Muriphaeosphaeria galatellae Phukhamsakda, Bulgakov & K.D. Hyde, 2015

Phukhamsakda, Chayanard, Ariyawansa, Hiran A., Phookamsak, Rungtiwa, Chomnunti, Putarak, Bulgakov, Timur S., Yang, Jun-Bo, Bhat, Darbhe J., Bahkali, Ali H. & Hyde, Kevin D., 2015, Muriphaeosphaeria galatellae gen. et sp. nov. in Phaeosphaeriaceae (Pleosporales), Phytotaxa 227 (1), pp. 55-65 : 60-62

Muriphaeosphaeria galatellae Phukhamsakda, Bulgakov & K.D. Hyde , sp. nov. FIG. 3

Index Fungorum Number IF551292; Facesoffungi number FoF 00643

Etymology: —Named after the host genus from which it was isolated, Galatella .

Holotype: MFLU 15−0087

Saprobic on dead and dying stems of Galatella villosa ( L.) Rchb.f. Sexual morph: Ascomata 114−180 μm high × 167–263 μm wide, oriaceous, superficial, flat at the base, globose to cupulate, black to dark brown, solitary, scattered, without a papilla, smooth-walled. Ostiole 16−22 μm high × 22−32 μm wide, slightly raised, centrally located, lacking periphyses. Peridium 12–26 μm wide, composed of 3–5 wall layers, with outer part comprising dark brown to light brown cells of textura angularis, inner layer comprising thin-walled, hyaline cells. Hamathecium of dense, 2–3 μm (x = 2.7 μm, n = 20) wide, filamentous, septate, branched, pseudoparaphyses surrounding asci. Asci 53–86 × 9–17 μm (x = 77.5 × 13.6 μm, n = 20), 8-spored, bitunicate, fissitunicate, cylindrical to clavate, short-pedicellate, apically rounded with an ocular chamber, clearly visible when immature. Ascospores 13–27 × 4–11 μm (x = 22.1 × 7.8 μm, n=50), bi-seriate, partially overlapping, obovoid to sub-fusiform, or clavate, narrow towards ends, slightly curved, 4–5-tranversely septate and with 1 longitudinal septa in the central 2–3 cells, constricted at three central septa, slightly constricted at other septa, with second cell from apex enlarged in the centre, light brown to yellowish, granulate, smooth-walled, without a mucilaginous sheath. Asexual morph: Produced on sterilized bamboo pieces and pine needles on water agar. Conidiomata 233−293 μm high × 202–332 μm wide diam., dark brown to black, globose, superficial on substrate, covered by dense vegetative hyphae, uniloculate, solitary to scattered, ostiolate. Pycnidial wall 41−54 μm wide (up to 85 μm wide at apex), thick-walled, two-layered, with outer region comprising 2-layers of brown-walled cells of textura angularis, with inner region comprising up to 7 layers of thick, hyaline cells of textura angularis. Conidiophores reduced to conidiogenous cells. Conidiogenous cells 1−3 × 2−3 μm, holoblastic with percurrent proliferations, annellidic, integrated, oblong, hyaline, and formed from the inner layer of pycnidium wall. Conidia 10–17 × 2–6 μm (x = 14.2 × 4.6 μm, n = 50), cylindrical to subclavate, rounded at both ends, sometimes slightly curved, with 1−3 transverse septa, initially hyaline, brown when mature, smooth-walled.

Culture characters: —Ascospore germinating on PDA within 24 hours, with germ tubes developed from the end cells of ascospores. Colonies on PDA reaching 60 mm diam after 4 weeks. Culture incubated at 16 ° C, white at first, becoming pale green after 2 weeks, olive-green, convex with papillate surface, with circular, friable margin.

Material examined: — RUSSIA, Rostov region (rus. Rostovskaya Oblast), Oktyabrsky District (rus. Oktyabr’sky raion), natural sanctuary ‘Persianovskaya steppe’, dead and drying stems of Galatella villosa ( L.) Rchb.f. ( Asteraceae ) ( FIG. 2A ), 26 April 2014, T. S. Bulgakov ( MFLU, holotype 15−0087; HKAS 88183, isotype); ex-type living culture, MFLUCC 14–0614 = MFLUCC 15−0769 = CBS 140021.

Notes: —The genus Muriphaeosphaeria is a monotypic and characterized by superficial, globose to cupulate, ostiolate ascomata, thick-walled peridium, filamentous, septate, pseudoparaphyses, bitunicate, fissitunicate, short and narrowly pedicellate asci and muriform ascospores.The asexual morph of the genus ( MFLUCC 15−0769, FIG. 2C ) found in same pieces of host and also formed in culture ( MFLUCC 14−0614, FIG. 2B , FIG. 3 ) is coelomycetous with pycnidial, globose, superficial, uniloculate, ostiolate, thick-walled conidiomata, with an inner wall-layer comprising up to 7 hyaline cell-layers, annelledic conidiogenous cells, and subclavate, 1−3-transverse septate, brown conidia. The connectively of sexual and as asexual morphs is proven by phylogenetic analysis ( FIG. 1 ). Muriphaeosphaeria galatellae forms a sister clade with a putative strain of Entodesmium rude ( CBS 650.86, FIG. 1 ), but the morphology is obviously distinct. E. rude has long necked, periphysate ostiole, thick-walled peridium, fasciculate, scolecosporous, filiform, 18−20-septate ascospores ( Phookamsak et al. 2014b). Muriphaeosphaeria galatellae shares similarities with Dematiopleospora mariae ( Wanasinghe et al. 2014) in having superficial ascomata and muriform ascospores, but differs in having thick-walled ascomata, without loose hyphae surrounding the ostiole, filamentous, cellular pseudoparaphyses, short and simple pedicellate asci and ascospores with rounded ends, while D. mariae contains hyphae around the ostiole and furcated pedicellate asci. Both taxa cluster in the clade A, with in the family in molecular analysis ( FIG. 1 ). Thus, it is evident that more taxa are needed to be studied to resolve the relationship within the clade.

Figures

FIGURE 1. Bayesian majority (50%) consensus rule tree based on combined partial LSU, SSU and ITS gene datasets. Bootstrap values from maximum parsimony (MP, left above), and maximum likelihood (ML, right above) of more than 60% are given above the nodes. Bayesian posterior probabilities (PP, below) of more than 0.95 are given below the nodes. The tree is rooted to Didymella exigua (CBS183.55). Muriphaeosphaeria galatellae (strain MFLUCC 14−0614) is indicated in red bold. The type species of each genus is indicated in blue bold, ex-type strains are bold.

FIGURE 2. Muriphaeosphaeria galatellae (MFLU 15–0087, holotype) A. Galatella villosa (L.) Rchb.f.summer.B. Superficial ascomata of sexual state (MFLUCC 14−0614). C. Conidiomata on host (MFLUCC 15−0769). Scale bars: B, C = 500 μm.

FIGURE 3. Muriphaeosphaeria galatellae (MFLU 15-0087, holotype) A. Superficial ascomata of sexual state on host. B. Close up of ascoma. C. Vertical section of ascoma. D. Section of papilla. E. Section through peridium. F. Pseudoparaphyses G. Immature ascus with ocular chamber. H–I. Mature asci. J–O. Ascospores. P. Germinating ascospore. Q. Culture characters on PDA, left from above. R. Conidiomata forming on bamboo pieces on WA after 8 weeks. S. Close up of conidiomata. T. Vertical section through conidiomata. U. Ostiole. V. Section through peridium. W–Z. Conidiogenous cells and developing conidia. AA–AG. Conidia. Scale bars: A = 500 μm, B, S, T = 200 μm, C = 100 μm, E, G–I, U–V = 50 μm, D, F = 20 μm, J–O, X–Z, AA–AG = 10 μm, W = 5 μm.