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

Fig. 3

Etymology.

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

Holotype.

GMB-W1283.

Description.

Saprobic on dead culms of bamboo. Sexual morph: Ascomata 540-700 × 320-450 µm (x- = 586 × 389 µm, n = 20), immersed beneath a black clypeus, forming white ring surrounding ostioles of ascomata, solitary or scattered, sometimes gregarious, globose to subglobose, dark brown to black. Ostioles papillate, central, black. Peridium 15-25 µm thick, comprised of several layers, thick-walled, dense, brown to hyaline, cells of textura angularis. Paraphyses 2.5-6 μm wide, hyaline, numerous, cylindrical, unbranched, septate. Asci 180-270 × 12-14 μm (x- = 213 × 12.8 μm, n = 20), 8-spored, unitunicate, cylindrical, pedicellate, straight or slightly curved, apically rounded, with a 3.7-4.7 μm wide, 2.5-3 μm high (x- = 4.3 × 2.7 μm, n = 20), wedge-shaped, J+, apical ring. Ascospores 23-27 × 8.5-9.5 μm (x- = 24.5 × 8.8 μm, n = 20), overlapping, uniseriate, initially hyaline, pale brown to dark brown when mature, ellipsoidal, medianly 1-septate, tapering towards both ends, slightly constricted at the septum, with longitudinal striation along entire length of the ascospore, surrounded by a 3.5-5 µm thick, distinct, globose to subglobose, mucilaginous sheath. Asexual morph: Undetermined.

Materials examined.

China, Yunnan Province, Xishuangbanna, Jinghong, Manzhang , Mengla , 21°91′97"N, 101°20′42"E, 617.14 m, on dead culms of bamboo, 16 August 2020, Dong-Qin Dai, Li-Su Han, DDQ00993, (GMB-W 1283 holotype), ibid. (ZHKU 23-0258, isotype), ibid. DDQ00993-1 (ZHKU 23-0280) .

Notes.

In the phylogenetic tree, our new collections of Arecophila xishuangbannaensis (GMB-W1283, ZHKU 23-0280) formed a well-separated sister branch with A. bambusae (HKUCC 4794) and Arecophila sp. (HKUCC 6487) with 92% ML, 0.94 PP statistical supports (Fig. 1 ). Based on a nucleotide base pair comparison, A. xishuangbannaensis differs from A. bambusae (HKUCC 4794) in LSU gene (15/736 bp, 2%). Morphologically, A. xishuangbannaensis is similar to A. bambusae , in having cylindrical asci and ellispoidal ascospores. However, our new taxon differs A. bambusae by forming a white ring surrounding ostioles of ascomata and having larger asci (180-270 × 12-14 μm vs. 132.5-140 × 7.5-8 µm) and larger ascospores (23-27 × 8.5-9.5 μm vs. 19-22.5 × 5.5-7 µm) ( Umali et al. 1999; Li et al. 2022). Arecophila xishuangbannaensis also resembles A. notabilis K.D. Hyde, but it has larger ascomata (586 × 389 µm vs. 400 × 360 µm) ( Hyde 1996). The spores of this species did not germinate on PDA or malt extract agar (MEA) media, thus no culture is available.

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 3. Arecophila xishuangbannaensis (GMB-W 1283, holotype) a bamboo specimen b, c appearance of ostioles on host surface d-f vertical sections of ascomata g peridium h paraphyses i-m asci n asci with J +, wedge-shaped rings (Stained in Melzer's reagent) o-t ascospores (s showing ascospore with longitudinal striations t ascospore stained in Indian ink showing mucilaginous sheath). Scale bars: 300 μm (d-f); 20 μm (g); 30 μm (h); 50 μm (i-m); 15 μm (n-t).