Curvularia beerburrumensis 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 beerburrumensis Y.P. Tan & R.G. Shivas sp. nov. Fig. 2 E–I

Type.

Australia, Queensland, Beerburrum, from blackened inflorescence of Eragrostis bahiensis , 24 May 1979, J.L. Alcorn (holotype BRIP 12942, includes ex-type culture).

Description.

Colonies on PDA approx. 2 cm diam. after 7 d at 25 °C, surface funiculose, margin fimbrillate, olivaceous black. Hyphae subhyaline, smooth to asperulate, branched, septate, 3−4 µm in width; chlamydospores intercalary in chains, 4-9 µm, smooth, thick-walled. Conidiophores erect, straight to flexuous, geniculate towards apex, subhyaline to pale brown, smooth, septate, up to 500 µm long, 5−6 µm wide. Conidiogenous cells integrated, terminal or intercalary, with sympodial proliferation, pale brown to brown, smooth, mono- or polytretic, with darkened scars. Conidia fusiform to subcylindrical or clavate, straight to slightly curved, rounded at the apex, (40-) 51-56 (-71) × (10-) 12-13 (-14) µm, subhyaline to pale yellowish-brown, 2-4 (mostly 3)-distoseptate; hila mostly inconspicuous or minutely thickened and darkened.

Etymology.

Named after the town Beerburrum, where the holotype was collected.

Additional material examined.

Australia, Queensland, Beerburrum, New South Wales, Yetman, blackened inflorescence of Eragrostis sororia , 12 May 1977, J.L. Alcorn, BRIP 12555 (includes culture).

Notes.

Curvularia beerburrumensis is phylogenetically sister to C. australis and C. ovariicola (Fig. 1), which have both been recorded in Australia on Eragrostis ( Sivanesan 1987, Tan et al. 2014). Curvularia beerburrumensis is distinguished from the ex-type culture of C. australis in three loci (98% in ITS, 96% in gapdh and 98% in tef1α). Furthermore, C. beerburrumensis has larger conidia than C. australis (25−48 × 9.0−12.5 µm, Sivanesan 1987). Curvularia beerburrumensis differs from the ex-type culture of C. ovariicola in three loci (99% in ITS, 99% in gapdh and 99% in tef1α). Curvularia beerburrumensis has longer conidiophores than C. ovariicola (up to 325 µm, Sivanesan 1987). Curvularia beerburrumensis also produced chlamydospores in culture, which are not known for C. australis and C. ovariicola .

Curvularia beerburrumensis is only known from inflorescences of the invasive South American grass Eragrostis bahiensis , as well as the Australian native E. sororia ( Simon and Alfonso 2011). Other Curvularia associated with Eragrostis include C. australis , C. clavata , C. crustacea , C. ellisii , C. eragrostidis , C. geniculata , C. kusanoi , C. lunata , C. miyakei , C. nodulosa , C. ovariicola , C. perotidis , C. protuberata , C. ravenelii and C. verrucosa , ( Sivanesan 1987, Farr and Rossman 2018, Herbarium Catalogue 2018), although many of these reports are yet to be verified by molecular phylogenetic analyses.