Alternaria species associated with Quercus brantii in Zagros forests of Fars province, Iran

Persian oak is the most important forest tree in Fars province (Iran). In order to identify the composition of Alternaria species associated with healthy and declined Persian oak trees in Fars Province, Iran, fungal isolates were recovered from twigs, trunks and leaves of healthy and declining Persian oak trees from early September to late March 2021-2022. Fungal species were identified based on both morphological and as well as molecular characteristics of the DNA sequence data of the glyceraldehyde 3-phosphate dehydrogenase (GAPDH) and plasma membrane ATPase genes. In total, 29 Alternaria isolates were obtained, which were identified as Alternaria alternata, Alternaria consortialis and Alternaria chlamydospora. Alternaria alternata showed the highest frequency approximately 51.72% and were isolated from both healthy and declining oak trees. Alternaria chlamydospora and A. consortialis were obtained only from healthy oak trees without declining symptoms with 41.38% and 6.89% frequencies,, respectively. Pathogenicity tests were conducted using all isolates in three replicates. Inoculation of different Alternaria alternata, Alternaria consortialis and Alternaria chlamydospora isolates on Persian oak seedlings did not show any symptoms after 60 days in greenhouse conditions. This is a new report of Alternaria species including A. alternata, A. consortialis and A. chlamydospora as endophytic fungi on Persian oak tree in Fars province of Iran.