Arecophila zhaotongensis L.S. Han & D.Q. Dai, 2024

Han, Li-Su, Wijayawardene, Nalin N., Liu, Chao, Han, Li-Hong, Promputtha, Itthayakorn, Li, Qiang, Elgorban, Abdallah M., Al-Rejaie, Salim, Tanaka, Kazuaki & Dai, Dong-Qin, 2024, Paramphibambusa bambusicola gen. et. sp. nov., Arecophila xishuangbannaensis and A. zhaotongensis spp. nov. in Cainiaceae from Yunnan, China, MycoKeys 104, pp. 113-132 : 113

Arecophila zhaotongensis L.S. Han & D.Q. Dai sp. nov.

Fig. 4

Etymology.

Named after the location “Zhaotong” where the new taxon was discovered.

Holotype.

GMB-W1353.

Description.

Saprobic on dead culms of bamboo. Sexual morph: Ascomata 600-960 × 450-550 µm (x- = 710 × 500 µm, n = 20), immersed beneath blackened clypeus, clypeus well-developed, darkened raised discs, or as tiny ostiolar dots, solitary, scattered, sometimes gregarious, dark brown to black, globose to subglobose, papillate, with a central ostiole. Peridium 15-25 µm thick, comprising several layers, thick-walled, brown cells of textura angularis. Paraphyses 1-3 µm wide, hyaline, numerous, filiform, branched. Asci 190-240 × 10.5-14 µm (x- = 215 × 11.6 µm, n = 20), 4- or 8-spored, rarely 6-spored, cylindrical, unitunicate, short pedicellate, straight or slightly curved, rounded at the apex, with a 4-4.5 μm wide, 2-2.5 µm high (x- = 4.2 × 2.2 µm, n = 20), trapezoidal, J+, apical ring. Ascospores 21-30 × 6-8 µm (x- = 25.5 × 7 µm, n = 20), uniseriate or overlapping uniseriate, brown, ellipsoidal, 1-septate, septate at the centre, slightly tapering at the ends, with longitudinal and sulcate striations, surrounded by a 5-10.5 µm wide, distinct, oval to spherical, mucilaginous sheath. Asexual morph: Undetermined.

Culture characters.

Ascospores germinating within 24 h. Colonies reach 20 mm diam. in 15 days under dark and at 28 °C conditions, circular, hairy, white from above, and yellow to yellowish from below.

Materials examined.

China, Yunnan Province, Diqin, Shangri-La, Bigu Mountain , on dead culms of bamboo, 22 July 2020, 27°36′56.9"N, 99°42′6.4"E, 3460 m, Dong-Qin Dai DDQ00740 (ZHKU 23-0261); Zhaotong, Zhenxiong S 302, 27°36′8"N, 104°56′34"E, 1673.07 m, on dead culms of bamboo, 29 July 2021, Dong-Qin Dai, Li-Su Han, DDQ02079, (GMB-W1353, holotype), GMBCC1145, ex-type; ibid. (ZHKU 23-0259, isotype), Z HKUCC 23-0975, ex-isotype; ibid. DDQ02105 (ZHKU 23-0260) .

Notes.

In the phylogenetic tree, the new species A. zhaotongensis (GMBCC 1145, ZHKU 23-0259, ZHKU 23-0260) formed a separated sister branch to A. bambusae (HKUCC 4794), Arecophila sp. (HKUCC 6487) and A. xishuangbannaensis (GMB-W1283, ZHKU 23-0280) with 89% ML, 0.99 PP statistical supports (Fig. 1 ). Based on a nucleotide pairwise comparison, A. zhaotongensis differs from A. bambusae (HKUCC 4794) in 26/736 bp of LSU (3.5%), and differs from A. xishuangbannaensis (GMB-W1283, ZHKU 22-0280) in 56/563 bp of ITS (9.9%), 18/736 bp of LSU (2.4%). Arecophila zhaotongensis has larger asci than A. bambusae (190-240 × 10.5-14 µm vs. 132.5-140 × 7.5-8 µm) and larger ascospores (21-30 × 6-8 µm vs. 19-22.5 × 5.5-7 µm) ( Umali et al. 1999). Arecophila zhaotongensis differs from A. xishuangbannaensis (GMB-W1283, ZHKU 23-0280) in having narrower ascospores (21-30 × 6-8 µm vs. 23-27 × 8.5-9.5 µm). The new species also resembles A. muroiana (I. Hino & Katum.) You Z. Wang et al. ( Wang et al. 2004). However, A. muroiana lacks a clypeus absent, while a blackened clypeus was observed in A. zhaotongensis .

Figures

Figure 1. The RAxML tree was generated based on the combined ITS, LSU, rpb 2, and tub sequence data. Bootstrap support values for ML equal to or greater than 60 %, and Bayesian posterior probabilities (BYPP) equal to or higher than 0.90 are indicated above the nodes as ML / PP. Type materials are indicated by superscript " T ", while the newly generated sequences are shown in red.

Figure 4. Arecophila zhaotongensis (GMB-W 1353, holotype) a bamboo specimen b, c appearance of ostioles at the host surface d, e vertical sections of ascomata with ostioles and black clypei f peridium g paraphyses h-m asci n, o asci with a J + trapezoidal ring (stained in Melzer's reagent) p-t ascospores surrounded by mucilaginous sheath (t ascospore with longitudinal striations) u a germinating ascospore v, w cultures on PDA after 15 days (v upper, w reverse). Scale bars: 300 µm (d, e); 30 µm (f, g); 50 µm (h-m); 15 µm (n-u).