Bipolaris dracaenicola (Chaiwan& Hyde) (DNC1.1), new species Nitschke (Dimu)
MycoBank number: MB; Index Fungorum number: IF; Facesoffungi number: FoF 10759; Fig. **.
Etymology – Referring to the host genus on which the fungus was collected, Dracaena (Asparagaceae).
Saprobic on dead stems of Dracaena sp. Sexual morph: Undetermined. Asexual morph: Vegetative hyphae septate, subhyaline to brown, branched, smooth, 3–4 μm in width. Conidiophores erect, simple in most cases uniformly brown, sometimes pale brown at apex. Bipolaris are micronematous to semi-macronematous, arising singly, septate, flexuous, in most cases geniculate towards the apex, up to 210 μm long, 3–4 μm wide, generally equal wide in basal parts, tapering in median and upper parts, geniculate in apex, cells walls thicker than those of the vegetative hyphae, basal cells sometimes swollen. Conidiogenous cells mostly integrated, terminal, or intercalary with sympodial proliferation, smooth, brown, mono- or polytretic. Chlamydospores with verruculose nodes, terminal or intercalary, proliferating sympodially, with circular and thickened scars, brown, cylindrical to swollen. Conidia with germination pattern at last, smooth-walled or slightly verruculose, asymmetrically swollen and curved at the third cell from base, rarely symmetric swelling and straight, pale to dark brown, end cells paler and thin-walled than central cells, ellipsoidal to clavate to obovoid, asymmetrical with paler end cells, usually curved at the third cell from the base, 1-4 celled, hila slightly protuberant, thickened and darkened, Germination Bipolar.
Cultural characters – Colonies growing on PDA 4–6 cm diam after 8 d incubation at 25 °C, circular with filiform margin, olivaceous black, aerial mycelium sparse to moderate, floccose with age; reverse greyish green to brownish black.
Material examined – Thailand, Chiang Rai Province, Mea Lao distric, on dead leaves of Dracaena sp., 17 November 2017, Napalai Chaiwan, DNC1.1 (MFLUCC T20-1612, holotype). Ex type culture??
Host – Dracaena fragrans
Distribution – Thailand (This study).
GenBank accession numbers – MFLU **; ITS: ***; GAPDH: waiting; TEF1: ***
Notes – Single and combined phylogenetic analysis of the Bipolaris generic complex. This section provides descriptions and illustrations of new species based on molecular and morphological data (Manamgoda et al. 2012, Bhunjun et al. 2020). The details of the specimens and notes on host distribution are provided. The phylogenetic analysis of combined ITS, GPDH and TEF gene regions comprises 108 isolates including the outgroup taxon (Fig. 1). The RAxML combined phylogenetic tree using three genes illustrate the phylogeny of the genus (Fig. 1). The Bayesian and Likelihood combined analyses produce phylogenetic trees with log likelihood values -11998.1 and -11920.2, respectively. The combined analysis showed the separate clade of our new species in Bipolaris. Twenty-three taxa of Bipolaris used in the analysis. This new species were isolated from Dracaena fragrans plant hosts for the first time in this study.
Figure ***– Bipolaris dracaenicola (MFLUCC 17–2600, herbarium). a–b Appearance of mycelium on culture. c,g Conidiophored d Conidiogenous cells arise from conidiophore. f an immature conidia i–j. Conidiogenous cell h. Conidia Scale bars: c=20 μm. a,b,d,g,h=10 μm. f=5 μm. e=1 μm.