlamydospora , as well as some basidiomycetes fungi such as Fomitiporia mediterranea are known as the main fungal agents associated with these diseases. Vine trees with die-back and dwarfing signs and typical symptoms on the leaves show light green or choloroisis, irregular spots between the veins or along the leaf margins that usually spread outward to distal parts of the shoots, - deterioration become visible together with or even preceding white rot including small, dark brown or black spots in cross section appear as deep brown or black streaks or columns in longitudinal section. On old trees, the most common symptoms inside trunk and main branches is white rot, which gradually changes the hard wood to a soft, friable, spongy mass. . Esac and petri cause slow decline and able to finally destruct young and old vines. Among these fungal agents, Phaeomoniella chlamydospora can infect young vines, while Phaeoacremonium spp. and basidiomycetous fungi are mainly causal agents of the disease in old vines. During an investigation on fungi associated with grapevine decline in Qazvin province, during 2014-15, 58 fungal isolates from different locations in Qazvin province such as Takestan, Tarvizak, Narjeh and khorramdasht were obtained from vines with decline symptoms and purified using single spore method. The isolates were identified based on microscopic features such as colony color, mycelium cell size and surface ornamentation, conidiophore characters including width, ramification and type of the phialids; and features of conidia such as shape and size by using relevant literatures. Furthermore, for molecular identification, whole-cell DNA was extracted from mycelia by CTAB method. ITS-rDNA region and partial of Beta tubulin gene were amplified by polymerase chain reaction using ITS1/ITS4 and Bt2a/Bt2b primers, resp