Tetraploa cylindrica C.F. Liao & Doilom, 2022

Liao, Chun-Fang, Dong, Wei, Thilini Chethana, K. W., Pem, Dhandevi, Phookamsak, Rungtiwa, Suwannarach, Nakarin & Doilom, Mingkwan, 2022, Morphological and phylogenetic evidence reveal Tetraploa cylindrica sp. nov. (Tetraplosphaeriaceae, Pleosporales) from Saccharum arundinaceum (Poaceae) in Yunnan Province, China, Phytotaxa 554 (2), pp. 189-200 : 195-196

Tetraploa cylindrica C.F. Liao & Doilom , sp. nov. ( FIGURE 3 )

Index Fungorum number: IF558012; Facesoffungi number: FoF 09425

Etymology:—In reference to cylindrical conidia of the fungus to be same as below line (Holotype)

Holotype:— KUN-HKAS 1047393

Saprobic on decaying stems of Saccharum arundinaceum . Sexual morph: undetermined. Asexual morph: hyphomycetous. Colonies effuse, dark brown to black, gregarious on host substrate. Mycelium semi-immersed or immersed, branched, septate. Conidiophores absent. Conidiogenous cells integrated, determinate. Conidia 18–42 × 15–27 µm (x = 30 × 22 µm, n = 40), cylindrical with obtuse ends, dark brown to black, composed of four columns of cells, 4-septate in each column, coarsely verruculose, mostly with three apical appendages, some with one, two or four appendages. Appendages 40–210 µm long, 3–6 µm wide at the base, gradually tapering to the tip, 1–2 µm wide at the apex, divergent, pale brown to brown, 6–13-septate, straight or slightly flexuous, smooth-walled.

Culture characteristics:—Conidia germinated on PDA at room temperature (25±2 ˚C) within 12 hours, germination tube grow from both ends. Colonies reaching 13 to 16 mm in diam. after four weeks at 28 ˚C, mostly immersed in culture, irregular, dense, raised in the middle. Front grey brown in the middle, dark brown to black towards the margin, umbonate, flossy, velvety; Reverse black with brown margin. No pigments production.

Material examined:— China, Yunnan Province, Kunming city, from decaying stems of Saccharum arundinaceum Retz. (Poaceae) , 19 July 2019, C.F. Liao, (KUN-HKAS 1047393, holotype), ex-type living culture KUMCC 20-0205 = ZHKU 22-0054; ex-paratype living culture ZHKUCC 22-0087.

Notes:— Tetraploa cylindrica forms a well-supported subclade with T. aquatica , T. dashaoensis and T. nagasakiensis in our multi-locus phylogenetic analysis ( FIGURE 2 ). They share similar morphological characteristics in having cylindrical conidia with four columns of cells and four apical appendages, as well as the overlapping conidial body size. However, T. cylindrica differs from T. aquatica in having divergent and longer appendages (40–210 µm long). In contrast, T. aquatica has closely adhered and shorter appendages (98–134 μm long, Li et al. 2020). Tetraploa dashaoensis has divergent appendages, but they are slightly longer than T. cylindrica (148–258 μm long vs. 40–210 µm long) (pers. comm. Jayawardena R.S.). Tetraploa nagasakiensis has a divergent and similar length of appendages with T. cylindrica , but T. nagasakiensis has brown conidia compared to the dark brown to black conidia of the latter ( Tanaka et al. 2009). Tetraploa cylindrica resembles T. aristata in having cylindrical conidia with four columns of cells and four apical appendages, but differs in having longer appendages (40–210 µm long vs. 12–80 µm long) ( Ellis 1949). A synoposis of Tetraploa cylindrica and similar species is also provided in TABLE 2 . Based on both morphological and multi-locus phylogeny the taxon isolated in this study is established as a new species.

Figures

FIGURE 2. RAxML tree is generated from combined LSU, SSU, ITS, β-tubulin and tef1-α sequence data.Bootstrap support values for ML and MP equal to or greater than 75% and BI equal to or greater than 0.95 are given near the branches. The tree is rooted in Muritestudina chiangraiensis (MFLUCC 17-2551). The ex-type cultures are indicated using “T” after strain codes and the newly introduced taxa are indicated in blue.

FIGURE 3. Tetraploa cylindrica (KUN-HKAS 1047393, holotype). a–c Colonies on natural substrates. d–g Conidia bearing 1–4 appendages. h Conidial body showing verrucose ornamentation. i Germinating conidium. j Colony on PDA (left-front, right-reverse). Scale bars: d–g, i = 100 μm, h = 10 μm.