First report of Circinella muscae for funga of Iran

During the study of fungal taxa in different regions of Markazi province (Iran) in spring of 2022, a fungal isolate with similar characteristics of Circinella Tiegh. & G. Le Monn. was obtained from the leaf spot symptom of Ficus altissima Blume. Based on the combined morphological characteristics and the sequence data of the ITS-nrDNA regions, recovered isolate (UTR29) was identified as C. muscae (Sorokin) Berl. & De Toni. Sporangiophores arising from the substrate or aerial mycelia, at first colorless then becoming pale brown, 6–11 μm in diam., erect, growing indefinitely, branching sympodial; branches sometimes 2–3- septate, at the end, bearing a single fertile sporangium, two fertile sporangia or a single fertile sporangium and a sterile spine; spines sterile, pale brown and cut off by a septum; sporangia diverse in size, multispored, globose to slightly dorsiventrally, with persistent wall, smooth, breaking, at first hyaline then becoming brownish yellow to gray with age, 30–61 × 29–58 μm in size; collumellae mostly hyaline, rarely light brown, diverse in shape, pyriform, oval, conical, subglobose, 18–30 × 15–28 μm in size; sporangiospores globose to oval, aseptate, grayish brown in color, black color in mass (inside of the sporangium), smooth, 3–7 × 3–6 μm in size. The nuclear ITS-rDNA of the isolate was amplified by ITS1/ITS4 primer pairs and the PCR product was sequenced. The resulting sequence was deposited in the GenBank (NCBI) with accession number of OQ550282. In the ML phylogenetic tree, isolate UTR29 was clustered with the other Circinella species with a bootstrap support of 100%. In addition, UTR29 was grouped with the other isolates of C. muscae (KF805762, KF805763 and MN431502) with a bootstrap support of 80%. Based on the bibliography, C. muscae is a new taxon for funga of Iran and Ficus altissima Blume is a new host (matrix nova) for C. circinans in the world. Living culture of isolate UTR29 was deposited in Agricultural Biotechnology Research Institute of Iran Culture Collection (Karaj, Iran) under accession number ABRIICC 10371.