Neogregarithecium sichuanense W.H. Tian, K.D. Hyde & Maharachch., in Tian, Liu, Jin, Chen, Zhou, Wu, Su, Guo, Wanasinghe, Hyde, Liu & Maharachchikumbura, Mycosphere 15(1): 1809 (2024)

Index Fungorum number: IF 851876; MycoBank number: MB 851876; Facesoffungi number: FoF16270

Etymology – Named after the Sichuan province, China, where the holotype was collected.

Holotype – HKAS 131988

Saprobic on the dead twigs of grass. Asexual morph: Hyphomycetous. Colonies on natural substratum velvety, superficial, black. Aerial hyphae septate, dark brown, verrucose. Conidiophores micronematosa, mononematous, arising laterally from superficial hyphae, simple or occasionally branched, aseptate, hyaline to pale brown, becoming paler or subhyaline towards the apex, verrucose, cylindrical to ampulliform, straight to slightly flexuous, 5–10 × 3–4 μm (x̅ = 6 × 3.5 μm, n = 25). Conidiogenous cells polyblastic, discrete, unbranched, straight, hyaline to pale brown, verrucose, inflated, 5–9 × 3–4 μm (x̅ = 6 × 3.5 μm, n = 25). Conidia holoblastic, acrogenous, catenate, 1–4 short acropetal chains, golden-brown to dark brown, verrucose, aseptate, globose, 3.5–4.5 μm (x̅= 4 μm, n = 30) diam., with single germ pore 1–2 μm (x̅= 1.7 μm, n = 20) diam.; conidial secession schizolytic. Sexual morph: Undetermined.

Material examined – China, Sichuan Province, Chongzhou city, Baiyungou, N 30°47’56”, E 103°24’15”, elevation 990 m, 27 September 2022, on dead twigs of grass, W.H. Tian lu59_2 (HKAS 131988, holotype).

GenBank numbers – ITS: PP294645, LSU: PP213252, SSU: PP213256, tef1-α: PP213051

Notes – Neogregarithecium sichuanense and Gregarithecium bambusae have different morphologies (see notes under Neogregarithecium), and differ in the size of conidiophores (5–10 × 3–4 μm vs. 10–48 × 3–5 μm). We could not obtain a culture from Neogregarithecium sichuanense, and DNA was extracted directly. Based on pairwise nucleotide comparisons, N. sichuanense differs from G. bambusae by 45/450 bp (gaps: 15/450 bp) in ITS; 18/769 bp (gaps: 7/769 bp) in LSU; 10/1024 bp (no gaps) in SSU; 35/404 bp in tef1-α. Thus, our collection HKAS 131988 was identified as a new genus based on morphological observation and phylogenetic evidence.

Figure 1 – Neogregarithecium sichuanense (HKAS 131988, holotype). a Specimen. b, c Mycelium on the host surface. d–f Conidiophores with lateral conidia. g, h Developing conidia in short acropetal chains. i–k Conidia. Scale bars: d = 100 μm, e–k = 10 μm.