Dictyosporium tubulatum J. Yang, K.D. Hyde & Z.Y. Liu

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

publication ID

http://dx.doi.org/10.3897/mycokeys.36.27051

persistent identifier

http://treatment.plazi.org/id/9B07F4FE-B03A-9019-EC60-16703FF072C6

treatment provided by

MycoKeys by Pensoft

scientific name

Dictyosporium tubulatum J. Yang, K.D. Hyde & Z.Y. Liu
status

sp. nov.

Dictyosporium tubulatum J. Yang, K.D. Hyde & Z.Y. Liu  sp. nov. Figure 5

Etymology.

Referring to the tubular conidial appendages.

Description.

Saprobic on decaying plant substrates. Asexual morph: Colonies punctiform, sporodochial, scattered, dark brown to 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, 6.5-15 × 3.5-6 μm, sometimes reduced to conidiogenous cells. Conidiogenous cells  monoblastic, integrated, terminal, determinate, hyaline to pale brown. Conidia  acrogenous, solitary, cheiroid, smooth-walled, complanate, yellowish-brown to medium brown, mostly consisting of four arms closely compact with side arms lower than middle arms, rarely with five arms, 5-7-euseptate in each arm, guttulate, (22 –)29–35(– 38) × (14 –)17–19(– 22) μm (x¯ = 32.5 × 18 μm, n = 40), with hyaline, tubular, elongated appendages which are 19-24 × 3.5-7 μm and mostly attached at the apical part of two outer arms. Sexual morph: Undetermined.

Cultural characteristics.

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

Material examined.

THAILAND. Prachuap Khiri Khan Province, near 12°30.19'N, 99°31.35'E, on decaying wood submerged in a freshwater stream, 25 December 2014, J. van Strien, Site 5-11-1 (MFLU 15-1166 holotype, HKAS 102136 isotype), ex-type living culture MFLUCC 15-0631; ibid. 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 22-2 (MFLU 18-1044, HKAS 102137 paratype), living culture MFLUCC 17-2056.

Notes.

Phylogenetic analyses showed that Dictyosporium tubulatum  nested in Dictyosporium  and sister to D. nigroapice  . Dictyosporium tubulatum  morphologically resembles D. alatum  Emden, D. canisporum  L. Cai & K.D. Hyde and D. thailandicum  D’ souza, D.J. Bhat & K.D. Hyde in conidial ontogeny and conidial shape, colour and appendages. Dictyosporium tubulatum  differs from the three species in the number of conidial cell rows. There are mostly four conidial columns in D. tubulatum  while mostly five columns in the others. Dictyosporium tubulatum  has smaller conidia (25-38 × 14-22 μm) than those in D. canisporum  (32.5-47.5 × 20-25 μm) but has similar conidial size with D. alatum  (26-32 × 15-24 μm) and D. thailandicum  (15.4-34.5 × 14.5-20.6 μm) ( Cai et al. 2003, Liu et al. 2015). Based on the molecular phylogeny, D. tubulatum  is distinct from D. thailandicum  and D. alatum  . Unfortunately, molecular data are unavailable for D. canisporum  .