Botryosphaeriales » Botryosphaeriaceae » Lasiodiplodia

Lasiodiplodia swieteniae

Lasiodiplodia swieteniae Jayasiri, E.B.G. Jones & K.D. Hyde, in Jayasiri, Hyde, Jones, McKenzie, Jeewon, Phillips, Bhat, Wanasinghe, Liu, Lu, Kang, Xu & Karunarathna, Mycosphere 10(1): 143 (2019)


Index Fungorum number: IF555582

Facesoffungi number: FoF05296

Holotype: MFLU 18–2188

Etymology: Referring to the host genus on which the fungus was collected, Swietenia (Meliaceae).


Saprobic on fruit of Swietenia sp. Sexual morph: Undetermined. Asexual morph: Coelomycetous. Conidiomata 310–330 μm high × 300–370 μm diam. (x = 315 × 345 μm; n = 10), pycnidial, semi-immersed, solitary, rarely aggregated, dark brown to black, unilocular, with globose base. Conidiomata wall 33–51 μm wide (x = 46 μm; n = 20), outer layers composed of dark brown textura angularis, becoming thin-walled and hyaline toward the inner region; with brown, septate, hyphal hairs, with rounded tips covering the outer wall of fruiting body. Conidiophores reduced to conidiogenous cells. Conidiogenous cells 11–13 × 7–8.5 μm (x = 12 × 7.5 μm; n = 20), hyaline, smooth, thin-walled, discrete, phialidic, proliferating percurrently, arising from hyaline inner conidiomatal wall. Hamathecium 2–3 μm wide (x = 2.3 μm; n = 30), hyaline, aseptate, smooth, thin-walled, cylindrical, originating from the hyaline inner cells of conidiomata wall, with basal cells slightly swollen and apical cells rounded at tips. Conidia 24–32 × 11–14 μm (x = 30 × 13 μm; n = 30), initially hyaline, mature conidia turning dark brown, ellipsoid, with granular content, 1–3 septate.

Culture characters: Conidia germinated on MEA within 24 hr. Germ tubes produced from end of conidia. Colonies growing on MEA, reaching 60 mm diam. after 2 weeks at 18 ̊ C. Colonies with white fluffy mycelium, slightly dense and flattening at the centre, mycelium turning smoky- grey to olivaceous-grey, mycelium turning greenish olivaceous to black-olivaceous in reverse.

Material examined: THAILAND, Chiang Rai Province, Mae Fah Luang University, on decaying fruit pericarp of Swietenia sp. (Meliaceae), 15 January 2018, S.C. Jayasiri, C 425 (MFLU 18–2188, holotype; KUN-HKAS 102435, isotype), ex-type living culture MFLUCC 18–0244, KUMCC 18–0251.

GenBank numbers: SSU: MK347896, ITS: MK347789, LSU: MK348007, tef1: MK340870, tub2: MK412877

Notes: Lasiodiplodia swieteniae is in a clade sister to L. thailandica with high statistical support (83% MLBS/ 0.95 BYPP, Fig. 117) in multigene phylogenetic analysis of tef1 and tub2 genes. Base pair differences of the two species are 1 and 7 (2.0%) respectively, for tef1 and tub2 genes. Conidia of L. swieteniae differ from L. thailandica in having 1–3-septate, dark brown conidia without longitudinal striations (Trakunyingcharoen et al. 2015). Therefore, we introduce a new species based on molecular and morphological differences.