Curvularia warraberensis 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 warraberensis Y.P. Tan & R.G. Shivas sp. nov. Fig. 5 F–H

Type.

Australia, Queensland, Torres Strait, Warraber Island, from leaf spot on Dactyloctenium aegyptium , 2 Jun. 1985, R.A. Peterson (holotype BRIP 14817, includes ex-type culture).

Description.

Colonies on PDA 6-7 mm diam. after 7 d at 25 °C, surface funiculose, margin fimbriate, olivaceous green, velutinous with some aerial mycelium. Hyphae subhyaline, smooth, septate, up to 3 µm wide. Conidiophores erect, flexuous, geniculate towards apex, uniformly pale brown to brown, septate, up to 360 µm long, 4-5 µm wide, basal cell sometimes swollen, 6-8 µm diam. Conidiogenous cells integrated, terminal or intercalary, with sympodial proliferation, pale brown to brown, smooth, mono- or polytretic, with darkened scars. Conidia ellipsoidal, curved, the third cell from base swollen, end cells paler, smooth, (20-) 23-26 (-28) × (8-) 9.5-11 µm, pale brown to brown, 3-distoseptate, hila conspicuous, sometimes slightly protuberant, thickened and darkened.

Etymology.

Named after the locality, Warraber Island in the Torres Straits, where the specimen was collected.

Notes.

Multilocus phylogenetic analyses placed C. warraberensis sister to C. caricae-papayae and C. prasadii (Fig. 1). Curvularia warraberensis differs from the ex-type culture of C. caricae-papayae in gapdh positions 40 (C), 102 (C), 230 (A), 233 (C) and 321 (A) and from the ex-type culture of C. prasadii in two loci, gapdh positions 102 (C), 131 (C), 230 (A), 233 (C), 321 (A) and tef1α positions 214 (C), 337 (C), 542 (A), 543 (C), 685 (C). These three species belong to the lunata-clade sensu Madrid et al. (2014), which also includes C. aeria , C. brachyspora , C. chlamydospora , C. lunata and C. pseudolunata . All the species in the lunata-clade sensu Madrid et al. (2014) have 4-celled conidia in which the third cell from the base is often swollen (unequally sided and larger) and darker than the other cells. Curvularia warraberensis has longer conidiophores than C. caricae-papayae (up to 100 µm long, Srivastava and Bilgrami 1963) and longer conidia than C. caricae-papayae (12.8-18.0 × 6-8 µm) and C. prasadii (12.8-18.0 × 6-8 µm, Mathur and Mathur 1959).

Curvularia warraberensis is only known from the holotype. Curvularia species associated with Dactyloctenium are listed in the notes for C. petersonii .