Penicillium heteromorphum H.Z. Kong and Z.T. Qi. Mycosystema 1:107. 1988.

Torres-Garcia, Daniel, Gene, Josepa & Garcia, Dania, 2022, New and interesting species of Penicillium (Eurotiomycetes, Aspergillaceae) in freshwater sediments from Spain, MycoKeys 86, pp. 103-145 : 103

Penicillium heteromorphum H.Z. Kong and Z.T. Qi. Mycosystema 1:107. 1988.

Figure 11

Subgeneric classification.

Subgenus Penicillium Aspergilloides , Penicillium section Exilicaulis . series Penicillium Restricta .

Description.

Mycelium superficial and immersed, composed of septate, smooth-walled, hyaline hyphae, 1.5-3 μm wide. Conidiophores monoverticillate, occasionally irregularly branched; stipes smooth-walled, thin, 6-47.5 × 1.5-2 μm; phialides 2-3 per stipe, ampulliform, 3-7 × 1.5-2.5 μm; conidia roughened, globose to subglobose, 2.5-3 × 2.5-3 μm, occasionally conidia up to 5 μm were observed.

Culture characteristics (7 d at 25 °C).

Colonies on CYA, 19-20 mm diam., slightly raised at center, velvety, radially sulcate, yellowish gray (4B2) at center and white (1A1) at periphery, margins slightly undulate, sporulation absent; reverse pale yellow (4A3); soluble pigment absent. On MEA, 27-28 mm diam., slightly raised at center, velvety, white (1A1) at center, ash blond (3C3) towards periphery, margins entire, sporulation absent; reverse champagne colored (4A4) at center, pastel yellow (3A4) towards periphery; soluble pigment absent. On YES, 22-21 mm diam., slightly raised at center, velvety, radially sulcate, yellowish gray (4B2) and Sahara colored (6C5), margins entire, sporulation absent; reverse grayish orange (5B5) at center and champagne colored (4B4) towards periphery; soluble pigment absent. On OA, 23-24 mm diam., slightly elevated at center, floccose, greenish gray (28B2) at center and beige (4C3) towards periphery, margins fimbriate, sporulation abundant, conidial masses dull green (29E3); reverse beige (4C3); soluble pigment absent. On DG18, 14-15 mm diam., slightly raised at center, velvety, yellowish white (1A2) at center and white (1A1) towards periphery, margins regular, sporulation absent; reverse wine yellow (3B3) at center and yellowish white (3A2) towards periphery; soluble pigment absent. On CREA reaching 17-19 mm diam., slightly raised at center, floccose, white (1A1) at center and lemon yellow (3B8) towards periphery, margins fimbriate, sporulation absent; reverse lemon yellow (3B8); soluble pigment absent and acid production moderate. Colonies on Czapek’s agar reaching 13-14 mm diam., flattened, floccose, white (1A1) at center to ash gray (1B2) towards periphery, margins entire, sporulation abundant, conidial masses dull green (29D3); reverse ash gray (1B2); soluble pigment absent.

Colony diameter on CYA after 7d (mm).

5 °C no growth, 15 °C 9-11, 20 °C 12-13, 30 °C 23-24, 35 °C 16-19, 37 °C 4-7, 40 °C no growth.

Specimen examined.

Spain, Catalonia, Berguedà, Gósol, from stream sediments, Nov. 2019, J. Gené (CBS 148239, FMR 18043).

Distribution.

China and Spain.

Notes.

Penicillium heteromorphum was first described from a soil sample collected in Shennongjia, China. FMR 18043 is thus the second isolate of this species. The protologue of P. heteromorphum , which was based on CYA and Czapek’s agar, noted that it does not grow at 37 °C, has strictly monoverticillate conidiophores with stipes up to 60 μm long, and produce conidia that are globose to subglobose, smooth or nearly, which show two well-differentiated measures on Czapek’s agar (ones of 2-2.5 (-3) μm diam, and the largest of 4-10 μm) ( Kong and Qi 1988). By contrast, despite the high sequence similarity to the ex-type strain, our isolate differs phenotypically in its ability to grow at 37 °C, and in the production of shorter conidiophores and rough-walled conidia in all media studied; some larger conidia (up to 5 μm diam.) were only observed on Czapek’s agar. Nevertheless, features we observed in the sediment isolate P. heteromorphum match those of the species of series Restricta , which briefly consisted in growing restricted to moderately fast, producing generally short monoverticillate conidiophores with smooth stipes, globose to subglobose or (broadly) ellipsoidal, smooth or roughened conidia and they commonly grow at 37 °C ( Houbraken et al. 2020). Based on the production of two types of conidia, Kong and Qi (1988) compared P. heteromorphum with P. dimorphosporum . However, although both species belongs in section Exilicaulis , the current taxonomy of the genus places P. dimorphosporum in the genetically distant series Erubescentia (Visage et al. 2016b, Houbraken et al. 2020).

Figures

Figure 11. Morphological characters of Penicillium heteromorphum (FMR 18043). A colonies from left to right (top row) CYA, MEA, YES, and OA; (bottom row) CYA reverse, MEA reverse, DG 18, and CREA B, C, F conidiophores on OA. D, E conidiophores on Czapek's Agar G-H conidia. Scale Bars: 25 μm (B), 10 μm (C-H).