China, Xinjiang, soil, 2002, isolated by L. Cai, Holotype CBS H-22837, culture ex-holotype CBS 141839 = DTO 340-G5.

MN864276. Alternative identification markers: BenA = MN863345, CaM = MN863322, RPB2 = MN863334.

Talaromyces albisclerotius produces white sclerotia on OA, grows restrictedly on CYA, YES, DG18 and OA and does not grow on CYAS.

Talaromyces section Trachyspermi

CYA 5–8; CYA 30 °C 3–4; CYA 37 °C No growth; MEA 19–20; MEA 30 °C 8–9; OA 13–14; YES 6–7; CREA No growth; CYAS No growth; DG18 5–6.

CYA 25 °C, 7 d: Colonies moderately deep, slight sulcate; margins entire; mycelium white; texture floccose; sporulation dense; conidia en masse greyish yellow-green (68); soluble pigments absent; exudates absent; reverse buff (45). MEA 25 °C, 7 d: Colonies moderately deep, sulcate; margins entire; mycelium white and primrose (66); texture floccose; sporulation dense; conidia en masse pistachio green (92); soluble pigments absent; exudates absent; reverse ochreous (44). YES 25 °C, 7 d: Colonies moderately deep, plane; margins entire; mycelium white; texture floccose; sporulation moderately dense; conidia en masse pistachio green (92); soluble pigments absent; exudates absent; reverse buff (45). DG18 25 °C, 7 d: Colonies moderately deep, plane; margins entire; mycelium sulphur yellow (15); texture floccose; sporulation sparse; conidia en masse greyish yellow-green (68); soluble pigments absent; exudates absent; reverse sulphur yellow (15). OA 25 °C, 7 d: Colonies moderately deep, plane; margins entire; mycelium white and primrose (66); texture velvety; sporulation dense; conidia en masse yellow green (71); soluble pigments absent; exudates clear droplets; reverse greyish yellow-green (68). CREA 25 °C, 7 d: No growth.

Conidiophores biverticillate, with a minor proportion having subterminal branches; stipes smooth, 70–130 × 3–4 μm, extra branches 10–20 μm; metulae 3–5, divergent, 8.5–11 × 4–4.5 μm; phialides 4–6, acerose, 9–11 × 3–5 μm; conidia smooth, subglobose to fusiform, 2–4.5× 3–4 μm. Ascomata not observed, white sclerotia present on OA after 1 wk.

Talaromyces albisclerotius is characterized by the production of white sclerotia on OA after 1 wk incubation; these sclerotia remain sterile and no ascospores are observed after prolonged incubation up to eight wk. Talaromyces assiutensis and T. trachyspermus could produce white ascomata, but their ascomata mature after weeks and release ascospores (Yilmaz et al. 2014). Phylogenetically, T. albisclerotius clusters with T. diversus and T. brasiliensis, but T. diversus grows faster on MEA, and T. brasiliensis produces rough conidia (Yilmaz et al. 2014; Barbosa et al. 2018).

Latin, albisclerotius, refers to its white sclerotia produced on OA.