Astrocystis bambusicola R.H. Perera & K.D. Hyde, Fungal Diversity

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 : 276-280

Astrocystis bambusicola R.H. Perera & K.D. Hyde, Fungal Diversity 87: 173 (2017) ( Fig. 5 )

MycoBank: MB552219

Saprobic on the surface of dead bamboo stalk, visible as black raised spots on the host. Sexual morph: Stromata erumpent, scattered, superficial, subglobose to dome-shaped, blackened, carbonaceous, with papillate ostioles, containing 1–3 ascomata, 0.20–0.73 mm diam., 0.13–0.20 mm high. Perithecia comprising black, fragile, carbonaceous tissue. Asci 119–132 × 8–11.5 μm (mean 124 × 9.6 μm, n = 30), 8-spored, unitunicate, cylindrical, with a short pedicel, persistent, apically rounded, with J+, square-shaped apical apparatus, blue staining in Melzer’s reagent, 3–4.5 μm (mean 3.2 μm, n = 30) high, 2.0–3.5 μm (mean 2.8 μm, n = 30) wide. Ascospores 18.0–26 × 6.5–11 μm (mean 20.8 × 8.0 μm, n = 30), uniseriate, ellipsoid, aseptate, brown to dark brown, guttulate, smooth-walled, with a germ slit slightly less than full spore-length, lacking appendages and sheath. Asexual morph: undetermined.

Specimens examined:— CHINA. Guizhou Province: Tongren City, Fanjingshan Nature Reserve (27.544623°N, 108.454326°E), elev. 912 m, on dead bamboo culms, 10 October 2020, Q.R. Li 2020FJS35 (GMB0036, KUN-HKAS 112691; living culture, GMBC0036) .

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 OA media.

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

Notes:— Morphologically, A. bambusicola differs from A. mirabilis and A. bambusae by its superficial stromata, larger ascospores and smaller asci. Phylogenetic analyses of a combined ITS, RPB2, β-tubulin and α-actin sequences dataset shows that our strain GMB0036 clades with the type strain of A. bambusicola (MFLUCC 17-0127) with high statistical support (99% ML, 0.99 BYPP; Fig. 1 ). The new collection morphologically resembles A. bambusicola . Thus, we identify it as A. bambusicola which has been reported in Thailand ( Hyde et al. 2017) and Yunnan, China ( Hyde et al. 2019).

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 5. Astrocystis bambusicola (GMB0036).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–K.Asci with ascospores. L–O.Ascospores. Scale bars: B–E = 200 μm, F–O = 10 μm.