Molecular Identification and First Report of Fusarium annulatum Inciting Wheat Root Rot on Bread Wheat in Iraq by Multi-Locus Phylogenetic Analysis

Fusarium spp. are very important plant, animal, and human pathogens. In this study, field severe wilt infection in bread wheat was observed in January 2021 in the wheat field of the Muradia Agriculture Station, Babylon, Iraq. Disease symptoms on the roots were observed as brown discoloration and root rot. Pathogen isolation, morphological characterization, pathogenicity, and sequencing of ITS, TEF1-α, TUB2, and ACT regions, and the phylogenetic analysis with multi-gene of the isolated pathogen were performed. The results obtained revealed that the multigene phylogenetic trees using Maximum Likelihood phylogenetic analysis in addition to morphological characteristics confirmed the identification of Fusarium annulatum. Phylogenetic analysis utilizing Bayesian and Maximum Likelihood trees based on only ITS sequences and ITS data was not sufficient to distinguish this species among Fusarium spp. However, the results of phylogenetic analysis using Bayesian and Maximum Likelihood trees based on TEF1-α region or multigene phylogenetic analysis showed that isolates of F. annulatum were grouped in a distinct species clade belonging to the Fusarium spp. This work is considered as the first molecular identification using 3-gene phylogenetic analysis and first report of F. annulatum as a wheat pathogen in Babylon, Iraq.

Keywords:

Fungal disease, Triticum aestivum, multigene phylogenetic analysis, Fusarium, soil borne disease.