Koorchaloma oryzae X.G. Tian & Tibpromma, 2021

Tian, Xingguo, Karunarathna, Samantha C., Mapook, Ausana, Xu, Jianchu, Bao, Danfeng, Promputtha, Itthayakorn & Tibpromma, Saowaluck, 2021, Koorchaloma oryzae sp. nov. (Stachybotryaceae, Sordariomycetes), from Oryza sativa (Poaceae) in northern Thailand, Phytotaxa 524 (4), pp. 283-292 : 288-289

Koorchaloma oryzae X.G. Tian & Tibpromma , sp. nov. ( Fig. 3 )

Index Fungorum number: IF 558491; Faces of fungi number: FoF 09906

Etymology —Referring to the host plant Oryza sativa , on which the fungus was collected.

Holotype: — THAILAND. Chiang Rai Province: Muang District , on dead leaves and culms of Oryza sativa , 22 October 2020, X. G. Tian r-3 – 3 ( MFLU 21 – 0047 , holotype), ex-type living culture, MFLUCC 21 – 0055 .

Saprobic on dead leaves and culms of Oryza sativa (Poaceae) . Sexual morph: undetermined. Asexual morph: Conidiomata 100–380 µm diam., yellow to brownish yellow, stromatic, shallow-cupulate, amphigenous, solitary, superficial, pulvinate, gelatinous, rounded to oval in outline, hyaline, occasionally elongate, stromata thin. Conidiomatal setae 170–300 µm long (x = 240 µm, n = 10), 5 – 10 μm wide (x = 7.5 µm, n = 10), dark brown at the base becoming hyaline towards the apex, apical cell inflated and showing percurrent growth, subcylindrical to cylindrical, straight or slightly curved, up to9-septate,unbranched,thick-walled. Conidiophores reduced to conidiogenous cells. Conidiogenous cells 7–12 × 2– 3 µm (x = 9.0 × 2.5 µm) (n = 20), subcylindrical or lageniform, hyaline, smooth-walled, discrete or sometimes integrated. Conidia 10–15 × 3–5 µm (x = 14.0 × 4 μm, n = 30), fusiform, hyaline, straight, smooth-walled, guttulate, aseptate, with an acute apex and a narrow truncate and often apiculate base, appendiculate with many setulae at the apex.

Culture characteristics: — Conidia germinating on PDA within 24 h at room temperature (25 ˚ C), colonies white, irregular, curled, wrinkled, spreading, and flat on surface, orange to white in reverse.

Notes: —Phylogenetic analyses of LSU, ITS and RPB 2 sequence data show that K. oryzae was placed within members of Koorchaloma and clustered with K. europaea . Koorchaloma oryzae is morphologically similar to K. europaea but can be distinguished by the conidiophores and conidia. Koorchaloma oryzae has fusiform conidia and conidiophores reduced to conidiogenous cells with many setulae at conidia apex, while K. europaea has macronematous conidiophores that are erect, branched at the base, hyaline, some reduced to conidiogenous cells, and naviculate conidia. The conidial appendage (appendiculate with many setulae) of K. oryzae is similar to K. europaea , K. krabiense , K. madreeya , and K. okamurae . Other species ( K. bambusae , K. galateae , K. jamaicensis , K. novojournalis , K. occidentale , K. scutiae and K. spartinicola ) have a funnel-shaped, mucoid appendage at each end. Hence, we introduce K. oryzae as a new species based on morphological characteristics and molecular data. A synopsis for the 13 species in the genus is provided in Table 2.

Figures

FIGURE 3. Koorchaloma oryzae (MFLU 21–0047, holotype). a–c. Appearance of conidiomata on host substrate. d, e. Conidioma and setae. f–j. Conidiophores, conidiogenous cells and developing conidia. k. Colony cultures on PDA. l–p. Conidia. q. Germinated conidium. Scale bars: a = 1000 µm, b–d = 200 µm, e = 100 µm, f–j, l–q = 10 µm.