Curvularia beasleyi 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 beasleyi Y.P. Tan & R.G. Shivas sp. nov. Fig. 2 A–D

Type.

Australia, Queensland, Beaudesert, from leaf spot on Chloris gayana , 9 Jan. 1974, J.L. Alcorn (holotype BRIP 10972, includes ex-type culture).

Description.

Colonies on PDA approx. 4 cm diam. after 7 d at 25 °C, surface funiculose, margin fimbriate, olivaceous black. Hyphae subhyaline, smooth to branched, septate, up to 3 µm in width. Conidiophores branched, erect, straight to flexuous, geniculate towards apex, brown, paler towards apex, smooth, septate, up to 110 µm long, 4 µm wide; basal cell swollen and darker than the other cells, up to 6 µm diam. Conidiogenous cells integrated, terminal or intercalary, sympodial, pale brown, smooth, with darkened scars. Conidia fusiform, straight to slightly curved, rounded at the apex, (14-) 26-29 (-34) × (5-) 6.5-7.5 (-9) µm, brown to dark brown, 3-7 (mostly 5)-distoseptate; hila conspicuous, slightly protuberant, thickened and darkened, 1−1.5 µm wide.

Etymology.

In recognition of Dr Dean R. Beasley, an Australian plant pathologist, for his dedication and numerous innovative contributions to the curation and promotion of the Queensland Plant Pathology Herbarium (BRIP).

Additional material examined.

Australia, Queensland, Atherton, from leaf spot on Leersia hexandra , 1 May 1987, J.L. Alcorn, BRIP 15854 (includes culture).

Notes.

Curvularia beasleyi is placed in the same clade as C. dactyloctenii , C. hawaiiensis and C. nodosa (Fig. 1). Curvularia dactyloctenii and C. hawaiiensis have been recorded in Australia ( Sivanesan 1987, Tan et al. 2014), but the recently described C. nodosa has only been reported from Thailand ( Marin-Felix et al. 2017b). Curvularia beasleyi is distinguished in two loci from the ex-type cultures of C. dactyloctenii (99% in gapdh and 99% in tef1α), C. hawaiiensis (98% in gapdh and 99% in tef1α) and C. nodosa (99% in gapdh and 99% in tef1α). The conidia of C. beasleyi are longer than those of C. nodosa (12-25 µm, Marin-Felix et al. 2017b) and shorter than those of C. dactyloctenii (32-55 µm, Sivanesan 1987). Curvularia beasleyi is morphologically similar to C. hawaiiensis , however the later species has never been recorded on Leersia ( Farr and Rossman 2018).

Curvularia beasleyi is only known from Queensland on two unrelated grasses, the introduced host Chloris gayana and the native Leersia hexandra . There are many Curvularia species reported as associated with Chloris spp. ( C. australiensis , C. australis , C. hawaiiensis , C. lunata , C. nodosa , C. pallescens , C. tsudae , C. variabilis , C. verruculosa ) ( Sivanesan 1987, Deng et al. 2014, Manamgoda et al. 2014, Marin-Felix et al. 2017b) and Leersia spp. ( C. australiensis , C. geniculata , and C. heteropogonicola ) ( DAF Biological Collections 2018, Farr and Rossman 2018, Herbarium Catalogue 2018), although not all of the reports have been verified by molecular phylogenetic analyses.