Polyplosphaeria 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

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

Figs 3 , 4

Etymology.

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

Holotype.

GZAAS 23-0601

Description.

Saprobic on unidentified decaying wood in the forest. Teleomorph not observed. Anamorph Hyphomycetous. Colonies effuse, gregarious on host substrate, brown to blackish brown. Mycelium semi-immersed or immersed, dark brown, branched, septate. Conidiophores absent. Conidiogenous cells indistinguishable from creeping hyphae, integrated, monoblastic, determinate. Conidia 49-134.5 × 52-90.5 μm (x̅ = 86 × 71 μm, n = 20), globose, subglobose, obconical, broadly ellipsoidal to broadly pyriform, variable in shape, sometimes with thin peel on the outer wall of conidia, internally filled with a mass of hyaline, solitary, brown to dark brown, smooth. Appendages 36-58 × 3-5.5 μm (x̅ = 44.5 × 4 μm, n = 20), cylindrical, solitary, straight or flexuous, unbranched and almost hyaline at the apex, 0-4-septate, smooth, round at apex, pervasive.

Culture characteristics.

Conidia germinated from both ends on PDA and incubated at room temperature (25 ˚C). Colonies circular, cottony, flat, olivaceous with a slightly grey entire margin. The reverse side is an olive drab, which gradually extends outwards to form a deep colour ring in the centre with a pale grey margin and no pigment.

Material examined.

China, Hainan Province, Wuzhishan City, Wuzhishan National Nature Reserve , on unidentified decaying wood, 25 September 2021, Zili Li, WZS27 (GZAAS 23-0601, holotype), ex-type culture GZCC 23-0599; WZS31 (GZAAS 23-0602, paratype), culture GZCC 23-0600 .

Notes.

Based on the phylogenetic analysis (Fig. 1 ), two of our Polyplosphaeria collections share similar morphology and clustered together with high support (ML = 100, and BPP = 1). The base pair differences between the two strains (GZCC 23-0599 and GZCC 23-0600) were: LSU = 0.2% (2/834), ITS = 0.1% (1/840), respectively, therefore, we considered them as the same species according to the guidelines for species delineation proposed by Jeewon and Hyde (2016). The phylogenetic result (Fig. 1 ) showed that Polyplosphaeria hainanensis is sister to Po. nabanheensis within Polyplosphaeria . Based on the comparison of the morphological characters with other species in Polyplosphaeria , our collection can be distinct in having obconical, broadly ellipsoidal to broadly pyriform, variable conidial shape (without verrucose at the base) and pervasive appendages. The comparison of pairwise nucleotides showed that Polyplosphaeria hainanensis is different from Po. nabanheensis in 24/826 bp (3%) in LSU, 20/758 (2.6%) in SSU, 17/472 (3.6%) in ITS and 16/344 (5%) in tub2. Thus, we describe Polyplosphaeria hainanensis herein as a novel species in Polyplosphaeria 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 3. Polyplosphaeria hainanensis (GZAAS 23 - 0601, holotype) a colonies on decay wood b colonies on natural substrates c-m conidia bearing appendages n germinating conidium o colony on PDA (from front) p colony on PDA (from reverse). Scale bars: 50 μm (c-n).

Figure 4. Polyplosphaeria hainanensis (GZAAS 23 - 0602, paratype) a colonies on decay wood b, c colonies on natural substrates d-o conidia bearing appendages p colony on PDA (from front) q colony on PDA (from reverse). Scale bars: 100 μm (d-i, k-m); 50 μm (j, n, o).