Dendryphiella variabilis Iturrieta-Gonzalez , Dania Garcia & Gene

Iturrieta-Gonzalez, Isabel, Gene, Josepa, Guarro, Josep, Castaneda-Ruiz, Rafael F. & Garcia, Dania, 2018, Neodendryphiella, a novel genus of the Dictyosporiaceae (Pleosporales), MycoKeys 37, pp. 19-38 : 19

Dendryphiella variabilis Iturrieta-Gonzalez, Dania Garcia & Gene sp. nov. Fig. 5

Etymology.

Name refers to the variable number of septa in the conidia.

Type.

Cuba, from a dead leaf of a Lauraceous tree, 1996, R.F. Castañeda (holotype CBS H-23476; ex-type cultures CBS 584.96 = INIFAT C95/105-4 = MUCL 39840 = FMR 16563).

Description.

Mycelium superficial and immersed, composed of septate, branched, smooth to verruculose hyaline to pale brown hyphae, 1-3 μm wide. Conidiophores macronematous, mononematous, often arranged in loose fascicules, erect or slightly flexuous, branched, 1-8-septate, nodulose toward the apex, up to 143 μm long, 2-6 μm wide, brown, smooth to verruculose. Conidiogenous terminal and intercalary, sympodially extended towards the apex, with 1-5 pores surrounded by a thickened and darkened wall, clavate, 7-37 × 3 –6(– 7) μm. Ramoconidia (0 –)2– 3-septate, cylindrical to subcylindrical, with rounded ends, 16-27 × 5-6 μm, usually with 2 apical pores, conidial scars thickened and darkened. Conidia in short branched chains, with up to 5 conidia in the terminal unbranched part, (0 –)3(– 7)-septate, some constricted at the medial septum, pale brown, verruculose to verrucose, cylindrical or subcylindrical, with rounded ends, 6-44 × 4-6 μm, conidial scars often thickened and darkened. Sexual morph not observed.

Culture characteristics

(14 d at 25 °C). Colonies on PDA reaching 30-33 mm diam., slightly umbonate, flat towards the periphery, velvety, irregularly coloured yellowish-grey to olive brown (4B2/4D3) and brownish-grey to yellowish-brown (5F2/5F4), with irregular margin; reverse yellowish-brown (5F8) to black. On PCA attaining 48 mm diam., flat, granular to velvety, yellowish-brown (5F8), aerial mycelium scarce, undulate margin; reverse olive to greyish-yellow (3F4/3B4), with a pale yellow diffusible pigment. On OA reaching 58 mm diam., flat, slightly granular, blond to reddish-yellow (5C4/4A7), light yellow (4A4) at the periphery, aerial mycelium scarce, with a regular margin, with scarce pale brown exudate; reverse same colouration with the colony surface. On SNA attaining 40 mm diam., flat, slightly granular to velvety, yellowish-brown to grey (5F7/4B1), with fimbriate margin; reverse brownish-grey to white (5D2/1A1). On MEA reaching 32 mm diam., flat, cottony, yellowish-grey to olive (4B2/3F4), yellowish-grey (3B2) at the periphery, with regular margin; reverse dark green to white (30F8/1A1).

Cardinal temperature for growth.

Optimum 25 °C, maximum 30 °C, minimum 15 °C.

Distribution.

Cuba.

Notes.

Dendryphiella variabilis differs from D. paravinosa mainly by having longer conidia (up to 44 μm), which can have up to 7 septa. The conidia of D. paravinosa are up to 3-septate and measure (10−)24−27(−33) × (6−)7(−7.5) μm ( Crous et al. 2016). The only species of the genus reported with conidia up to 5-septate are D. eucalyptorum and D. vinosa , but they are smaller, measuring (19−)20−23(−25) × 5(−7) μm in the former ( Crous et al. 2014) and 13−39 × 4−8 μm in the latter ( Ellis 1971). The other closely related species to D. variabilis is D. fasciculata (Fig. 1), but it mainly differs by the presence of fasciculate conidiophores and 3-septate conidia ( Liu et al. 2017).