Rhexoacrodictys erecta (Ellis & Everh.) W.A. Baker & Morgan-Jones, in Baker, Partridge & Morgan-Jones, Mycotaxon 82: 99 (2002)
Index Fungorum number: IF 381123; MycoBank number: MB 381123; Facesoffungi number: FoF 13392; Fig. 1
Saprobic on dead culms of bamboo. Sexual morph: Not observed. Asexual morph: Colonies on the substratum superficial, hairy, effuse, blackish, shining. Mycelium mostly immersed, cylindrical, brown to dark brown hyphae. Conidiophores 28–57 × 4–5 μm ( x̄ = 42.5 × 4.5 μm, n = 15), macronematous, mononematous, erect, single, straight or somewhat flexuous, cylindrical, smooth-walled, brown to dark brown, septate. Conidiogenous cells monoblastic, pale brown to brown, integrated, terminal. Conidia 19–27.5×15–19 μm (x̄ =23.5×17 μm, n=30), holoblastic, solitary, dry, broad oval to subglobose, muriform, acrogenous, transversely and longitudinally septate, dark brown to black, smoothwalled, narrowly truncate at the base.
Culture characteristics – Colonies on PDA, 30 mm diam after two weeks at 28 °C, brown to blackish at the front and reverse sides, mycelium sparse; reverse blackish.
Material examined – Thailand, Chiang Rai Province, Muang District, on dead culms of Bambusa sp. (Poaceae), 11 November 2020, X. G. Tian U–2–3 (MFLU 21–0277), living culture, MFLUCC 21–0157.
Habitat – on submerged wood, Arundo donax, Bambusa multiplex, Bambusa sp., Fagus crenata, palm tree, Saccharum officinarum, Sorghum bicolor, Sporoschisma saccardoi and Zea mays (Ellis 1961; Baker et al. 2002; Zhao et al. 2011; Xia et al. 2017; Shi et al. 2021).
Distribution – Known from China, India, Japan, Sierra Leone, South Africa, Thailand, USA and Venezuela (Ellis 1961; Baker et al. 2002; Zhao et al. 2011; Xia et al. 2017; Shi et al. 2021; This study).
GenBank numbers – OL606411 (ITS), OL606151 (LSU), OL606015 (SSU).
Notes – This species was reported as Acrodictys erecta on Arundo donax in Venezuela and on Zea mays in USA by Ellis (1961). Baker et al. (2002) examined several type specimens of synonyms of this species and erected Rhexoacrodictys based on morphological analysis. Our new isolate (MFLUCC 21-0157) clustered with the strains of Rhexoacrodictys erecta (HMAS 245615, IFRD500–016 and HMAS 245616; Fig. 2). Morphologically, our new collection is similar to those of Rhexoacrodictys erecta (Ellis 1961; Baker et al. 2002).
Figure 1 – Rhexoacrodictys erecta (MFLU 21–0277, new record). a, b Colonies on wood. c–f Conidiophore with conidia. g–i Conidia. j Germinating conidia. k, l Culture on PDA from surface and reverse. Scale bars: c–f, j=20 μm, g–i=10 μm
Figure 2 – Combined phylogeny using ITS, LSU SSU, rpb2 and tef1 of selected members of four orders of the Hypocreomycetidae. The dataset of combined ITS, LSU, SSU, rpb2 and tef1 sequence data comprise 79 strains with 4413 characters including gaps (rpb2: 1–1051 bp, tef1: 1052–2046 bp, ITS: 2047–2623 bp, LSU: 2624–3413 bp, SSU: 3414–4413 bp). Leotia lubrica (AFTOL-ID1) and Microglossum rufum (AFTOL-ID 1292) were used as outgroup taxa. RAxML and Bayesian analyses were conducted and resulted in generally congruent topologies. Bootstrap support values for ML ≥75% and BYPP ≥0.95 are given as ML/BYPPP above the nodes. Newly obtained sequences are indicated in red and ex-type strains are in bold