Identification and pathogenicity of fungal species associated with leaf spot of mango trees in the south of Iran

During the survey of mango (Mangifera indica, Anacardiaceae) trees in Sistan and Baluchestan, Hormozgan, and Kerman Provinces, the occurrence of leaf spot diseases was observed. Symptomatic samples were collected and subsequently transferred to the laboratory for the purpose of isolating the causal agents. After surface sterilization of selected leaf tissues, small leaf pieces were transferred to potato dextrose agar (PDA). In order to achieve purification, single spore or hyphal tip methods were used. Based on morphological criteria and analyzing data from the ITS-rDNA and glyceraldehyde ۳-phosphate dehydrogenase (gpd) gene regions, ۱۱۸ isolates belonging to Alternaria alternata, Curvularia hawiiensis, and Exserohilum rostratum species were identified. Pathogenicity test was carried out by using detached leaf assay on leaf pieces of mango. After seven days, necrotic lesions were observed on inoculated leaves and fungal isolates were re-isolated and identified to confirm Koch's postulates. To the best of our knowledge, this study is the first report of C. hawaiiensis and E. rostratum as the causal agents of leaf spot on mango trees in Iran.

Keywords:

Hyphomycetous fungi , leaf spot , mango , South of Iran