Dictyosporium tratense J. Yang & K.D. Hyde

Yang, Jing, Liu, Jian-Kui, Hyde, Kevin D., Jones, E. B. Gareth & Liu, Zuo-Yi, 2018, New species in Dictyosporium, new combinations in Dictyocheirospora and an updated backbone tree for Dictyosporiaceae, MycoKeys 36, pp. 83-105 : 83

Dictyosporium tratense J. Yang & K.D. Hyde sp. nov. Figure 6

Etymology.

Referring to the collecting site in Trat province, Thailand.

Description.

Saprobic> on decaying plant substrates. Asexual morph: Colonies punctiform, sporodochial, scattered, black, glistening. Mycelium mostly immersed, composed of smooth, septate, branched, hyaline to pale brown hyphae. Conidiophores micronematous, mononematous, septate, cylindrical, hyaline to pale brown, smooth-walled, sometimes reduced to conidiogenous cells. Conidiogenous cells monoblastic, integrated, terminal, determinate, hyaline to pale brown. Conidia (40 –)43–54(– 57) × (20 –)23–32(– 36) μm (x¯ = 49.5 × 26 μm, n = 40), acrogenous, solitary, cheiroid, smooth-walled, complanate, yellowish-brown to light brown, consisting of 39-68 cells arranged in 4-6 (mostly 5) closely compact columns, 9-11-euseptate in each column, guttulate; the inner columns nested within the outer columns, the outer columns derived from the basal cell of the conidium; the intermediate columns are derived from the first or second cell of the outer columns; the inner columns derived from the first or second cell of the intermediate columns; usually with 2-3 central columns longest and of equal length, 2-3 peripheral columns shorter and of equal length; sometimes with hyaline globose appendages at the apical cells of outer columns with hyaline cloud-shaped mucilaginous sheath. Sexual morph: Undetermined.

Cultural characteristics.

Conidia germinating on PDA within 24 h and germ tubes produced from basal cell. Colonies on MEA reaching 5-10 mm diam. in a week at 25 °C, in natural light, circular, with fluffy, dense, pale yellow mycelium in the middle and sparse mycelium in the outer ring on the surface with irregular margin; in reverse, dark yellow to brown in the middle and pale yellow at the margin.

Material examined.

THAILAND. Trat Province, Amphoe Ko Chang, 12°08'N, 102°38'E, on decaying wood submerged in a freshwater stream, 27 April 2017, Y.Z. Lu, YJT 6-2 (MFLU 18-1042 holotype, HKAS 102133 isotype), ex-type living culture MFLUCC 17-2052 (Additional SSU sequence GenBank MH381761).

Notes.

Phylogenetic analyses indicated Dictyosporium tratense nested within Dictyosporium and close to D. wuyiense . It is distinguished from the other species in the genus in having a mucilaginous sheath. Morphologically, D. tratense is most comparable to D. elegans in conidial colour and shape, but conidia of the new taxon (40-57 × 20-36 μm) are smaller than those of D. elegans (40-80 × 24-36 μm) ( Goh et al. 1999).