Bisifusarium undefined-1

Bisifusarium sp. 1. Fig. 13. Sporodochia greyish orange, formed abundantly on SNA and CLA. Sporodochial conidiophores verticillately branched and densely packed, giving rise to 1–2 conidiogenous cells, 10–30 × 2–3 µm; sporodochial phialides subulate to subcylindrical, smooth- and thin-walled, 2–4 µm diam. Sporodochial macroconidia slender, falcate, slightly curved with almost parallel sides tapering slightly towards both ends, with a papillate to hooked, curved apical cell and well-developed foot-like basal cell, 2-septate, with septa a third up from hilum and down from apex, not median, hyaline, smooth- and thin-walled, (14.5–)15.0–17.0(–18.9) × (2.3–)2.5–3.0(–3.5) µm. Microconidia not observed. Chlamydospores intercalary, solitary or in short chains, ellipsoid to cylindrical, 6–10 µm diam. Culture characteristics: Colonies in the dark for 7 d at 25 °C: on OA reaching 5.5–6 cm diam., raised, aerial mycelia dense, colony margin entire, surface and reverse white. Colonies on PDA reaching 7–8 cm diam., raised, aerial mycelia dense, colony margin erose, surface and reverse white. Colonies on SNA reaching 6–6.4 cm diam., flat, aerial mycelia scant, colony margin erose, surface and reverse white; pigment and odour absent. Material examined: Australia, cultivated soil, collection date and collector unknown, isol. L. Burgess, F 7749, culture CBS 110318 = FRC E-0300 = NRRL 36191. Notes: Bisifusarium sp. 1 was originally assigned to Fusarium sp. 3 by Schroers et al. (2009) and it is closely related to B. lovelliae (Tan & Shivas 2023a). Both lineages have identical ITS sequences, while rpb2 sequences are not available for Bisifusarium sp. 1. Both taxa differ by 51 bp in the combined alignment (tef1 39, and tub2 12 bp). Morphologically, Bisifusarium sp. 1 differs from its closest phylogenetic relatives (B. delphinoides, B. lovelliae and B. nectrioides) by the absence of microconidia, and its often well-developed macroconidial foot cells.