Hermatomyces turbinatus G.C. Ren & K.D. Hyde, 2021

Ren, Guang-Cong, Wanasinghe, Dhanushka N., Monkai, Jutamart, Mortimer, Peter E., Hyde, Kevin D., Xu, Jian-Chu, Pang, Aimin & Gui, Heng, 2021, Novel saprobic Hermatomyces species (Hermatomycetaceae, Pleosporales) from China (Yunnan Province) and Thailand, MycoKeys 82, pp. 57-79 : 57

Hermatomyces turbinatus G.C. Ren & K.D. Hyde sp. nov.

Figure 2

Etymology.

Referring to the turbinate shape of the conidia.

Holotype.

HKAS 112724.

Description.

Saprobic on woody litter of Dipterocarpus sp. ( Dipterocarpaceae ) Sexual morph Undetermined. Asexual morph Colonies on natural substrate forming sporodochial conidiomata, superficial, scattered, small groups, circular or oval, sterile mycelial outer zone enclosing a black-brown velvety margin, sparse, black sporulating center, shiny, glistening, circular or oval, conidia readily liberated when agitated. Mycelium superficial, branched, septate, hyaline to pale brown, 2-3 μm wide. Conidiophores 6-8 × 2-3 μm, micronematous, straight or flexuous, smooth, short, pale brown. Conidiogenous cells 3-5 × 2-3 μm, monoblastic, integrated, terminal, determinate, often arising directly on the superficial mycelium, subsphaerical, ovoid or ampulliform, hyaline to pale brown, smooth finely verruculose. Conidia dimorphic, solitary, smooth-walled. Lenticular conidia 24-30 × 17-21 μm (x = 27 × 20 μm, n = 20), 12-15 μm thick, thick-walled, circular to oval in front view, smooth, solitary, muriform, central cells dark brown to black, peripheral cells hyaline to pale brown, forming a weakly ring, sometimes slightly constricted at septa, obovoid or oblong in lateral view, arranged in 2 rows, a row of composed of 4-6 cells, end cells pale brown to hyaline, middle cells dark brown. Turbinate conidia turbinate, pyriform, 27-36 μm in length, 19-28 µm wide in broadest part of lower cells, (x = 32 × 23 μm, n = 20), asymmetrical with the upper cells smaller than lower cells, thick-walled, smooth, septate, constricted distinct at septa, consisting of two columns with two septa composed of 2-3 rectangular to globose cells in each column, usually upper part of terminal cells dark brown, becoming hyaline towards the lower side, two cells hyaline in the lower cells swollen with oil globules.

Known host and distribution.

Dipterocarpus sp. (Thailand).

Culture characteristics.

Colonies on PDA, reaching 30-40 mm diam., after 3 weeks at 25-30 °C, circular, convex with papillate and radially furrowed at the center, rough, labate, crenate edge, fluffy, dense, gray black, in reverse darkens at the center, pale brown to gray at edge.

Material examined.

Thailand, Tak Province. Ban Na Sam Ngao District , on woody litter of Dipterocarpus sp. ( Dipterocarpaceae ), 22 August 2019, G. C. Ren, TSY04 (HKAS 112724, holotype), ex-type living culture, MFLUCC 21-0038 .

Notes.

Hermatomyces turbinatus is introduced as a new species based on its distinct morphology, which is supported by phylogenetic analyses. In the phylogenetic analyses, H. turbinatus is distinct from extant species in this genus and formed a sister clade to H. nabanheensis with strong support (94% ML, 91% MP, 1.00 PP; Fig. 1 ). Hermatomyces turbinatus differs from H. nabanheensis in having turbinate conidia with two columns, while H. nabanheensis has cylindrical conidia with one or two columns. Hermatomyces turbinatus has two conidial types, and its lenticular conidia are similar to H. tectonae in shape and size. However, the turbinate conidia of H. turbinatus have 2 columns of 2-3 cells in each column, while the turbinate conidia of H. tectonae have 2 columns of 3 cells in each column. We also compared the morphological characters of H. turbinatus to other species of Hermatomyces (Table 2 ). Despite no molecular data being available for the three species viz. H. dimorphus , H. uniseriatus and H. truncates , H. turbinatus nonetheless differs from these species in conidial characteristics (Table 2 ).

Figures

Figure 1. Phylogenetic RAxML tree based on analysis of a combined LSU, ITS, tub 2, tef 1 - α and rpb 2 and dataset. Bootstrap support values for ML and MP equal to or higher than 75 % and Bayesian PP equal to or greater than 0.95 are shown at nodes. Hyphens (--) represent support values less than 75 % / 0.95 BYPP. The ex-type strains are in bold and the new isolate in this study is in blue bold. The tree is rooted with Anteaglonium globosum (ANM 925.2) and A. parvulum (MFLUCC 14 - 0821). The scale bar represents the expected number of nucleotide substitutions per site.

Figure 2. Hermatomyces turbinatus (HKAS 112724, holotype) a, b sporodochia on natural substrate c vertical section of sporodochium d conidiophores and conidiogenous cells e-h turbinate conidia i turbinate and mature lenticular conidia j-m mature lenticular conidia n germinated conidium o, p culture characters on PDA. Scale bars: 30 μm (c); 20 μm (d-n); 30 mm (o, p).