اولین گزارش قارچ Neoscytalidium novaehollandiae از شمشاد خزری (.Buxus hyrcana Pojark)

Neoscytalidium species, a member of the family Botryosphaeriaceae, are known as plant pathogenic fungi, endophytes, saprobes, latent pathogens and also as causes of mycoses in humans and animals. The spectrum of symptoms caused by species in this genus is very wide and includes black canker, wilt, brown spot, blight, collar and root rot, necrosis and stem blight. In Iran, this fungal genus has been recorded from tree species such as pine, cypress, planes, poplar, pistachio and citrus, as well as from Magnolia and Calligonum species. Buxus is one of the important evergreen trees in industry and green areas. Some Buxus species, such as the Caspian buxus (B. hyrcana Pojark), are endangered, so identifying their pests and diseases is very important. In this context, Buxus leaves with symptoms of leaf spot were collected in the National Botanical Garden and cultured in PDA (Potato Dextrose Agar) culture medium in the pathology laboratory after surface disinfection. The macroscopic and microscopic morphological properties of the fungal isolates obtained were then examined on MEA (Malt Extract Agar) and PDA. Based on microscopic studies, N. novaehollandiae was identified as the cause of leaf spot in Buxus. The characteristic features of this fungus on the culture medium include the observation of arthritic conidia (a chain of conidia) and light brown conidia of various shapes, including without transverse wall, with one transverse wall, with two transverse walls and with multiple walls (muriform). The colony color on PDA and MEA media was black with a light border. To confirm the morphological identification of the fungal isolate through the molecular method, the ITS1-5.8S-ITS2 region was sequenced and its phylogenetic analysis was performed using the Bayesian method with other sequences in the database. This is the first report of boxwood infection with Neoscytalidium novaehollandiae. Given the importance of non-productive ornamental trees in green areas from various environmental aspects, it is very important to identify their pathogens.