Bisifusarium sechiicola K. Zhang & Crous, 2025

Bisifusarium sechiicola K. Zhang & Crous , sp. nov. MB 858744 View Materials . Fig. 12.

Etymology: Name refers to Sechium , the host genus from which it was isolated.

Sporodochia greyish orange, formed abundantly on carnation leaves. Sporodochial conidiophores verticillately branched and densely packed; sporodochial phialides subulate to subcylindrical, 13–17 × 3–4 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, aseptate, hyaline, smooth- and thin-walled, (7.3–)8.0–11.0(–13.0) × (1.8–)2.0–2.5(–3.0) µm; aerial microconidia forming small false heads on tips of mono- and polyphialides, hyaline, ellipsoid to falcate, partially club-shaped, smooth- and thin-walled, aseptate, (4.4–)5.0–6.5(–7.0) × (1.5–)1.8–2.0(–2.3) µm. Chlamydospores not observed.

Culture characteristics: Colonies in the dark for 7 d at 25 °C: on OA reaching 4–4.5 cm diam., raised, aerial mycelia dense, colony margin entire, surface and reverse white. Colonies on PDA reaching 3.5–4 cm diam., raised, aerial mycelium dense, colony margin erose, surface and reverse white. Colonies on SNA reaching 3.5–4 cm diam., flat, aerial mycelium scant, colony margin erose, surface and reverse white; odour absent.

Typus: Mexico, Colima, from Sechium edule , 31 Oct. 2008, M. de J. Yáñez-Morales (holotype CBS H-25449 , culture ex-type CBS 153536 View Materials = CPC 16016 View Materials ) .

Notes: Bisifusarium sechiicola is morphologically and phylogenetically close to B. allantoides (macroconidia 9.5– 23.6 × 2.72–4.1 µm, av. 12.41 × 3.2 µm; Savaray et al. 2021), from which it differs by its smaller macroconidia, and white colonies on PDA, whereas those of B. allantoides are pale orange. Additionally, both species differ by 58 bp in the four loci dataset (ITS 3, rpb2 22, tef1 24, and tub2 9 bp).