Diaporthe rumicicola

Diaporthe rumicicola Manawasinghe, Camporesi & K.D. Hyde, in Hyde et al., Fungal Diversity: 10.1007/s13225-019-00429-2, [138] (2019)

Index Fungorum number: IF 555379; Facesofungi number: FoF 04940

Etymology: Name reflects the host genus.

Holotype: MFLU 18-0739.

Saprobic on dead stems of woody plants. Sexual morph: Undetermined. Asexual morph: Conidiomata on host pycnidial, 98–280 μm diam. (x̄ = 208 μm, n = 10), ampulliform, scattered, immersed, ostiolate, with elongate black neck. Pycnidial wall comprising 2–3 layers, heavily pigmented, thick-walled, comprising dark brown cells of textura angularis, with lighter cells towards the inside, with inner layer composed of 2–5 layers, hyaline, thin-walled cells of textura angularis. Conidiophores on host reduced to conidiogenous cells. Pycnidia in culture black, immersed, solitary or merged, exudated. Paraphyses observed on culture. Conidiogenous cells enteroblastic with percurrent annellations, integrated, clustered, hyaline, smooth-walled. Alpha conidia, on host 3–5 9 2–3 μm (x̄ = 3.5 × 2.5 μm, n = 30), hyaline, smooth-walled, mono or bi-guttulate. Beta conidia not observed.

Culture characteristics: Colonies on PDA 50 mm diam., after 7 days at 25 °C, cream to white cottony mycelium, irregular and lobate at the margins, white at the centre; reverse yellowish and concentric lines on conidial formation can be observed when colony getting old.

Material examined: ITALY, near Castrocaro Terme (province of Forlı´-Cesena), on dead aerial stem of Rumex sp. (Polygonaceae), 19 February 2018, Camporesi Erio IT (MFLU 18-0739, holotype), ex-type living culture (MFLUCC 18-1566, JZB320005).

GenBank: ITS: MH84623, TEF1-a: MK049554, TUB2: MK049555.

Notes: Diaporthe rumicicola was isolated from a dead branch of Rumex sp. from Forı´-Cesena of Italy. Morphologically, this species is similar to genus Diaporthe, and the combined gene sequence analysis of ITS, TEF1-a, CAL and TUB2 genes placed the taxon in Diaporthe. The current species develop a sister clade with Diaporthe foeniculina with 100% bootstrap value in ML analysis and 1.0 Bayesian probabilities in Bayesian analysis (Hyde et al. 2019). Morphologically the current species is differing with developing smaller alpha conidia (3.5 9 2.4 μm) compared to D. foeniculina (8.5–9 × 2.3–2.5 μm) (Udayanga et al. 2014). In addition to that this is the first time that Diaporthe species recorded on Rumex sp. (Farr and Rossman 2019).