Pseudorobillarda sojae Uecker & Kulik, Mycologia 78(3): 450 (1986)
Facesoffungi number: FoF 07566
Caulicolous to foliicolous. Sexual morph: undetermined. Asexual morph: Conidiomata 100–250 µm diam., 100–300 µm high, fuscous, pycnidial, scattered to gregarious, subepidermal, deeply immersed, appearing as dark brown to black specks beneath the epidermis in surface view, with a globose or depressed globose or irregular in shape venter, and an oval or subcylindrical neck, unilocular, glabrous, thick-walled, ostiolate. Ostiole 50–95 × 40–60 µm, circular to subcylindrical, single, centrally or laterally located. Conidiomatal wall 10–30 µm wide, composed of thick-walled, dark brown to brown cells of textura angularis in the outer layers, and thick-walled, hyaline cells of textura prismatica in the inner layers. Paraphyses absent. Conidiophores reduced to conidiogenous cells. Conidiogenous cells 4–7 × 3–5 µm, hyaline, enteroblastic, phialidic, short cylindrical to subcylindrical, determinate, with marked periclinal thickenings at collarette zone, arising from the inner wall layer of conidiomata. Conidia 13.5–19 × 3–5 µm ( = 16.5 × 4 µm; n = 50), hyaline, subcylindrical to fusiform, with a bluntly rounded apex, and a broadly truncate base, unicellular, guttulate, thick- and smooth-walled, bearing 3–4, flexuous, divergent, extracellular, apical appendages (10–21 µm long).
Material examined: Cuba, Pinar del Rio, on decaying leaves of unidentified angiosperm, 1 June 1988, T.R. Nag Raj (DAOM 215313).
Notes: Pseudorobillarda sojae was described from soybean stems on water agar in the USA (Uecker and Kulik 1986). Abbas et al. (2002) excluded P. sojae from Pseudorobillarda, because it lacks paraphyses and its conidia are aseptate, feature which are present in P. phragmitis. However, Plaingam et al. (2005) and Tangthirasunun et al. (2014) showed P. sojae was phylogenetically related to the type species and included the species in Pseudorobillarda. Three unnamed Pseudorobillarda species (MFLUCC 12-0423, MFLUCC 12-0422, MFLUCC 12-0316) clustered phylogenetically with P. sojae. and morphologically, P. sojae, and the three unnamed strains share similar form of conidiomata, conidiogenous cells and conidia dimensions with P. sojae. Therefore, these three strains are regarded as conspecific with P. sojae. A synopsis of all P. sojae strains is provided.
Pseudorobillarda sojae (DAOM 215313) a, b Herbarium package and specimen. c, d Appearance of dark brown to black specks beneath the epidermis. e Side view of conidioma. f, g Vertical sections of conidiomata. h, i Sections of peridium. j–l Conidiogenous cells and developing conidia. m–o Conidia. Scale bars c = 200 µm, d–f = 100 µm, g = 50 µm, h–i = 20 µm, j–o = 5 µm.
Li WJ, McKenZie EHC, Liu JK, Bhat DJ, Dai DQ, Caporesi E, Tian Q, Maharachcikumbura SSN, Luo ZL, Shang QJ, Zhang JF, Tangthirasunun N, Karunarathna SC, Xu JC, Hyde KD (2020) Taxonomy and phylogeny of hyaline-spored coelomycetes. Fungal Diversity 100: pages279–801.