Submultiguttulispora multiseptata J. Y. Zhang, K. D. Hyde & Y. Z. Lu, 2025

Submultiguttulispora multiseptata J. Y. Zhang, K. D. Hyde & Y. Z. Lu sp. nov.

Fig. 3 View Figure 3

Etymology.

The name refers to the multi-septate conidia of the new species.

Holotype.

HKAS 129868 View Materials .

Description.

Saprobic on a dead wood log by a stream. Sexual morph undetermined. Asexual morph Hyphomycetous. Colonies on natural substrate superficial, effuse, single, or gregarious, arise in groups from knots of hyphal cells, brown to black. Mycelium partly superficial, partly immersed, composed of septate, pale brown to brown, smooth-walled hyphae. Conidiophores 285–385 (– 533) µm long × 5–7 µm wide at the base (x ̄ = 341 × 6 µm, n = 15), macronematous, mononematous, single or clustered in groups, erect, straight or flexible, unbranched, septate, smooth, guttulate, dark brown or black at the base, becoming pale brown towards the apex. Conidiogenous cells 64.5–100 × 4.3–6.1 µm (x ̄ = 80.2 × 5.2 µm, n = 15), mono- to polyphialidic, with discrete, terminal to lateral phialides, integrated, terminal, with lateral openings formed by successive sympodial elongation, cylindrical to cylindrical – lageniform, with funnel-shaped collarettes, smooth-walled, guttulate, brown at the base and becoming pale brown to subhyaline towards the apex. Conidia 33–40 × 7.5–9 µm (x ̄ = 36.6 × 8.3 µm, n = 20), acropleurogenous, 5 (– 6) - septate, not constricted at the septum, pale brown to olive green to brown, with subhyaline cells at both ends, straight, sometimes slightly curved, occasionally guttulate, fusiform, or ellipsoidal-fusiform, with a filiform, short and hyaline appendage at each end.

Culture characteristics.

Conidia germinating on WA within 15 h and germ tube produced from conidia. Colonies growing on PDA, reaching 35–40 mm diameter in 15 days at 26 ° C, circular with slightly irregular edge, flat with a protuberance in the center, dry, velvety, zonate, tephrosiousto to grey from center to margin; dark brown or black from below.

Material examined.

China • Hainan Province, Wuzhishan City, Wuzhishan Tropical Rainforest Scenic Area , on a dead wood log by a stream, 15 August 2021, J. Y. Zhang, WZ 44-1 ( HKAS 129868 View Materials , holotype; GZAAS 23–0763 , isotype); ex-type living cultures, KUNCC 23–14145 .

Notes.

Based on a BLASTn search in GenBank, the ITS and LSU sequences of our new collection show 91.92 % and 95.35 % similarity to Phialogeniculata guadalcanalensis ( NN 044662) and Multiguttulispora triseptata ( IMI 353690), respectively. The phylogenetic tree indicates that our new isolate forms a distinct lineage closely related to Multiguttulispora , without statistical support. This lack of support may be attributed to the absence of molecular sequences of many close phylogenetic relatives, which remain undiscovered ( Hyde et al. 2024 c). Submultiguttulispora shares similarities with Multiguttulispora in the absence of setae and the presence of macronematous conidiophores with polyphialidic conidiogenous cells that exhibit sympodial extension. Both genera produce septate conidia with a filiform, hyaline appendage at each end. However, Submultiguttulispora is distinguished from Multiguttulispora by its fusiform or ellipsoidal-fusiform, dematiaceous conidia, whereas the conidia of Multiguttulispora are cylindrical, oblong, and hyaline. Based on these morphological and phylogenetic differences, a new genus, Submultiguttulispora , is introduced to accommodate our new isolate, S. multiseptata .