Penicillium subrubescens Houbraken, Mansouri, Samson & Frisvad, Antonie van Leeuwenhoek 103(6): 1354 (2013).
MycoBank number: MB 801306; Index Fungorum number: IF 801306; Facesoffungi number: FoF 11349; Fig. 1
Holotype – CBS H-21029
Culture characteristics – Colonies growing after 5 days at 25±2 °C on following agar media: CYA colonies medium growing, floccose, sporulation turquoise white (24A2), 18 mm in diam.; margins irregular; exudates colourless; soluble pigments absent; reverse wrinkled, butter yellow (4A5). MEA colonies medium growing, radially sulcate, velutinous, sporulation pale yellow (1A3), 22 mm in diam.; margins irregular; exudate absent; soluble pigment absent; reverse sulcate, butter yellow (4A5). CYAS colonies slowgrowing, floccose, mycelium white (1A1), 9 mm in diam.; margin irregular; exudate absent; soluble pigment absent; reverse greyish yellow (4B6). OA colonies medium growing, flat, granular, mycelium white, 6 mm in diam.; margins irregular; sporulation yellowish-white (1A2); exudates colourless; soluble pigment absent; reverse yellowish-white (1A2). 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, mycelium white (1A1), 6 mm in diam.; margin irregular; exudate absent; soluble pigment absent; reverse white (1A1). YES colonies medium growing, floccose, mycelium white (1A1), 21 mm in diam.; margins irregular; sporulation orange white (5A2); exudate absent; soluble pigment absent; reverse wrinkled, sulcate, butter yellow (4A5). CREA 25 °C, 5 day, in darkness: Colonies slow-growing, flat 10 mm in diam.; margin irregular; acid production absent; sporulation yellowish-white (3A2); reverse white (1A1).
Micromorphology – Conidiophores predominantly biverticillate, often with one or more additional branches that also have symmetrically biverticillate structures; stipes coarsely roughened, 150–400 × 2.5–4 μm; metulae in verticils of 3 to 6, walls roughened, both equal and unequal in length, 10–15 (− 20) × 2.0– 3.5 μm; phialides ampulliform with distinct neck, with walls occasionally roughened, 7.0–9.5 × 2.0–3.5 μm; conidia subglobose to broadly ellipsoidal, smooth or finely roughened, 2.5–3.0×2.0–2.7 μm.
Material examined – India, Uttarakhand, Almora (29° 35′ 15″ N, 79° 35′ 46″ E), from soil, 27 February 2019, K.C. Rajeshkumar, NFCCI 5063.
Substrates and distribution – Soil of an artichoke field in Jerusalem, soil of Helianthus tuberosus field in Canada, Finland, Tanzania, and USA
GenBank numbers – ITS: OK345037, BenA: OL652649, CaM: OM948804, rpb2: OL652655.
Notes – The concatenated phylogenetic analyses of ITS, BenA, CaM, and rpb2 genes placed our isolate (NFCCI 5063) along with the type stain of Penicillium subrubescens (CBS H-21029). Further, both strains have identical morphological characters such as, predominant symmetrically biverticillate conidiophore, globose to ellipsoidal conidia and smooth ornamentation. Therefore, we identified our isolate as P. subrubescens and this is the first record of P. subrubescens from India (Fig. 2).
Figure 1 – Penicillium subrubescens (NFCCI 5063). a, b Colonies after 5 days at 25±2 °C on CYA and MEA surface and reverse view. c–h CREA, CYAS, CZA, DG18, OA, YES. i monoverticillate conidiophore. j–k biverticillate conidiophore. l Conidia. Scale bar: i–l=10 μm
Figure 2 – Phylogeny inferred using combined dataset of ITS, BenA, CaM, and rpb2 of Penicillium subgenus Aspergilloides in RAxML. The matrix had 1447 distinct alignment patterns with 15.76% undetermined characters and gaps. Estimated base frequencies were as follows; A=0.224185, C=0.284056, G=0.262355, T=0.229404; substitution rates AC=1.095739, AG=3.139871, AT=1.227232, CG=0.748372, CT=4.755400, GT=1.0; gamma distribution shape parameter α=0.299261. Bootstrap support for ML equal to or greater than 80%, Bayesian posterior probabilities (BI) equal to or greater than 0.9 are shown at the nodes. The tree is rooted to Aspergillus glaucus (NRRL 116). The newly generated sequences are indicated in blue bold