Tetraploa hainanensis X. Tang, Jayaward., R. Jeewon & J.C. Kang, 2023

Tang, Xia, Jeewon, Rajesh, Lu, Yong-Zhong, Alrefaei, Abdulwahed Fahad, Jayawardena, Ruvishika S., Xu, Rong-Ju, Ma, Jian, Chen, Xue-Mei & Kang, Ji-Chuan, 2023, Morphophylogenetic evidence reveals four new fungal species within Tetraplosphaeriaceae (Pleosporales, Ascomycota) from tropical and subtropical forest in China, MycoKeys 100, pp. 171-204 : 171

Tetraploa hainanensis X. Tang, Jayaward., R. Jeewon & J.C. Kang sp. nov.

Figs 6 , 7

Etymology.

The specific epithet ' hainanensis ' refers to the place where the fungus was collected, Hainan Province, China.

Holotype.

GZAAS 23-0603.

Description.

Saprobic on unidentified decaying wood in forest. Teleomorph morph Not observed. Anamorph Hyphomycetous. Colonies effuse, gregarious on host substrate, brown to dark brown. Mycelium semi-immersed or immersed, pale brown, branched, septate. Conidiophores absent. Conidiogenous cells integrated, monoblastic, determinate. Conidia 30-46 × 18-36 μm (x̅ = 38 × 27 μm, n = 20), cylindrical with obtuse ends, pale brown to brown, verrucose, composed of four columns of cells, sometimes five columns of cells, 4-5-septate in each column, smooth, mostly with four apical appendages, some with one or two or five appendages. Appendages 52-209 × 3-6 μm (x̅ = 140 × 4 μm, n = 20) cylindrical, solitary, unbranched, guttulate, septate, wide at the base, divergent, pale brown to brown, 5-16-septate, straight or slightly flexuous, smooth-walled.

Culture characteristics.

Conidia germinated from both ends on PDA and incubated at room temperature (25 ˚C). Colonies circular, cottony, flat, slightly grey with an entire margin, contain a circular white mycelium in the centre. The reverse side is a pale brown in the centre that gradually extends outwards while the colour changes to pale grey, with a brown margin and no pigment.

Material examined.

China, Hainan Province, Wuzhishan City, Wuzhishan National Nature Reserve , on unidentified decaying wood, 25 September 2021, Zili Li, WZS59 (GZAAS 23-0603, holotype), ex-type culture GZCC 23-0601; WZS66.2 (GZAAS 23-0604, paratype), culture GZCC 23-0602 .

Notes.

Tetraploa hainanensis is morphologically similar to T. pseudoaristata . However, Tetraploa hainanensis can be distinguished from T. pseudoaristata in having larger conidia (30.5-46 × 18-36 μm vs. 22-31 × 15-20 µm) with four columns of cells, sometimes five columns of cells, and longer appendages (52-209 × 3-6 μm vs. 23-107 × 2-5 μm), commonly four in number, sometimes five. Based on the phylogenetic analysis, two of our Tetraploa collections which share similar morphology clustered together with high support (ML = 100, and BPP = 1 (Fig. 1 )). The base pair differences between the two strains were: LSU = 0.1% (1/806), ITS = 0% (0/516), and tub2 = 0% (1/633), respectively. Therefore, we considered them as the same species according to the guidelines for species delineation proposed by Jeewon and Hyde (2016). Tetraploa hainanensis forms a distinct lineage but close to T. yakushimensis and T. tetraploa . However, Tetraploa hainanensis differs from T. yakushimensis by having four or five columns and appendages, while T. yakushimensis has only four columns and appendages; Tetraploa hainanensis differs from T. tetraploa in having four or five columns and shorter appendages (52-209 × 3-6 μm vs. 263-350 × 2-3 μm), while T. tetraploa has only four columns and slender appendages. The comparison of pairwise nucleotide showed that Tetraploa hainanensis is different from T. yakushimensis in 31/620 bp (3%) in LSU, 7/814 (0.98%) in ITS, and 87/450 (19%) in tub2 and Tetraploa hainanensis is different from T. tetraploa in 31/620 bp (3%) in LSU, 7/814 (0.98%) in ITS, and 87/450 (19%) in tub2. Based on the combination of morphological characters and multigene phylogeny, we describe Tetraploa hainanensis herein as a distinct species according to the guidelines of Jeewon and Hyde (2016) and Chethana et al. (2021).

Figures

Figure 1. Phylogenetic construction of Tetraplosphaeriaceae using RAxML-based maximum likelihood analysis of a combined LSU, ITS, SSU, and tub 2 DNA sequence dataset. Bootstrap support values for maximum likelihood (ML) equal to or greater than 70 % and Bayesian posterior probabilities (PP) equal to or greater than 0.95 PP are shown above the nodes. The tree is rooted with Amniculicola immersa (CBS 123083) and A. parva (CBS 123092). Newly generated strains are in red, and the type strains are indicated using " T " in superscript.

Figure 6. Tetraploa hainanensis (GZAAS 23 - 0603, holotype) a, b colonies on natural substrates c-n conidia bearing 1 - 5 appendages o germinating conidium p colony on PDA (from reverse) q colony on PDA (from front). Scale bars 20 μm (c); 50 μm (d-g); 100 μm (h-o).

Figure 7. Tetraploa hainanensis (GZAAS 23 - 0604, paratype) a colonies on decay wood b, c colonies on natural substrates d-p conidia bearing 1 - 4 appendages q germinating conidium r colony on PDA (from front) s colony on PDA (from reverse). Scale bars: 20 μm (d-g); 100 μm (h-l, o, q); 50 μm (m, n, p).