Cytospora thailandica Norphanphoun, T.C. Wen & K.D. Hyde

Norphanphoun, Chada, Raspe, Olivier, Jeewon, Rajesh, Wen, Ting-Chi & Hyde, Kevin D., 2018, Morphological and phylogenetic characterisation of novel Cytospora species associated with mangroves, MycoKeys 38, pp. 93-120 : 93

Cytospora thailandica Norphanphoun, T.C. Wen & K.D. Hyde sp. nov. Figure 4

Etymology.

refers to the country where the fungus was collected.

Holotype.

MFLU 17-0709

Associated with twigs and branches of Xylocarpus moluccensis . Sexual morph: Stromata immersed in bark. Ascostromata 400-1000 × 70-250 µm diameter, semi-immersed in host tissue, scattered, erumpent, uni- or multi-loculate, with ostiolar neck. Ostiole 70-150 µm diameter, numerous, dark brown to black, at the same level as the disc, occasionally area below disc a lighter entostroma. Peridium comprising several layers of cell of textura angularis, with innermost layer thick, brown, outer layer dark brown. Hamathecium comprising long cylindrical, cellular, anastomosed paraphyses. Asci (21 –)23– 25 × 4.1 –4.7(– 5) μm (x‒ = 22 × 4.3 μm, n = 15), 6-8-spored, unitunicate, clavate to elongate obovoid, with a J-, refractive apical ring. Ascospores (5.6 –)6– 6.8 × 1.3 –1.5(– 2) μm (x‒ = 6.6 × 1.5 μm, n = 20), biseriate, elongate-allantoid, unicellular, hyaline, smooth-walled. Asexual morph: Conidiomata 400-1200 × 180-380 µm diameter, semi-immersed in host tissue, solitary, erumpent, scattered, discoid, circular to ovoid, with multi-loculate, pycnidial, embedded in stromatic tissue, with ostiole. Ostioles 230-300 µm long, with an ostiolar neck. Peridium comprising few layers of cells of textura angularis, with innermost layer thin, pale brown, outer layer brown to dark brown. Conidiophores unbranched or occasionally branched at the bases, formed from the innermost layer of pycnidial wall, with conidiogenous cells. Conidiogenous cells (3.3 –)6– 9.1 × 1 –1.3(– 1.7) μm (x‒ = 6 × 1.3 μm, n = 15), blastic, enteroblastic, flask-shaped, phialidic, hyaline and smooth-walled. Conidia (3.3 –)3.8– 4 × 1 –1.3(– 1.5) µm (x‒ = 3.8 × 1.3 µm, n = 30), unicellular, subcylindrical, hyaline, smooth-walled.

Material examined.

THAILAND, Ranong Province, Ngao Mangrove Forest, on branches of Xylocarpus moluccensis , 6 December 2016, Norphanphoun Chada NG02a (MFLU 17-0709, holotype; PDD, isotype); ex-type-living cultures, MFLUCC 17-0262, MFLUCC 17-0263, ICMP.

Notes.

Cytospora thailandica was collected from branches of Xylocarpus moluccensis . The new species resembles some other Cytospora species, but is characterised by uni- or multi-loculate ascomata/conidiomata with unicellular, subcylindrical and hyaline spores in both morphs. Cytospora species associated with Xylocarpus granatum is also reported in this study as C. xylocarpi (MFLUCC 17-0251, Fig. 5). Cytospora xylocarpi is similar to C. thailandica in its conidiomata being multi-loculate and in the length of conidia in the asexual morph ( C. xylocarpi : conidia 3 × 1.1 µm versus 3.8 × 1.3 µm in C. thailandica ). However, C. thailandica differs from C. xylocarpi in having shorter ostiolar necks and larger asci and ascospores (Table 2). Phylogenetic analysis of our combined gene also reveals C. thailandica is closely related to C. lumnitzericola (Fig. 1), but there are nucleotide differences as mentioned in notes of C. lumnitzericola . The individual ITS1+ITS2 phylogenetic tree also indicates that C. thailandica is distinct with good support (Fig. 2).