Astrocystis bambusicola R.H. Perera & K.D. Hyde, in Hyde et al., Fungal Diversity 87: 173 (2017).
Index Fungorum: IF 553799; MycoBank number: MB 553799; Facesoffungi number: FoF 10187; Fig. 1
Saprobic on dead culms of Microstegium sp. appearing as black raised spots on the host. Sexual morph: Ascomata up to 173 μm in width and 135 μm in high, subglobose, black, perithecial, gregarious, superficial, 1–2-loculate, with flattened top and projecting papillas. Peridium 43–60 (x̄=50, n=10) μm, composed of membranous inner wall and black, fragile, carbonaceous outer wall. Paraphyses 3.8–8.3 (x̄=6.2, n=25) μm, septate, cylindrical, hyaline, unbranched, guttulate. Asci 84–121×6.8–11 (x̄=99×8.8, n = 30) μm, 8-spored, unitunicate, cylindrical, with a short pedicel and J + apical ring. Ascospores12–15×5.7–8 (x̄=14×6.5, n=50) μm, reniform, dark brown to black, uniseriate, aseptate, guttulate, smooth-walled, with a germ-slit, without a gelatinous sheath. Asexual morph: Not observed.
Culture characteristics – Culture was made from germinal ascospores that germinated on PDA within 24 h, at 23–25 °C. Colonies rapidly growing on PDA, reaching 30 mm at 8 days, white from above and reverse, cottony, circular, umbonate, edge irregular.
Material examined – China, Guizhou Province, Qianxinan Buyei and Miao Autonomous Prefecture, Ceheng County, Gaofeng Village, on dead culms of Microstegium sp. (Poaceae), 8 August 2018, D. P. Wei, GFC612 (KUNHKAS 125898), living culture KUNCC 22-12539.
Known hosts and distribution – Bamboo (Yunnan, China; Thailand) (Hyde et al. 2017, 2020a, b, c).
Genbank numbers – OQ029540 (ITS), OQ029613 (LSU), OQ061263 (SSU), OQ186444 (tef1), OQ186446 (tub2).
Notes – Astrocystis bambusicola has been reported on bamboo column from China and Thailand (Hyde et al. 2017, 2020a, b, c). Our isolate phylogenentically groups with Astrocystis bambusicola with great support (100% ML/1.00 BYPP, Fig. 2). Morphologically our isolate bears resemblance with Astrocystis bambusicola in the subglobose, black, superficial ascomata, carbonaceous peridium, cylindrical asci with J + apical ring and reniform, dark brown to black ascospores with a germ-slit. We introduce our isolate as a new host record species of Astrocystis bambusicola from Microstegium sp. in Guizhou Province, China.
Figure 1 – Astrocystis bambusicola (KUN-HKAS 125897, new record) a Substrate. b, c. Ascomata. d Section through ascoma. e–h Asci. i Paraphysis. j Asci with J.+ apical ring. k Ascospore. l, m Upper and reverse view of cultures on PDA at 8 days incubation. n Germinating spore. Scale bars: d, e = 50 μm, f–j = 30 μm, k, n = 10 μm. (j stained in Melzer’s reagent)
Figure 2 – RAxML tree inferred from combined ITS, LSU, rpb2 and tub2 sequence. Bootstrap support for maximum likelihood analysis≥50% and Bayesian posterior probabilities≥0.95 are denoted next to the notes in this order. The new collection is marked in blue bold font