Tetraploa lignicola J.N. Li, R.J. Xu & Y.A. Zhu, 2023

Li, Jia-Ning, Wang, Shi-Yu, Xu, Rong-Ju, Xu, Ke, Ma, Chun-Hua, Zhao, Qi & Zhu, Ying-An, 2023, Tetraploa lignicola, a new freshwater fungal species from Yunnan Province, China, Phytotaxa 629 (3), pp. 245-254 : 248-250

Tetraploa lignicola J.N. Li, R.J. Xu & Y.A. Zhu , sp. nov. ( FIGURE 2 )

Index Fungorum number: IF900231; Facesoffungi number: FoF 14353

Etymology:— Referring to the fungus dwelling on wood.

Holotype:— HKAS 128978.

Saprobic on submerged decaying wood in a freshwater stream. Sexual morph: Undetermined. Asexual morph: Hyphomycetous. Colonies effuse, pale brown to greyish brown, hairy. Mycelium partly superficial, partly immersed in the substrate, consisting of branched, septate, brown to dark brown hyphae. Conidiophores indistinct, solitary, unbranched, brown smooth. Conidiogenous cells integrated, monoblastic, terminal, pale brown, and cylindrical. Conidia 38–53 × 22–39 μm (= 43 × 28 μm, n = 14), solitary, septate, verrucose, cylindrical, brown, composed of four columns of cells, 3-septate in each column, with four apical appendages. Appendages 93–127 × 5–7 (= 109 × 6 μm, n = 14), straight or slightly flexuous, unbranched, smooth, brown to pale brown, hyaline towards the apex, 5–10- septate, slightly tapering toward the apex.

Culture characteristics: Conidia germinated on PDA within 24 h. Colonies on PDA growing up to 25 mm in diameter after two weeks at room temperature in natural light, colonies on PDA irregular, smooth surface with undulate edge; colonies from above brown to pale brown at the margin, white at the middle toward the center; from below white to cream at the margin, brown to dark brown at the center, slightly radiated outward colonies; not producing pigmentation on PDA.

Material examined: CHINA, Yunnan Province, Yunnan Agricultural University , on a submerged decaying wood in a freshwater pond, 7 January 2022, Y.L. Yang, CFY-106 (HKAS 128978, holotype), ex-type living culture, KUNCC 10794 ; Kunming, Yunnan Agricultural University , on submerged decaying wood, 8 January 2022, Y.L. Yang, CFY-106–1 (HKAS 128979), living culture, KUNCC 10795 .

Notes: Phylogenetic analyses showed that Tetraploa lignicola forms a sister clade with T. endophytica (CBS 147114) and T. bambusae (KUNCC 21-0844) with 99%ML/1.00PP statistical support. However, T. endophytica is an endophytic fungus ( Crous et al. 2019), while T. lignicola is an exophytic fungus. Based on a nucleotide pairwise comparison, T. lignicola (HKAS 128978) differs from T. endophytica (CBS 147114) in 9/495 bp of ITS (1.8%) and 11/735 bp of LSU (1.5%), T. lignicola is defined as a new species ( Jeewon & Hyde 2016). Morphologically, T. lignicola is similar to T. bambusae in having conidia with four column cells, which are cylindrical, septate, brown or dark brown, verrucose, and septate with four appendages at the apex ( Phookamsak et al. 2022). However, T. lignicola differs from the latter in having larger conidia (38–53 × 22–39 vs 21–33 × 17–26 μm) and fewer conidial septa (3-septate vs 4- septate) ( Phookamsak et al. 2022). Moreover, the appendages of T. lignicola are longer than T. bambusae (98–127 × 5–7 vs 15–40 × 2.5–4.5 μm) and have more septa (5–10-septate vs. 1–3-septate) ( Phookamsak et al. 2022). Tetraploa lignicola differs from T. circinata in having larger conidia (38–53 × 22–39 vs 13–24 × 12–26 μm), fewer conidial septa (3-septate vs 1–4-septate) and shorter appendages (98–127 × 5–7 vs 54–415 × 2–4 μm) ( Pratibha & Bhat 2008).

Figures

FIGURE 2. Tetraploa lignicola (HKAS 128978, holotype). a Colonies on the substrate. b Conidia with separable columns. c–g Conidia. h Cultures on PDA. Scale bars: b–d, f, g = 20 μm, e = 50 μm.