Faba bean (Vicia faba L.) is one of the foremost vegetable crops in Iraq and worldwide. Faba bean has also become a traditional food in different parts of the world, with cultivations mainly for their protein-rich pods. Faba beans sustain several fungal pathogen infections, which lead to considerable yield losses. Among these, the leaf spot disease is more prominent and considerably impacts the quality and quantity of faba bean production. In Iraq, the leaf spot disease has emerged as a significant problem in bean fields caused by several pathogens. In the presented work, sizable efforts focused on isolating and identifying fungal pathogens of the leaf spot disease in faba beans at the Basrah Governorate, Iraq. The study might also be the first report on the fungal species Exserohilum rostratum as a true pathogen of faba bean leaf spot disease in Iraq. The morphological and molecular diagnoses identified the pathogen by applying the internal transcribed spacer (ITS) gene. Searching the sequenced PCR products used the NCBI-BLAST website. The results proved a 99% similarity to the known fungus E. rostratum, with an eventual submission to NCBI under the gene accession number LC769969. The pathogenicity experiment materialized following Koch’s hypotheses to confirm the causative agent. The presented findings revealed the potential pathogenicity of this microbe on the aerial parts of the faba bean (V. faba L.) for the first time in Iraq.
Faba bean (V. faba L.), Exserohilum rostratum, leaf spot disease, morphological and molecular identification, pathogenicity
The appropriate study identified the fungal species Exserohilum rostratum as a potential threat in cultivating faba bean (V. faba L.) in Iraq. This research represents the first report of its pathogenic effect on aerial parts (stems, leaves, and pods) of the faba bean plants in Iraq.