Hermatomyces tectonae Doilom D.J. Bhat & K.D. Hyde sp. nov. Index Fungorum number: IF551965
Etymology: Name refers to the host genus Tectona on which the fungus was collected.
Holotype: MFLU 15–3437
Saprobic on dead twigs of T. grandis. Sexual morph:Undetermined. Asexual morph: Conidia on natural substrate, superficial, gregarious, scattered, black. Mycelium 1.5–3μm wide, hyphae, superficial, branched, anastomosing, a network of septate, brown. Conidiophores up to 80 μm long, 1.5–3.5 μm wide, micronematous to semi-macronematous, mononematous, straight or flexuous, septate, slightly constricted at the septa, pale brown, long, smooth, unbranched, arising from hyphae, indeterminate. Conidiogenous cells monoblastic, integrated, terminal, cylindrical, hyaline to subhyaline. Conidia dimorphic, thick-walled, smooth, of two types; Lenticular conidia: (23–)26–29(−33) μm diam. × (19–)23–25(−28) μm thick in lateral views (x = 27 × 23μm n = 50), muriform, central cells dark brown to black, subhyaline to pale brown at peripheral cells, with peripheral cells surrounding central, ellipsoidal, dark brown to black in the center, or dark brown to black at septa in the center, pale brown next to central cells, sub-hyaline to pale brown at thelower and upper cells, composed of 4–7 cells, arranged in 2–4 rows, mostly in 2 rows, septate, constricted at the septa. Cylindrical conidia: (27–)31–32(−35) μm diam. × (21–)23– 24(−27) μm wide in broadest part of lower cells μm, (x = 31 × 23μm, n= 20), with 2 columns composed of 3 cells, with black peripheral cells and dark brown upper cells, usually with two hyaline cells in the lower cells, subglobose, swollen at the lower part.
Culture characteristics: Conidia germinating on PDA within 24 h. Germ tubes produced around conidia. Colonies on MEA reaching 18–28 mm diam. after 7 days in the dark at 25 °C (x = 20.6 mm, n= 5), irregular in shape, undulate to lobate, flat or effuse to raise at the edge, convex with papillate surface on old mycelium plugs, aerial, medium sparse, grey (1D1) above, pastel grey (1C1) from below.
Habitat: Known to inhabit dead moist twigs of T. grandis (current study).
Known distribution: Thailand (current study).
Material examined: THAILAND, Chiang Rai Province, Muang District, Mae Fah Luang University campus grounds, on dead moist twigs of T. grandis, 1 October 2014, M. Doilom, (MFLU 15–3437, holotype), ex-type living culture MFLUCC 14–1140, MKT 170/1, ICMP 21177, GenBank Accession No: ITS: KU144917, LSU: KU764695, RPB2: KU712486, SSU: KU712465, TEF1: KU872757; ibid. (MFLU 15–3438, paratype), ex-paratype living culture MFLUCC 14–1141, MKT 170/2, GenBank Accession No: ITS:KU144918, LSU: KU764696, SSU: KU712466, TEF1: KU872758; ibid. (MFLU 15–3439, paratype), ex-paratype living culture MFLUCC 14–1142, MKT 170/3, ICMP 21178, GenBank Accession No: ITS:KU144919, LSU: KU764697, RPB2: KU712487, SSU: KU712467.
Notes: Hermatomyces tectonae is similar to H. thailandica and H. tucumanensis in the number of columns of cylindrical conidia being 2–3 cells, but conidia of H. tectonae are shorter and wider than H. tucumanensis. Conidia of H. tectonae are longer and wider than H. thailandica. The lenticular conidia in lateral view (thick) are wider than H. thailandica. Conidiophores of H. tectonae are longer than H. thailandica.
FIG Hermatomyces tectonae (MFLU 15–3437, holotype). a Mycelia and conidia on substrate.b Mycelia. c Conidiophore attached to mycelium. d–f Conidia with conidiophores. g Lenticular and cylindrical conidia. h, i Lateral views of lenticular conidia. j Lenticular conidia. k, l Cylindrical conidia. m Germinated conidia. n Colony on MEA after 7 days. Scale bars: a = 200 μm, b, c, e–g = 20 μm, d= 30 μm, h–i = 10 μm