Curvularia sporobolicola 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 sporobolicola Y.P. Tan & R.G. Shivas sp. nov. Fig. 5 C–E

Type.

Australia, Queensland, Musselbrook Reserve, leaf of Sporobolus australasicus , 2 May 1995, J.L. Alcorn (holotype BRIP 23040b, includes ex-type culture).

Description.

Colonies on PDA approx. 6 cm diam. after 7 d at 25 °C, surface funiculose, margin fimbriate, olivaceous black, velutinous. Hyphae subhyaline, smooth, branched, septate, 3 µm wide. Conidiophores erect, straight to flexuous, geniculate, pale yellowish-brown, septate, up to 55 µm long, 4−5 µm wide, basal cell swollen, 6−10 µm diam. Conidiogenous cells cylindrical, slightly flared at the apex, integrated, sympodial, pale brown, smooth, with darkened and thickened scars. Conidia hemi-ellipsoidal, curved, 4-distoseptate with a faint narrow median septum, (34-) 37-41 (-45) × (14-) 17-20 (-23) µm, brown to dark brown, end cells rounded and paler, hila non-protuberant, sometimes darkened.

Etymology.

Named after Sporobolus , the grass genus from which it was isolated.

Notes.

Based on multilocus phylogenetic analyses, C. sporobolicola clustered sister to C. papendorfii , which are both sister to C. eragrosticola (Fig. 1). Curvularia sporobolicola is distinguished in three loci from the ex-type cultures of C. papendorfii (99% in ITS, 96% in gapdh and 98% in tef1α) and C. eragrosticola (98% in ITS, 92% in gapdh and 98% in tef1α). These three species are similar in having dark brown, hemi-ellipsoidal, curved, conidia, which makes identification by morphology difficult. The conidia of C. sporobolicola tend to be wider than those of C. eragrosticola (25-35 × 9-19 µm, this study) and C. papendorfii (30-50 × 9-19 µm, Sivanesan 1987).

Curvularia sporobolicola is only known from the type specimen on S. australasicus , which is a native Australian grass with a broad distribution in the tropics and subtropics ( Simon and Alfonso 2011). Other Curvularia species associated with Sporobolus include C. australis , C. crustacea , C. eragrostidis , C. geniculata , C. lunata , C. ovariicola , C. pallescens , C. ravenelii and C. ryleyi ( Sivanesan 1987, Farr and Rossman 2018), although this is the first Curvularia species associated with S. australasicus .