Lasiodiplodia dracaenae Chaiwan & K.D. Hyde, sp nov.
MycoBank number: MB; Index Fungorum number: IF; Facesoffungi number: FoF 10753;
Holotype – MFLU 18–****
Etymology – Referring to the host genus on which the fungus was collected, Dracaena (Asparagaceae).
Saprobic on dead leaves of Dracaena fragrans. Sexual morph: Undetermined. Asexual morph: Conidiomata 200–250 μm high× 100–130 μm diam. (x̅= 225×115 μm n = 10), pycnidial, semi-immersed, unilocular, solitary, scattered, globose or subglobose, dark brown. Conidiomata wall 25–40 μm wide, outer layers dark brown to black, thickwalled, inner layers thin-walled, pale brown to hyaline, comprising 2–3 layers of dark brown cells of textura angularis. Paraphyses up to 30 μm long, 1–2 μm wide, hyaline, septate, cylindrical, occasionally branched, ends rounded. Conidiogenous cells holoblastic, hyaline, thin-walled, smooth, cylindrical. Conidiogenous cells 18–22× 6–9 μm (x̅ = 20 × 7.5 μm n= 15), holoblastic, hyaline, cylindrical. Conidia 10–25 μm×9–10 μm (x̅ = 17.5×9.5 μm n=30), initially hyaline and aseptate when immature, becoming medianly 1-euseptate, dark brown, thick-walled, ellipsoid to obovoid, base truncate or rounded, with longitudinal striations from apex to base.
Material examined – THAILAND, Krabi Province, *** District, on dead leaves of Dracaena fragrans, 21 December 2018, Napalai Chaiwan, Krabi1, MFLU 20–***.
Host – Known to inhabit fruits, leaves and stems of multiple plant genera in multiple families (Farr et al. 2016) and dead leaves of Dracaena fragrans. (current study).
Distribution – Widely distributed in tropical and subtropical regions (Farr et al. 2016).
GenBank accession number – ITS: ***, RPB2: waiting sequence, TEF1:***, TUB: waiting sequence
Notes – Phylogenetic analyses of L. dracaenae (MFLUCC 12–****) groups it with L. lignicola (Auerswaldia lignicola =Lasiodiplodia lignicola) in Liu et al. (2012). However our new species is the first report from Dracaena fragrans in Thailand. Therefore, details are provided of this species to facilitate identification on this host. The morphology of this collection is similar to L. theobromae (MFLU 15–0730) in Doilom et al. 2016. A comparison of the ITS nucleotides of these new species reveals 8/594 (0.013%) nucleotide differences and the TEF nucleotides of these new species reveals 146/970 (0.150%) nucleotide differences, which indicates that they are distinct taxa (Jeewon & Hyde 2016).
Figure***– Lasiodiplodia dracaenae (Krabi1) a–b. Fruitingbody on dead leaves of Dracaena fragrans. c. Section through conidioma d–e. Peridium (Conidioma wall) f–g. Conidiogenous cells h–i. Paraphyses j–n. Conidia o–t. Mature conidia Scale bars: a=2000 μm. b=500 μm. c, g, i=20 μm. d, f, h,j–m=10 μm. d, e=5 μm.