Morphological and Molecular Characterization of Alternaria alternata Causing Leaf Spot in Faba Bean (Vicia faba L.) and Determination of The Disease Reactions of Some Faba Bean Varieties Grown in Turkey

Faba bean leaf spot disease caused by Alternaria alternata is an important fungal disease seen in the Antalya province of Turkey. The leaves and pods of faba bean (Vicia faba L.) showing signs of leaf spot were collected from faba bean plants in different parts of Antalya location between 2021 and 2022 in Turkey. The characteristic leaf spots were isolated from diseased faba bean leaves and confirmed as Alternaria alternata by morphological and molecular methods. Molecularly, the isolates were subjected to conventional PCR using ITS1/ITS4 primers (ITS region) which produced approximately 560 bp and AaltFor/AaltRev (beta tubulin gene) which produced approximately 184 bp. Fungus isolates belonging to Alternaria alternata species isolated in this research and isolates obtained from GenBank were in the same group and the similarity rate was determined as 100%. Reaction of different faba bean varieties to the fungus isolates in the pathogenicity test varied. Among the seven varieties used in the pathogenicity tests, the most susceptible variety was Otantik. Histal faba bean variety was determined to be the most resistant variety against all tested isolates. Thus, it will be possible to increase faba bean production and improve its cultivation in the world and in Turkey, by collecting Alternaria isolates and identifying local varieties and wild genetic materials resistant to these local isolates.