Arthrinium dichotomanthi M. Wang & L. Cai

Wang, Mei, Tan, Xiao-Ming, Liu, Fang & Cai, Lei, 2018, Eight new Arthrinium species from China, MycoKeys 34, pp. 1-24 : 3

Arthrinium dichotomanthi M. Wang & L. Cai sp. nov. Figure 5

Type.

CHINA, Chongqing, on Dichotomanthus tristaniaecarpa , 20 Dec. 2012, L. Cai, (holotype: HMAS 247185; culture ex-type: CGMCC 3.18332 = LC4950).

Etymology.

Named after the host from which it was isolated.

Description.

Hyphae hyaline, branched, septate, 1.5-5.0 μm diam. Conidiophores reduced to conidiogenous cells. Conidiogenous cells erect, aggregated in clusters on hyphae, hyaline to pale brown, smooth, doliiform to clavate or lageniform, 5.5-11.0 × 3.0-5.0 μm (x̄ = 7.9 ± 1.4 × 4.0 ± 0.5, n = 30). Conidia brown to dark brown, smooth to finely roughened, globose, subglobose to lenticular, with a longitudinal germ slit, 9.0-15.0 × 6.0-12.0 μm (x̄ = 12.0 ± 1.4 × 8.5 ± 1.1, n = 50).

Culture characteristics.

On PDA, colonies umbonate, margin irregular, with sparse aerial mycelia. Colonies creamy-white to greyish without patches reverse, reaching 9 cm in 7 days at 25 °C. On MEA, colonies flat, spreading, surface and reverse pale luteous.

Other specimens.

CHINA, Chongqing, on Dichotomanthus tristaniaecarpa , 20 Dec. 2012, L. Cai, living culture LC8175 = WM529; ibid. living culture LC8176 = WM 530.

Notes.

Three strains representing A. dichotomanthi formed a distinct clade closely related to A. phaeospermum (Corda) M.B. Ellis (99% sequence similarity in ITS; 96% in TUB2; 96% in TEF1), A. serenense Larrondo & Calvo (99% sequence similarity in ITS; 95% in TUB2) and A. saccharicola F. Stevens (99% sequence similarity in ITS; 95% in TUB2; 97% in TEF1). Arthrinium dichotomanthi differs from A. phaeospermum and A. saccharicola in its larger conidia (globose or subglobose, 9.0-15.0 × 6.0-12.0 μm in A. dichotomanthi vs. surface view (9 –)10(– 12) μm diam, side view 6-7 μm diam in A. phaeospermum , surface view (7 –)8–9(– 10) μm diam, side view (4 –)5(– 6) μm diam in A. saccharicola ) and from A. serenense by the absence of odour on the MEA colony (Larrondo 1990).