First Detection of Wilsonomyces carpophilus Causing Leaf Spot and Shot Hole Disease on Vitis vinifera

Abstract

Grapevines ( Vitis spp.) are cultivated all over the world and viticulture is a horticultural industry. During the spring of 2020, leaf samples with leaf spot and shot-hole symptoms were collected from the vineyards of Urmia county, West Azerbaijan province, Iran. One fungal isolate was recovered from infected tissues. Based on cultural and morphological features, ITS rDNA sequence data, and a generated phylogenetic tree, the obtained fungal isolate was identified as Wilsonomyces carpophilus. Under in vitro conditions, the colony was white to cream colored, sporulation occurred only in a minor proportion of the colony, and the diameter of the colony on potato dextrose agar reached 44 mm after 14 days. To evaluate Koch's postulates, isolate NSS18 was inoculated on leaves of the Chafteh cultivar of grapevine and the same fungus was reisolated from developed symptoms. This is the first report of leaf spot and shot-hole disease on grapevine caused by W. carpophilus, and also Vitis vinifera is a new host for this species in the world.