B. Devadatha, V.V. Sarma. & E.B.G. Jones, Botanica Marina (2019)
Morosphaeriaceae, Subclass Pleosporomycetidae
Morosphaeria velataspora (K.D. Hyde & Borse) S. Suetrong, J. Sakayaroj, E.B.G. Jones & C.L. Schoch, Stud Mycol 64:161 (2009).
Morosphaeria muthupetensis B. Devadatha, V.V. Sarma & E.B.G. Jones, Bot Mar 61(4): 401 (2018).
MycoBank: MB823337 Facesoﬀungi: N/A
Saprobic marine ascomycete. Sexual morph: Ascomata 110–350 × 210–910 μm, immersed to erumpent, raised, sub-globose to lenticular, solitary to gregarious, coriaceous, brown, ostiolate. Ostiole 45–100 × 50–70 μm. Peridium unequal in thickness, composed of a thin layer of brown pseudoparenchymatous tissue with irregular cells fused with the host tissue, 15–25 μm, less developed at the base and 22–40 μm, at sides, comprising two strata, inner stratum with 2–3 layers of hyaline to light brown cells of textura angularis and outer stratum with compact light brown pseudoparenchymatous cells fused with the host tissue. Hamathecium is composed of 1–4 μm wide, numerous, septate, branched, filamentous to trabeculate pseudoparaphyses, resembling hyphae, embedded in a gelatinous matrix, anastomosing above the asci. Asci 115–240 × 15–20 μm, 8-spored, bitunicate, fissitunicate, cylindrical to clavate, short pedicellate, apically rounded and thickened with an ocular chamber. Ascospores 25–35 × 5–12.5 μm, overlapping uniseriate or biseriate, smoothwalled, hyaline, 1-septate, constricted at the septum, fusiform to ellipsoidal with acute ends, guttulate, each cell containing one large guttule and several oil globules, apical cell slightly larger than the lower cell, surrounded by a thick distinct mucilaginous sheath 2–4 μm. Asexual morph: unknown.
The description was based on Devadatha et al. (2018).
Key to species in the genus:
1a. Ascospores longer than 45 μm, 1–3 septate M. velatispora
1b. Ascospores shorter than 45μm, 1 septate 2
2a. Ascospores longer than 35 μm with a gelatinous
sheath extended to polar caps M. ramunculicola
2b. Ascospores shorter than 35 μm, with larger
guttules lacking polar caps M. muthupetensis
Devadatha B, Sarma VV, Jeewon R, Jones EBG (2018). Morosphaeria muthupetensis sp. nov. (Morosphaeriaceae) from India: morphological characterization and multigene phylogenetic inference. Bot Mar 61(4): 395-405.
Suetrong S, Schoch CL, Spatafora JW, Kohlmeyer J, Volkmann-Kohlmeyer B, Sakayaroj J, Phongpaichit S, Tanaka K, Hirayama K, Jones EBG (2009). Molecular systematics of the marine Dothideomycetes. Stud Mycol 64:155-173.
Morosphaeria muthupetensis (holotype). (A) Erumpent ascomata on decaying wood of Rhizophora mucronata. (B and C) Longitudinal sections of ascomata. (D) Peridial wall layers. (E) Hamathecium showing filamentous pseudoparaphyses. (F–J) Immature and mature asci. (K and L) Ascospores with guttules. (L–N) Ascospores with a distinct mucilaginous sheath. (O) Ascospore stained in Indian ink. (P) Germ tubes developed from terminal ends of ascospore. Arrows in (L–N) indicate the mucilaginous sheath. Scale bars: (A) = 250 μm, (B and C) = 100 μm, (F, H–J) = 50 μm, (D–E, G, K–P) = 10 μm.
The figure was taken from Devadatha et al. (2018).