Roussoella pustulans (Ellis & Everh.) Y.M. Ju, J.D. Rogers & Huhndorf, Mycotaxon

Liu, Jian-Kui, Phookamsak, Rungtiwa, Dai, Dong-Qin, Tanaka, Kazuaki, Jones, Gareth, Xu, Jian-Chu, Chukeatirote, Ekachai & Hyde, Kevin D., 2014, Roussoellaceae, a new pleosporalean family to accommodate the genera Neoroussoella gen. nov., Roussoella and Roussoellopsis, Phytotaxa 181 (1), pp. 1-33 : 15-16

Roussoella pustulans (Ellis & Everh.) Y.M. Ju, J.D. Rogers & Huhndorf, Mycotaxon 58: 448. 1996. FIG. 9

≡ Diatrype pustulans Ellis & Everh., J. Mycol. 4(8): 80. 1888.

Saprobic on decaying bamboo culms or palms branches. Ascostromata 1 mm diam., immersed under a clypeus, raised, visible as black, dome-shape areas on host surface, uni-biloculate, scattered to grouped. Locules 150–170 µm high, 300–430 µm diam, depressed globose with a flattened base, single or grouped, ostiolate. Peridium 12–17 µm thick at sides, composed of polygonal to subglobose cells (3.5–15 × 3.5–5 µm), surrounded by wedge-shaped stromatic region composed of hyphal cells. Hamathecium comprising 1–2 µm wide, numerous, anastomosing, cellular pseudoparaphyses, branching at the apex, rough-walled, and embedded in a gelatinous matrix. Asci 68–83 × 6.5–8.5 µm, 8-spored, bitunicate, cylindrical, with a short stipe (15–18 µm long). Ascospores 10–16 × 4–5 µm (x = 12.5 × 4.5 µm, n = 50), fusiform to ellipsoidal, with a median septum, 2-celled, brown, covered with irregular longitudinal striations. Conidiomata produced in culture, 200–300 µm high, 300–1100 µm diam, subglobose, single to gregarious. Conidiophores absent. Conidiogenous cells 5–13 × 2–4 µm (x = 8.5 × 2.5 µm, n = 25), phialidic, ampulliform. Conidia 4–5 × 2–3 µm (x = 4.6 × 2.6 µm, n = 50), ellipsoidal, yellowish brown, smooth.

Specimen examined. JAPAN, Hokkaido, Sapporo , on twigs of Sasa kurilensis , 6 June 2004, K . Tanaka, KT 1709 (= HHUF 29229 , living culture JCM 13127 = MAFF 239637 ) .

Notes: This species is similar to R. pustulans described by Ju et al. (1996) and Hyde (1997), but the ascospores are slightly narrower. The asexual morph formed in culture differs from Cytoplea in having smooth-walled, conidia and is similar to the asexual morph of R. chiangraina . However, these taxa are phylogenetically distinct (FIGS. 1, 2).

Figures

FIGURE 9. Roussoella pustulans. a, b. Ascostromata on host surface; c. Section of ascostroma; d, e. Asci; f. Pseudoparaphyses; g–k. Ascospores; l. Section of conidioma (in lactophenol cotton blue); m. Conidia; a–k from KT 1709 (= HHUF 29229); l, m from culture JCM 13127 = MAFF 239637. ─ Scale bars: a, b = 1 mm, c = 500 µm; d, n = 100 µm; e–i = 20 µm; j–m, o = 5 µm.