Acanthohelicospora aurea (Corda) Rossman & W.C. Allen

Lu, Yong-Zhong, Boonmee, Saranyaphat, Bhat, D. Jayarama, Hyde, Kevin D. & Kang, Ji-Chuan, 2017, Helicosporium luteosporum sp. nov. and Acanthohelicospora aurea (Tubeufiaceae, Tubeufiales) from terrestrial habitats, Phytotaxa 319 (3), pp. 241-253 : 245-248

Acanthohelicospora aurea (Corda) Rossman & W.C. Allen , IMAfungus 7(1): 1–7 (2016) FIGURES 2–3

Index Fungorum number: IF 815416; Facesoffungi number: FoF 02762

Saprobic on decaying wood, in terrestrial habitat. Sexual morph: Ascomata 324–449 μm high × 267–408 μm diam. Superficial, solitary, scattered, globose to subglobose, black, apical ostiolate and shiny, surrounded by black setae; with setae tapering towards acute at the apex, 66–135 (–178) long × 5.5–7 μm wide. Peridium 30–40 μm wide, thickened, composed of several layers, with outer layer of compressed of widest textura angularis of brown cells, inner layer with compressed brown cells of textura angularis. Hamathecium comprising numerous, ca. 2 μm wide, cylindrical to filiform, septate, branched, hyaline pseudoparaphyses. Asci 121–162× 9.5–13 μm (x = 138 × 11 μm, n = 50), 8- spored, bitunicate, cylindrical, apically thickened and rounded, sessile to pedicellate.Ascospores 79–107 × 2.5–4 μm (x = 94 × 3.2 μm, n = 50), overlappingly fasciculate, long cylindrical-filiform, sometimes slightly fusiform, straight to slightly curved, 11–13-septate, not constricted at septum, hyaline, smooth-walled. Asexual morph: hyphomycetous, helicosporous. Colonies effuse, yellow green, loosely cotton-like, superficial on substratum. Mycelium with branched, septate, brown, smooth-walled, 2–5 μm diam. creeping hyphae. Conidiophores up to 700 μm long, 5.5–7.5 μm wide, macronematous, mononematous, simple, erect, stiff and bristle-like, widest at the base, tapering toward narrow apex, unbranched, septate, fuscous to dark brown, smooth-walled. Conidiogenous cells denticulate, holoblastic, monoblastic to polyblastic, hyaline, discrete, arising laterally from lower portion of the conidiophores as tiny bladder-like protrusions, 3–4.5 μm diam., with each bearing 1–4 tiny sporogenous conidiogenous loci. Conidia 27–49 μm diam., with conidial filament 2.5–3.5 μm wide, 142–199 μm long, pleurogenous, developing on tooth-like protrusion, loosely coiled 1½–2 times, getting uncoiled in water, multi-septate, hyaline, smooth-walled.

Culture characteristics:— Ascospores and conidia germinating on water agar (WA) within 24 h and many germ tubes produced from ascospore and conidium cells. Colonies growing on potato dextrose agar medium (PDA), form irregular , surface rough, umbonate, edge undulate, reaching 5 mm in two weeks at 28°C, brown. Mycelium superficial and partially immersed, branched, septate, hyaline to pale brown, smooth-walled.

Material examined:— CHINA, Guangxi Province, Hechi City, Mulun National Nature Reserve , on decaying wood in terrestrial habitat in the mountain, 19 May 2016, Yong-Zhong Lu, ML02 ( GZAAS 16–0071 ), living culture, GZCC 16–0059 ; ML02-2 ( GZAAS 16–0072 ), living culture, GZCC 16–0060 .

Notes:— Two new collections of Acanthohelicospora aurea ( GZAAS 16–0071 and GZAAS 16–0072) were found as sexual and asexual forms on decaying wood specimens. The sexual morph of Acanthohelicospora aurea ( GZAAS 16–0071) shares similar ascomata and asci characters to A. pinicola and A. scopula , but differs in having cylindricfiliform to fusiform and longer ascospores ( FIG. 2 , Boonmee et al. 2014). Phylogenetic analysis placed the sexual and asexual morphs specimens together with A. aurea ( NBRC 7098) with highly-supported ( FIG. 1 ). Therefore, the sexual and asexual morphs of Acanthohelicospora aurea are presented in this study.

Figures

FIGURE 1. Phylogenetic tree based on analysis of a combined ITS, LSU and TEF1α dataset. Bootstrap support values for RAxML and maximum parsimony (MP) greater than 75% and Bayesian posterior probabilities greater than 0.95 (PP) are indicated above or below the nodes as MLBS/MPBS/PP. The tree is rooted with Botryosphaeria dothidea CBS 115476 (Botryosphaeriaceae). The type species of each genus are in bold and new isolates are in bold and red.

FIGURE 2. Acanthohelicospora aurea (GZAAS 16–0071).a Superficial ascoma on wood substrate.b Cross section of ascoma.c Peridium. d seta. e Asci with hamathecium. f–g Hamathecium pseudoparaphyses. h–k Ascus. l–o Ascospore. p Germinating ascospore. q–r Colonies on PDA from above and below. Scale bars: b = 100 μm, c = 10 μm, d, f–g, q–r = 20 μm, e, h–p = 50 μm, q–r = 20 mm.

FIGURE 3. Acanthohelicospora aurea (GZAAS 16–0072).a–b Colony on wood substrate.c–d Conidiophores and conidia. e The bladderlike conidiogenous cells with denticulate conidiogenous loci. f–h Conidiogenous cells. i–l Conidium. m Germinating conidium. n–o Colonies on PDA from above and below. Scale bars: c = 200 μm, d = 50 μm, e, i–m = 20 μm, f–h = 5 μm, n–o = 20 mm.