Pestalotiopsis loeiana Y.R. Sun & Yong Wang bis, in Sun, Jayawardena, Sun & Wang, Microbiology Spectrum: e03987-22, 14 (2023)

Index Fungorum number:IF 571226; MycoBank number: MB 571226; Facesoffungi number: FoF 12919;

Etymology – Refers to the collected site, Loei province.

Holotype – MFLU 22-0167

Saprobic on dead leaves. Sexual morph: Not observed. Asexual morph: Conidiomata solitary, black, semi-immersed on leaves. Conidiophores indistinct and conidiogenous cells indistinct. Conidia 17 and 22 × 4 and 6 μm (x̄ = 19 × 5 μm, n = 40), L/W ratio of 3.7, fusiform, straight to slightly curved, 4 septate; basal cell obconic with a truncate base, hyaline or sometimes pale brown, rugose walled, 3 to 6 μm long, with 1 to 3 basal appendages, unbranched, tubular, centric, 3 to 13 μm long (x̄ = 9 μm); three median cells 10 to 14 μm (x̄ = 12, n = 40), doliiform to cylindrical, brown, concolorous, wall rugose, septa darker than the rest of the cell, somewhat constricted at the septa; second cell from base brown, 3 to 6 μm long; third cell brown, 3 to 5 μm long; fourth cell brown, 2 to 5 μm long; apical cell 3 to 5 μm long, hyaline, conic to acute; with 1 to 3 tubular appendages on the apical cell, inserted at different loci in a crest at the apex of the apical cell, unbranched, 13 to 24 μm long.

Culture characteristics – Colonies on PDA reached 8 cm in diameter after 2 weeks at 25°C, colonies filamentous to circular, medium dense, mycelium on surface flat or raised, with filiform margin, fluffy, yellow circle in the middle surrounded by white mycelium from above, light yellow to pale brown from the reverse.

Material examined – Thailand, Loei Province, dead leaves of an identified plant, 27 February 2020, J.Y. Zhang, JY1 (MFLU 22-0167, holotype); ex-type culture, MFLUCC 22-0123.

Notes –Pestalotiopsis Loeiana (MFLUCC 22-0123) is phylogenetically related to P. rhizophorae and P. thailandica, which were isolated from leaf spots of mangroves (Fig. 11). P. loeiana has a similar conidial size to P. rhizophorae and P. thailandica. However, P. loeiana is distinguishable by its more than one basal appendage. The result of the PHI test (Фw = 0.2881) also showed there is no significant recombination between P. loeiana and its closely related taxa (Fig 12b). Therefore, we introduce P. loeiana as a new species.

Figure 14 – Pestalotiopsis loeiana (MFLU 22-0167, holotype). a, b Conidiomata on the host. c–h Conidia. i Germinated conidium. j, k Colonies on PDA. Scale bars: a = 500 µm, b = 200 µm, c–i = 10 µm.