Penicillium steckii K.W. Zaleski, Bull. Int. Acad. Polon. Sci., Ser. B., Sci. Nat.1927: 469 (1927).

MycoBank number: MB 278769; Index Fungorum number: IF 278769; Facesoffungi number: FoF 11348; Fig. 1

Holotype – IMI 40583

Culture characteristics – Colonies growing after 5 days at 25 ± 2 °C on following agar media: CYA colonies slow-growing, umbonate, cottony, 2–4 mm in diam.; margins irregular; sporulation white; exudates colourless; soluble pigments absent; reverse wrinkled, cream. MEA colonies slow-growing, radially sulcate, velutinous, umbonate, powdery, mycelia pale white(1A1), 19 mm in diam.; margins regular; sporulation white, dark green (27F6) between mycelia and sporulation; exudate absent; soluble pigment absent; reverse wrinkled, mycelia ivory/natural/platinum blonde sand (4B3), sporulation white. CYAS colonies slow-growing, floccose, umbonate, cottony, mycelia pastel green (25A4), 9 mm in diam.; margin irregular; sporulation greenish-white (25A2); exudate absent; soluble pigment absent; reverse wrinkled, mycelia dark green (30F8), sporulation pale orange (6A3). OA colonies medium growing, flat, granular, powdery, mycelium grey (29E4), 12 mm in diam.; margins regular; sporulation white, greyish green (29E4) in between mycelia and sporulation; exudates colourless; soluble pigment absent; reverse mycelia greyish green, white sporulation (29A1). CZ colonies slow-growing, flat, granular, mycelium white (1A1), 13 mm in diam.; margins irregular; exudate absent; soluble pigment absent; reverse white (1A1). DG18 colonies slow-growing, flat, cottony, suppressed, mycelium white (1A1), 7–9 mm in diam.; margin regular; exudates absent; soluble pigments absent; reverse white (1A1). YES colonies medium growing, floccose, radially sulcate, umbonate, cottony, mycelium dull green (29E3), 10–11 mm in diam.; margins irregular; sporulation white and greenish-grey (27C2) in mycelia and sporulation; exudate absent; soluble pigment absent; reverse wrinkled, mycelia dull green (27E4) to white, sporulation pale yellow. CREA colonies slow-growing, flat, powdery, mycelia greenish-white (26A2), pastel green (26B4) towards mycelia, 8–10 mm in diam.; margin irregular; sporulation white; acid production present, soluble pigment, pale yellow (3A3); reverse wrinkled, radiate, white sporulation (1A1), mycelia and sporulation, maize yellow (4A6) and olive-brown (4D4).

Micromorphology – Conidiophores arising from mycelium mat, predominant symmetrically biverticillate, terverticillate structures abundantly produced in fresh isolates. Stipes smooth, width 2–3 µm. Metulae in whorls of 2–4, 12–16×2–2.7 μm. Phialides ampulliform, 7.5–10×2–2.5 μm. Conidia 2–2.5×1.8–2.5 μm, smooth-walled, globose to subglobose.

Material examined – India, Maharashtra, Pune (18° 31′ 47″ N, 73° 48′ 59″ E), from soil, 12 September 2018, K.C. Rajeshkumar, NFCCI 5065. Substrates and distribution: Bermuda, Egypt, Indonesia, Japan, Netherlands, Panama, Slovenia, and Venezuela

GenBank numbers – ITS: OK345037, BenA: OL652649, CaM: OM948804.

Notes – The concatenated phylogenetic analyses of ITS, BenA, CaM, and rpb2 genes reveals that our isolate (NFCCI 5065) clustered with the type stain of Penicillium steckii (CBS 26055) with ML/BI=100%/1.00 statistical support. Further, both strains share the same characters such as bi-to terverticillate conidiophore branching with globose to subglobose conidia with a smooth ornamentation. Hence, we identified our collection (NFCCI 5065) as P. steckii based on morphology and phylogenetic analyses and this is the first report from India.

Figure 1 – Penicillium steckii (NFCCI 5065). a, b Colonies after 5 days at 25±2 °C on CYA and MEA obverse and reverse. c–h CREA, CYAS, CZA, DG18, OA, YES. i, j Biverticillate conidiophore. k Conidia. Scale bar: i–k=10 μm