Bisifusarium australianum K. Zhang & Crous, 2025

Zhang, K., Sandoval-Denis, M., Kandemir, H., Yilmaz, N., Groenewald, J. Z., Yáñez-Morales, M. de J., Wingfield, M. J. & Crous, P. W., 2025, Taxonomic revision of Bisifusarium (Nectriaceae), Persoonia 54 (1), pp. 197-223 : 208

Bisifusarium australianum K. Zhang & Crous , sp. nov. MB 858738 . Fig. 4.

Etymology: Name refers to Australia, where it was collected.

Sporodochia greyish orange, formed abundantly on CLA. Sporodochial conidiophores verticillately branched and densely packed; sporodochial phialides subulate to subcylindrical, 15–20 × 2–3.5 µm, smooth- and thin-walled. Sporodochial macroconidia slender, falcate, slightly curved with almost parallel sides tapering slightly towards both ends, with a papillate to hooked, curved apical cell and a blunt to poorly developed foot-like basal cell, 1-septate, hyaline, smooth- and thin-walled, (11.5–)12.0–13.5(–15.0) × (2.0–)2.5–3.0(–3.6) µm. Aerial conidiophores 30–50 µm tall, often reduced to single monophialides; aerial phialides subulate to subcylindrical, smooth- and thin-walled, 20–29 × 2–3 µm; Chlamydospores not observed.

Culture characteristics: Colonies in the dark for 7 d at 25 °C: on OA reaching 4.5–5 cm diam., raised, aerial mycelium dense, colony margin entire, surface and reverse white. Colonies on PDA reaching 4–4.5 cm diam., raised, aerial mycelium dense, colony margin erose, surface and reverse white. Colonies on SNA reaching 4.5–5 cm diam., flat, aerial mycelium scant, colony margin erose, surface and reverse white; odour absent.

Typus: Australia, from poultry feed, collection date and collector unknown, isol. M.D. Connole, dep. C. Booth (holotype CBS H-25445 , culture ex-type CBS 366.73 = ATCC 16553 = ATCC 24368 = IMI 117087 b = NRRL 20712 ) .

Notes: Bisifusarium australianum is phylogenetically closely related to B. aseptatum . Morphologically, B. australianum is distinguished from B. aseptatum in macroconidial septation (1-septate in B. australianum vs aseptate in B. aseptatum ). Additionally, both species differ by 213 bp in the combined alignment (ITS 38, rpb2 48, and tef1 127, while tub2 are lacking for B. australianum ).