Lasiodiplodia krabiensis Dayarathne, in Dayarathne, Jones, Maharachchikumbura, Devadatha, Sarma, Khongphinitbunjong, Chomnunti & Hyde, Mycosphere 11(1): 75 (2020)
Index Fungorum number: IF556586 Facesoffungi number: FoF 06173
Saprobic on submerged wood of Bruguiera sp. Asexual morph: Conidiomata pycnidial 680–740 × 300–360 μm (x̅ = 718 × 326.5 μm, n = 5), scattered to gregarious, immersed to semi immersed, conspicuous on host surface with a short neck, dark brown, solitary, uniloculate, globose to subglobose, ostiolate, papillate. Pycnidial wall 64–82 μm wide, composed of several layers of thick-walled, hyaline to dark brown cells of textura angularis. Paraphyses 20–51 μm wide, aseptate, hyaline, straight Conidiogenous cells 10–14 × 3–5.3 μm (x̅ = 13 × 3.6 μm, n = 20), annellidic, cylindrical, thick-walled, smooth. Conidia 24–26.8 × 13.2–16.6 μm (x̅ = 25. × 14 μm, n = 20), subglobose to oval, aseptate, hyaline to subhyaline with age, guttulate, without longitudinal striations and mucilaginous sheath. Sexual morph: unknown.
Culture characteristics: Conidia germinating on sea water PDA within 12 h. Colonies on seawater PDA, white at first, becoming black with age, circular, with entire edge, raised, velvety, black in reverse, with smooth margin.
Material examined: THAILAND, Krabi Province, Phang Nga, on decaying submerged wood of Bruguiera sp. (Rhizophoraceae), 30 August 2017, M.C. Dayarathne, MCD 142 (MFLU 17-2617, holotype); ibid., (HKAS102051, isotype), ex-type living culture (MFLUCC 17-2480).
GenBank numbers: ITS: MN047093; TEF: MN077070
Additional GenBank numbers: LSU: MN017859; SSU: MN017924
Notes: Lasiodiplodia krabiensis differs from its closest phylogenetic neighbor L. brasiliense by subglobose to oval conidia with rounded ends, while L. brasiliense comprises conidia mostly with a truncate base. Additionally, conidia of L. krabiensis are hyaline throughout the life cycle and conidia of L. brasiliense become brown with the age (Netto et al. 2014).
The base pair difference of the TEF locus is in the range of 2.5% (7 bp out of 280) and they can be considered as two distinct species using the guidelines of Jeewon & Hyde (2016). Lasiodiplodia bruguierae, which has been reported as an endophyte of Bruguiera gymnorhiza, is clearly different from this novel taxon by having brown pigmented conidia with striations (Osorio et al. 2016). We believe that both phenotypic and phylogenetic distinctness of this strain is sufficient to introduce it as a novel taxon within the genus Lasiodiploidia.