Identification of bean root rot casual and associated fungal agents in Khomein county, Markazi province, Iran

Beans are major feed crops belonging to the family Leguminosae, representing one of the most consumed legumes in Iran. Root rot diseases account for high yield losses in bean crops annually, driving the need to identify causative pathogenic agents. During the cropping season of 2019, samples were collected from rhizosphere and infected plant tissues in Khomein county. Of the total 80 purified isolates, 19 fungal isolates were selected for morphological and molecular identification studies. Fusarium equiseti, Fusarium acuminatum, and Macrophomina phaseolina were isolated from the infected crown and root tissues. Their pathogenicity on bean cultivars (Yaghout, Dorsa, and Koosha) is reported for the first time from Markazi province. However, the pathogenicity of fifteen saprophytic and pathogenic fungi species that are isolated from the rhizosphere needs to be confirmed in further studies. Disease symptoms were found to be more severe on pinto beans than red and white beans. In all cases, molecular studies using ITS and tef genomic region confirmed the morphological results. Briefly, these fungal species are introduced as bean root rot causal agents in Khoemin county, which needs to be considered in upcoming breeding programs.