Collodiscula japonica I. Hino & Katum., Bull. Faculty Agricult.

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 : 273

Collodiscula japonica I. Hino & Katum., Bull. Faculty Agricult. , Yamaguchi University 6: 55 (1955) ( Fig. 3 )

≡ Acanthodochium collodisculae Samuels, J.D. Rogers & Nagas., Mycotaxon 28(2): 457 (1987)

MycoBank: MB295371

Saprobic on dead bamboo culms, arising from the center of the base and perpendicular to the surface of the substrate. Sexual morph: Stromata scattered, superficial, pulvinate, 0.8–1 mm diam., 0.3–0.6 mm high, containing 1(–3) ascomata, coronate with the outer stroma remaining as a ‘crown’ around the inner stroma, black, carbonaceous, the combined outer and inner stromal layers fused to form a single layer, easily stripped from the inner stroma. Perithecia semiglobose, 0.4–0.6 mm diam., 0.3–0.6 mm high. Asci 120–148 × 7.0–11.4 μm (mean 132 × 8.3 μm, n = 30), 8-spored, unitunicate, short-stipitate, apically rounded with a J+, funnel-shaped apical apparatus, blue staining in Melzer’s reagent. Ascospores 19–26 × 4.5–5.5 μm (mean 22.5 × 4.8 μm, n = 30), fusiform to narrowly fusiform, brown to dark brown, 1-septate, not or slightly constricted at septum, inaequilateral, with rounded ends, smooth- walled, lacking germ slits or appendages. Asexual morph: Acanthodochium collodisculae .

Specimens examined: — CHINA. Guizhou Province: Tongren City, Fanjingshan Nature Reserve (27.533842°N, 108.454326°E), elev. 920 m, on dead bamboo culms, 10 October 2020, Q.R. Li 2020 FJS37 (GMB0035, KUN-HKAS 112692; living culture, GMBC0035) .

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 and OA media.

Habitat/Distribution:— Known to inhabit dead bamboo, China, Japan, Russia.

Other specimens examined:— CHINA. Guizhou Province: Tongren City, Fanjingshan Nature Reserve (27.544283°N, 108.42908°E), elev. 1037 m, on dead bamboo culms, 10 October 2020, Q.R. Li, collection number: 2020 FJS29 (GMB0034, KUN-HKAS 112690; living culture, GMBC0034) .

Notes:— The genus Collodiscula was introduced and typified by C. japonica from bamboo culms in Japan. Subsequently, C. japonica has been reported from Russia ( Vasilyeva 1998), Taiwan ( Ju & Rogers 1999), and Zhejiang province, China ( Jaklitsch & Voglmayr 2012). Phylogenetic analyses of the combined ITS, RPB 2, β-tubulin and α-actin sequences dataset shows that our strains, GMB0034 and GMB0035, clade with C. japonica (CBS124266) with high support (95% ML, 0.98 BYPP; Fig. 1 ). The new collections are morphologically the same as C. japonica . Interestingly, all collections of C. japonica were found on the surface of bamboo culms.

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 3. Collodiscula japonica (GMB0035). A–C. Stromata on the surface of host. D. Transverse section of stroma. E. Longitudinal section of stroma. F, G.Ascus apex with a J+, apical apparatus (stained in Melzer’s reagent). H–J.Asci with ascospores. K–O.Ascospores. Scale bars: B–E = 200 μm, F–O = 10 μm.