Mycena rosella CBHHK067 v1.0
Mycena rosella
© A. Aronsen VESTFOLD, Re, Langevann 7 Oct. 2006

The genome of Mycena rosella was sequenced as part of the overarching JGI 1000 Fungal Genomes project "Deep Sequencing of Ecologically-relevant Dikarya" (CSP 1974) -- and more specifically, as a part of the Mycenaceae sequencing project. This project will examine members of the Mycena genus with respect to evaluate the genomic basis of their different nutritional modes.

The Pink Bonnet, Mycena rosella

Mycena rosella is a member of the Luculentae section of the Mycena family, and closely related to Mycena aurantiomarginata (Maas Geesteranus 1988). This culture was collected in Norway (in Telemarken, September 2015), and the species has been widely reported from coniferous forests all over Europe and North America (Maas Geesteranus 1988, Miller and Miller 2006, Arne Aronsen 2017). Its bright roseate colours and its dark lamellar edge (due to its coloured cheilocystidia) makes it hard to overlook in the forest bottom, and very easy to identify also for the untrained.

Description

Pileus 5-20 mm across, parabolical to convex, finally almost plane with a small umbo, sulcate, translucent-striate, glabrous, without or with a shallow umbo or occasionally centrally somewhat depressed, bright pink, salmon pink to brownish pink, usually darker at the centre, brownish red, sienna coloured. Lamellae 15-18 reaching the stipe, ascending to subhorizontal, ventricose, broadly adnate, somewhat decurrent, dingy pink or pale pink, minutely punctate with reddish dots (pleurocystidia), the edge bright violet red or brownish red. Odeur and taste indistinctive. Stipe 20-50 x 0.5-2 mm, hollow, terete, straight, often curved below, pruinose, glabrescent, in young specimens dark brown at the apex and paler brown below, then reddish brown, becoming pale pink, yellowish pink to pale pink brown, the base densely covered with long, coarse, flexuous, yellowish to whitish fibrils.

Basidia 25-33 x 6.5-9 m, clavate, 4-spored. Spores 7.5-10 x 4-5 µm, Q = 1.6-2.3; Qav ~ 1.9, pip-shaped, smooth, amyloid. Cheilocystidia 25-80 x 4.5-18 µm, forming a sterile band, clavate to fusiform or more rarely somewhat irreularly shaped, with red contents, smooth or covered with few to fairly numerous, unevenly spaced, simple or more rarely furcate, cylindrical to variously inflated, straight to curved excrescences 1.5-10 x 1.5-5.5 µm. Pleurocystidia fusiform, smooth, with red contents. Lamellar trama dextrinoid, brownish vinescent in Melzer's reagent. Hyphae of the pileipellis 2.5-10 µm wide, sparsely to densely covered with warts and cylindrical excrescences 1-2.5 x 1-2 µm and partly covered with variously branched side-branches, tending to be somewhat gelatinized. Hyphae of the cortical layer of the stipe 2-4.5 µm wide, smooth to sparsely covered with cylindrical excrescences; the terminal cells inflated 5.5-12.5 µm wide, covered with warts or cylindrical excrescences. Clamp connections abundant at all tissues. See also: http://www.mycena.no/rosella.htm.

Its growing season is autumn, and it it found exclusively on coniferous needles, where it is common throughout its distribution range, and indeed appear to be a quantitatively important needle litter decayer in boreal forests (Senn-Irlet and Bieri 1999). As a saprotroph with a relatively narrow niche, it falls towards the comparatively (but not highly) specialised end on a continuum of generalists vs. specialists in the genus, and the genome of this species will yield important information about the evolution of this niche specialisation between specialists and generalists. Furthermore, M. rosella is one among the few mushroom species where transcontinental fertility between strains from Europe and North America have been documented (Petersen and McCleneghan 1997). Thus, we also hope that its genome will provide clues to the evolution of the elaborate basidiomycete mating system with respect to the genetic basis for fertility barriers and reinforcement.

This genome was derived from diploid pure culture on MEA agar with ampicilin and benomyl and should be free of xenobiotic contaminations.

Researchers who wish to publish analyses using data from unpublished Mycena genomes are respectfully required to contact the PI and JGI to avoid potential conflicts on data use and coordinate other publications with the Mycena master paper(s).

References

Aronsen, A. (2017): A key to the Mycenas of Northern Europe. http://www.mycena.no/rosella.htm

Maas Geesteranus, R. A. (1988): Conspectus of the Mycenas of the Northern Hemisphere. Proc. Kon. Ned. Akad. v. Wetensch. (Ser. C).

Miller HR, Miller OK (2006): North American Mushrooms: a Field Guide to Edible and Inedible Fungi. Guilford, Conn: Falcon Guide.

Petersen, R.H. and McCleneghan, S.C. (1997): Reports on long-distance sexual compatibility in Agaricales. Nordic Journal of Botany 17: 419-432.

Senn-Irlet, B. and Bieri, G. (1999): Sporocarp succession of soil-inhabiting macrofungi in an autochthonous subalpine Norway spruce forest of Switzerland. Forest Ecology and Management, 124(2), 169-175.