Collodiscula lancangjiangensis Y.P. Wu & Q.R. Li, 2021

Wu, You-Peng, Pi, Yin-Hui, Long, Si-Han, Lin, Yan, Long, Qing-De, Kang, Ji-Chuan, Kang, Ying-Qian, Shen, Xiang-Chun, Wijayawardene, Nalin N., Zhang, Xu & Li, Qi-Rui, 2021, Morphological and phylogenetic study of five species of Astrocystis and Collodiscula on bamboo, Phytotaxa 522 (4), pp. 265-284 : 268-273

Collodiscula lancangjiangensis Y.P. Wu & Q.R. Li , sp. nov. ( Fig. 2 )

MycoBank: MB839642

Type:— CHINA. Yunnan Province: Baoshan City, Lancang River Nature Reserve (28.72997°N, 99.361083°E), elev. 2674 m, on dead bamboo culms, 10 October 2019, Yinhui Pi 2019LC157 (GMB0030, holotype; KUN-HKAS 112663, isotype; ex-type living culture, GMBC0030) .

Saprobic on dead bamboo culms. Sexual morph: Stromata scattered or gregarious, solitary, superficial, black, hexagonal prism, 0.5–0.8 mm diam., 0.3–0.6 mm high, containing 1–2 ascomata, with a circle of black tissue at the bottom, with a papillary ostiole. External stromatal layer black, carbonaceous, easily chipped away to reveal the thin, black ascomata. Ostioles papillate in the centre, black. Perithecia subglobose to globose, 0.4–0.8 mm diam., 0.3–0.6 mm high. Asci 145–175 × 9–16 μm (mean 162 × 11.8 μm, n = 30), 8-spored, unitunicate, short-pedicellate, apically rounded with a J+, wedge-shaped apical apparatus, blue staining in Melzer’s reagent, 3.0–3.5 μm (mean 3.2 μm, n = 30) high, 1.5–2.0 μm (mean 1.7 μm, n = 30) broad. Ascospores 26–36.5 × 5–7.5 μm (mean 31 × 6.5 μm, n = 30), overlapping uniseriate, fusiform, equilateral, 3-septate, not constricted at septa, yellowish brown, blunt at both ends, smooth-walled, lacking germ slits or appendages. Asexual morph: undetermined.

Culture characteristics:— Ascospores germinated on PDA within 24 hours at 25 °C, colonies, dense but thinning towards the edge, edge irregular, white from above, reverse similar in colour. No conidia were observed on PDA or oat agar (OA) media.

Habitat/Distribution:— Known to inhabit dead bamboo, Yunnan Province, China.

Etymology:— Refers to the location where the specimens were collected, Lancang River Nature Reserve.

Other material examined:— CHINA. Yunnan Province: Baoshan City, Lancang River Nature Reserve (25.7880°N, 99.352864°E), elev. 2656 m, on dead bamboo culms, 10 October 2019, Yinhui Pi 2019LC352 (GMB0031, KUN-HKAS 112678; no culture was obtained; DNA was extracted directly from asci and ascospores) ; Yunnan Province: Baoshan City, Lancang River Nature Reserve (25.033204°N, 99.361543°E), elev. 2676 m, on dead bamboo culms, 10 October 2019, Yinhui Pi 2019LC205 (GMB0038; KUN-HKAS 112669; no culture was obtained) .

Notes:— To date, six species of Collodiscula have been reported ( Hino & Katumoto 1955, Li et al. 2015a, b, Hyde et al. 2017, Xie et al. 2020). Collodiscula lancangjiangensis has 3-septate ascospores as does C. fangjingshanensis and C. leigongshanensis , which were collected from China. However, C. lancangjiangensis has larger ascospores than C. fangjingshanensis (19–25.5 × 4.5–6 μm) and C. leigongshanensis (28–35 × 8–10.5 μm). Phylogenetic analyses ( Fig. 1 ) indicates that C. lancangjiangensis is closely related to C. japonica with high bootstrap support and PP values (92% ML, 0.99 BYPP; Fig. 1 ), but forms a distinct lineage.

Figures

FIGURE 1. RAxML tree based on analysis of a combined dataset of ITS- RPB2-β-tubulin-α-actin sequence dataset from selected species of Xylariales. Bootstrap support values for maximum likelihood (ML) greater than 75%, and Bayesian posterior probabilities (BYPP) greater than 0.90 are given at the nodes. Strain numbers are noted after the species names. The tree is rooted to the outgroup of Daldinia loculatoides (CBS 113279), D. macaronesica (CBS 113040) and Hypoxylon rickii (MUCL 53309).

FIGURE 2. Collodiscula lancangjiangensis (GMB0030, holotype).A–C.Stromataon the surface of host.D.Transverse section of stroma. E. Longitudinal section of stroma. F.Ascus apex with a J+, apical apparatus (stained in Melzer’s reagent). G–I.Asci with ascospores. J–M. Ascospores. Scale bars: B–E = 200 μm, F–M = 10 μm.