First report of Septoria ficariae on Ranunculus muricatus in Iran

In the framework of study on taxonomy of the genus of Septoria in Iran, we studied herbarium specimen of R. muricatus (IRAN 8006F) collected during 1990 from Golestan province (N Iran). A Septoria species was observed on the specimen with following morphological features: leaf lesions, brown, amphigenous, extended through the entire leaf and equally visible on both sides. Conidiomata amphigenous, mostly on lower side of the leaf, pycnidial, immersed, scattered on lesions, globose to slightly ovoid, 70–105 µm in diameter, dark brown, with a single apical ostiole. Condiomata wall 2–3 cells thick, outer layer dark brown, inner layer pale brown. Conidiogenous cells discrete, hyaline, ampulliform, formed from the inner cells of the conidiomatal wall. Conidia holoblastic, filiform, hyaline, straight or curved, 0–3 septate, septa often obscure, 23–48 × 1–1.5(–2) µm, with a truncate base, tapering to a subacute apex (Fig. 1). These morphological features and measurements were compatible with those of S. ficariae Desm. (Priest 2006). This fungus has been originally described on Ficaria ranunculoides Roth, but there are miscellaneous reports of its occurrence on Ranunculus spp. from Australia, China, Europe and Britain (Farr & Rossman 2018). Septoria ficariae has been described as a species with aseptate spores in some literature (i.e. Teterevnikova-Babayan 1987). However, our observation was in accordance with observation made by Priest (2006) and confirmed existence of septate conidia with obscure septa. Septoria ficariae is a new member for Iranian mycobiota and this is the first report of a Septoria species on the genus Ranunculus in Iran. Moreover, R. muricatus L. is reported here as a new host (Matrix nova) for S. ficariae. Ranunculus muricatus is an annual species distributed by Mediterranean region, Central Europe, Africa, Asia and also introduced Australia and America (Iranshahr et al. 1992). The plant is traditionally used by local practitioners for the treatment of various ailments and has been recently analyzed for its effective chemical compounds (Ali Khan et al. 2016). Material examined: Iran, Golestan province, Gorgan, Nahaarkhoraan, on R. muricatus, leg. Ershad, 15.5.1990 (IRAN 8006F).