Curvularia mebaldsii Y.P. Tan & R.G. Shivas

Tan, Yu Pei, Crous, Pedro W. & Shivas, Roger G., 2018, Cryptic species of Curvularia in the culture collection of the Queensland Plant Pathology Herbarium, MycoKeys 35, pp. 1-25 : 1

Curvularia mebaldsii Y.P. Tan & R.G. Shivas sp. nov. Fig. 4 A–C

Type.

Australia, Victoria, Hopetoun, from Cynodon transvaalensis , Apr. 1979, M. Mebalds (holotype BRIP 12900, includes ex-type culture).

Description.

Colonies on PDA approx. 5 cm diam. after 7 d at 25 °C, surface funiculose, margin fimbriate, olivaceous black with white patches, velutinous with some aerial mycelium. Hyphae hyaline to subhyaline, smooth to asperulate, septate, 3-4 µm wide. Conidiophores erect, straight to flexuous, sometimes slightly geniculate towards apex, branched, uniformly brown, paler at apex, smooth to asperulate, septate, up to 180 µm long, 4-5 µm wide. Conidiogenous cells integrated, terminal or intercalary, with sympodial proliferation, subhyaline to pale brown, smooth, mono- or polytretic, with darkened scars. Conidia ellipsoidal to obovoid, sometimes straight to slightly curved, rounded at the apex, (22-) 25-28 (-30) × (7-) 8-9 (-10) µm, pale brown to brown, 3-distoseptate, hila protuberant, thickened and darkened, 1-2 µm wide.

Etymology.

Named after the collector, Martin Mebalds, in recognition of his contributions to Australian plant pathology and biosecurity.

Additional material examined.

Australia, New South Wales, Tweed Heads, from necrotic leaf on Cynodon dactylon x transvaalensis , 10 Jun. 1983, G. Thomas, BRIP 13983 (includes culture).

Notes.

The multilocus phylogenetic analyses showed that C. mebaldsii was sister to C. tsudae , although separated by a considerable genetic distance (Fig. 1). Curvularia mebaldsii is distinguished from the ex-type culture of C. tsudae in three loci (98% in ITS, 97% in gapdh and 99% in tef1α). Morphologically, C. mebaldsii cannot be reliably separated from C. tsudae .

Curvularia mebaldsii is known from two specimens on Cynodon spp. Several Curvularia species have been associated with Cynodon , including C. aeria , C. australiensis , C. brachyspora , C. clavata , C. fallax , C. geniculata , C. hawaiiensis , C. inaequalis , C. lunata , C. pallescens , C. ramosa , C. senegalensis , C. spicata , C. spicifera and C. verruculosa ( DAF Biological Collections 2018, Farr and Rossman 2018, Herbarium Catalogue 2018), although these records have not been verified by phylogenetic analyses.