First molecular identification of Fusarium oxysporum causing Fusarium wilt of Armenian cucumber in Iraq

Abstract

Cucumis melo var. flexuosus, which is commonly known as Armenian cucumber is one of the most economically important species of the family Cucurbitaceae. In June of 2018, wilt symptoms were observed on Armenian cucumber plants in Fadhilia, Ninevah governorate, North of Iraq. The fungus was isolated from diseased tissues and initially identified based on, its morphological characterizations using conidial and hyphal structures. Pathogenicity of the fungus was also confirmed by Koch’s postulates. Molecular identification of the fungal pathogen was done by amplifying the internal transcribed spacer (ITS) region of the conserved ribosomal DNA. All these ITS sequences showed homologous to those of Fusarium oxysporum isolates in the GenBank database with a similarity percentage of 99%. To the best of our knowledge this is the first molecular record of F. oxysporium on the Armenian cucumber in Iraq.