Identification and pathogenicity of Fusarium species causing bean root rot with emphasize on phylogenetic study and host range of Fusarium solani species complex in Markazi Province

Fusarium rot is one of the most important diseases of beans (Phaseolus vulgaris). In order to identify Fusaria that cause bean root rot in Markazi Province (Iran), in the summer of 2018 and 2019, several bean fields were visited and infected plants with root rot were sampled and the fungi were isolated in the laboratory. Based on morphological and sequencing characteristics of internal transcribed spacers of rDNA (ITS) and translation elongation factor 1-α (EF-1α) gene regions, 37 Fusarium isolates, including Fusarium oxysporum species complex, F. solani species complex, and F. lateritium species complex, as well as F. equiseti, F. acuminatum and F. redolens were identified. All isolates caused root rot on Sadry bean cultivar. Since F. solani isolates were the most common, twelve isolates of this group were selected and their phylogenetic relationships were studied. Of the three Clades of F. solani species complex, the isolates were placed in Clade 2 and 3. Only one isolate was found in Clade 2 whose properties matched those of F. brasiliense. The other isolates were classified in Clade 3 divided into two subgroups. In host range tests of F. solani isolates, none of the isolates was pathogenic on lentils, vetch and cowpea. A number of isolates caused root rot in chickpeas, soybeans, and potato tubers. F. lateritium, F. redolens and F. brasiliense are reported for the first time from Iran.