Distoseptispora hainanensis X.M. Chen & Y.Z. Lu, 2024

Chen, Xue-Mei, Tang, Xia, Ma, Jian, Liu, Ning-Guo, Tibpromma, Saowaluck, Karunarathna, Samantha C., Xiao, Yuan-Pin & Lu, Yong-Zhong, 2024, Identification of two new species and a new host record of Distoseptispora (Distoseptisporaceae, Distoseptisporales, Sordariomycetes) from terrestrial and freshwater habitats in Southern China, MycoKeys 102, pp. 83-105 : 83

Distoseptispora hainanensis X.M. Chen & Y.Z. Lu sp. nov.

Fig. 2

Etymology.

The epithet refers to the location "Hainan Province" where the holotype was collected.

Holotype.

GZAAS 22-2047.

Description.

Saprobic on decaying wood in terrestrial habitat. Sexual morph: Undetermined. Asexual morph: Colonies on natural substrate superficial, effuse, dark brown, and hairy. Mycelium mostly immersed, composed of branched, septate, brown to dark brown, smooth hyphae. Conidiophores 70-130 × 5-8.5 μm (x- = 103 × 7 μm, n = 20), macronematous, mononematous, erect, solitary, straight or slightly flexuous, brown to dark brown, paler towards the apex, cylindrical, 4-6-septate, slightly constricted and darkened at septa, unbranched, thick-walled. Conidiogenous cells 6-13 × 3.5-6.5 μm (x- = 10 × 5 μm, n = 20), holoblastic, monoblastic, integrated, terminal, indeterminate, cylindrical, slightly tapering towards the apex, brown, percurrent. Conidia 44-117 μm × 9-18.5 μm (x- = 90 × 14 μm, n = 20), acrogenous, solitary, obclavate or obpyriform, rostrate, truncate at the base, straight or slightly curved, up to 22-distoseptate, slightly constricted at septa, brown, verrucose.

Culture characteristics.

Colonies grown on PDA circular, dense, fluffy, with raised center and lobate edge, pale gray in the center, grayish brown in the outer ring from the front view, dark brown in the center, and blackish brown in the outer ring from the reverse view.

Material examined.

China, Hainan Province, on unidentified decaying wood, 15 May 2021, Xia Tang, HN 02 (GZAAS 22-2047, holotype), ex-type living culture, GZCC 22-2047 .

Notes.

Morphologically, Distoseptispora hainanensis is similar to D. effusa L.L. Liu & Z.Y. Liu in having macronematous conidiophores, monoblastic conidiogenous cells, and acrogenous, obclavate, rostrate conidia ( Yang et al. 2021). However, conidia of D. hainanensis are up to 22-distoseptate, whereas those of D. effusa are only 4-9-distoseptate. In the phylogenetic analyses, D. hainanensis formed a distinct clade sister to D. multiseptata Jiao Yang & K.D. Hyde with 98% ML, 1 PP, and 93% MP statistical support (Fig. 1 ). Distoseptispora hainanensis differs from D. multiseptata in having brown, longer conidiophores (70-130 μm vs. 23-65 µm) and obclavate or obpyriform, brown, verrucose, smaller conidia (44-117 μm vs. up to 290 µm) ( Hyde et al. 2016). Comparing DNA sequence data, D. hainanensis diverges from D. multiseptata (MFLUCC 15-0609) in the ITS by 21/552 bp (3.8% difference), in the LSU by 1/812 bp (0.01% difference), in tef 1-α by 33/912 bp (3.6% difference), and no data is available for rpb 2 of D. multiseptata (MFLUCC 15-0609) in GenBank. Hence, the novel species, D. hainanensis , is introduced, following the guidelines of Jeewon and Hyde (2016) and Chethana et al. (2021).

Figures

Figure 1. Phylogenetic tree generated from ML analysis based on a combination of LSU, ITS, tef 1 - a, and rpb 2 sequence data. Bootstrap support values of ML and MP equal to or greater than 75 %, and PP value equal to or greater than 0.95 are given near the nodes as ML / PP / MP. The tree is rooted with Aquapteridospora aquatica (MFLUCC 17 - 2371). Ex-type strains are indicated by the superscript T. The new collections are in bold red text.

Figure 2. Distoseptispora hainanensis (GZAAS 22 - 2047, holotype) a, b colonies on substrate c-e conidiophores and conidia f-h conidiogenous cells bearing conidia i, j conidiophores k-q conidia r, s colony on PDA (r from front s from reverse). Scale bars: 50 μm (c, d, f-j, l-q); 30 μm (e, k).