Escovopsis clavatus Q.V. Montoya, M.J.S. Martiarena, D.A. Polezel, S. Kakazu & A. Rodrigues

Montoya, Quimi Vidaurre, Martiarena, Maria Jesus Sutta, Danilo Augusto Polezel,, akazu, Sergio & Rodrigues, Andre, 2019, More pieces to a huge puzzle: Two new Escovopsis species from fungus gardens of attine ants, MycoKeys 46, pp. 97-118 : 101-102

Escovopsis clavatus Q.V. Montoya, M.J.S. Martiarena, D.A. Polezel, S. Kakazu & A. Rodrigues sp. nov. Figs 1, 2, 3

Etymology.

“clavatus” in reference to the predominantly clavate shape of vesicles.

Typification.

BRAZIL. Santa Catarina, Florianópolis, (27°44'39.6"S, 48°31'10.14"W), elev. 46 m, fungus garden, 08, 2015. A. Rodrigues. Holotype: CBS H-23845 (dried culture on PDA). Ex-type strain LESF 853 (= CBS 145326).

Sequences.

ITS (MH715096), tef1 (MH724270) and LSU (MH715110).

Description.

Colonies grow only at 20 and 25 °C (Fig. 1). At both temperatures, growth starts on the third day on CMD, CYA, MA2%, MEA, OA, PCA, PDA; and on the sixth day on SNA. Colonies have floccose aerial mycelia with a pale-brown colour after seven days. Faster growth was observed on MA2% and heavy sporulation was identified on MA2%, PDA and OA. At 20 °C, colonies reached 0.5-0.7 cm, 1.5-2.5 cm and 0.5-1 cm on CMD, CYA and SNA, respectively. At this temperature, colonies reached the edge of the plate after 10 days on MA2% and PCA; after 12 days on OA and MEA; and after 14 days on PDA and CYA. At 25 °C, colonies reach 2 cm, 3-3.2 cm and 2 cm on CMD, CYA and SNA, respectively, after 14 days. At this temperature, colonies reached the plate edge after seven days on OA and PCA; and after 10 days on MA2%, MEA and PDA. Concentric rings were observed only on PCA at 20 °C (Fig. 1). No pustule-like structures were observed.

Conidiophores arising from aerial hypha alternated or opposite (Fig. 2A), with the main axis of 50-780 μm in length, some without branching and often with 1-2 levels of branching (Figs 2A, E, 3A, E). Branches arise from the main axis of the conidiophore in an alternated or opposite pattern, with a septum near to the central axis and before the vesicle, usually with 1-2 branches at each branching point (16-138 μm long) or 2-4 branches arising from swollen cells (28-35 μm long), mostly forming angles less than 90° and less frequently right angles, usually straight and sometimes slightly curved up or down. Each branch terminates in a vesicle, with 1-8 fertile heads per conidiophore. Swollen cells are present in 15% of the total of conidiophores examined (Figs 2C, D, 3E) and can measure 10-18 μm long × 7-9 μm wide. Vesicles with only a septum at the base, in various shapes: globose (8%), subglobose (24%), broadly ellipsoidal / clavate (33%), ellipsoidal (27%), cylindrical (8%) (Figs 2 E–G and 3 F–G); and reaching 9-27 μm long × 7-20 μm wide. Phialides lageniform formed on vesicles (Fig. 3H), with 5-8 μm in total length, elongated base (0.5-1.5 μm × 0.5-1 μm), followed by a swollen section (1.5-2.5 μm × 1-3 μm) and a thin neck (1.5-4 μm × 0.5 μm). Conidia with 1.5 μm– 2.5 μm long × 0.5 μm– 1.5 μm wide, in various shapes: broadly ellipsoidal (5%), ellipsoidal (43.3%), cylindrical (51.7%); brown, with smooth and slightly thickened walls and in chains (Figs 2H, 3I).

Habitat.

Isolated from fungus gardens of Apterostigma sp.

Additional specimens examined.

BRAZIL. Santa Catarina, Florianópolis, (27°44'38.94"S, 48°31'9.3"W), elev. 32 m, fungus garden, 08, 2015. A. Rodrigues. LESF 854 (ITS - MH715097, tef1 - MH724271 and LSU - MH715111). Santa Catarina, Florianópolis, (27°44'39.49"S, 48°31'9.72"W), elev. 38 m, fungus garden, 08, 2015. A. Rodrigues. LESF 855 (ITS - MH71509, tef1 - MH724272 and LSU - MH715112).

Notes.

Escovopsis clavatus is phylogenetically closely related to E. multiformis and its most distinctive characters are its growth temperatures, the conidiophore branching and the swollen cells. It grows at 20 and 25 °C; nevertheless, E. multiformis grows at 10, 20, 25 and 30 °C. The conidiophore of E. clavatus is larger and more branched than the conidiophore of E. multiformis . In addition, the swollen cells of E. clavatus are less frequent and shorter than in E. multiformis . The character distinguishing E. clavatus from other species of Escovopsis is the swollen cell on the conidiophores and because it is phylogenetically placed in a distinct clade.