Research Article |
Corresponding author: Alfredo Vizzini ( alfredo.vizzini@unito.it ) Academic editor: Maria-Alice Neves
© 2018 Alfredo Vizzini, Renato Jonny Ferrari, Enrico Ercole, Alessandro Fellin.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Vizzini A, Ferrari RJ, Ercole E, Fellin A (2018) A new species of Rhodocybe sect. Rufobrunnea (Entolomataceae, Agaricales) from Italy. MycoKeys 36: 21-33. https://doi.org/10.3897/mycokeys.36.27094
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Rhodocybe fumanellii is described from Italy as a new species based both on morphological and molecular nrITS/nrLSU data. It belongs in sect. Rufobrunnea and is characterised by massive tricholomatoid basidiomata with reddish-brown tinges, adnate and crowded lamellae, an enlarged stipe base with long rhizomorphs, long sinuose slender cheilocystidia, ellipsoid basidiospores and the presence of caulocystidia. Drawings of the main micromorphological features as well as a colour photograph of fresh basidiomata in situ are provided and its morphological relationships with allied species are discussed.
Agaricomycetes , Basidiomycota , Molecular markers, Phylogeny, Taxonomy
Recently,
Within Rhodocybe s.s., section Rufobrunnea, typified by R. roseiavellanea (Murrill) Singer, is characterised by a reddish-beige, salmon pink, pinkish-brown or ochre pileus, adnate or decurrent lamellae and absence of pseudocystidia (
Macroscopic description was based from detailed field notes on fresh basidiomata. Colour terms in capital letters (e.g. Pompeian Red, Plate XIII) are those of
Micromorphologic features were observed on fresh and dried material; sections were rehydrated in distilled water or 3% NH4OH and then mounted in anionic Congo red as universal dye, lactic Cotton blue to test for cyanophily and Melzer’s reagent to determine amyloidity, separately.
All microscopic measurements were carried out with a 1000× oil immersion objective using the Optika Vision Lite 2.1 software. Basidiospores were measured from hymenophores of mature basidiomes and dimensions (hilar appendix excluded) are given as: (minimum–) average minus standard deviation – average – average plus standard deviation (–maximum) of length × (minimum–) average minus standard deviation – average – average plus standard deviation (–maximum) of width, Q = (minimum–) average minus standard deviation – average – average plus standard deviation (–maximum) of ratio length/width. Spore statistics were produced with R version 3.4.4 (
Total DNA was extracted from a dry basidioma (MCVE 29550) by blending a portion of it (about 20 mg) with the aid of a micropestle in 600 μl CTAB buffer (CTAB 2%, NaCl 1.4 M, EDTA pH 8.0 20 mM, Tris-HCl pH 8.0 100 mM). The resulting mixture was incubated for 15 min at 65°C. A similar volume of chloroform:isoamyl alcohol (24:1) was added and carefully mixed with the samples until their emulsion. It was then centrifuged for 10 min at 13,000 g, and the DNA in the supernatant was precipitated with a volume of isopropanol. After a new centrifugation of 15 min at the same speed, the pellet was washed in cold ethanol 70%, centrifuged again for 2 min and dried. It was finally re-suspended in 200 μl ddH2O. PCR amplification was performed with the primers ITS1F and ITS4 (
Sequences obtained in this study were compared to those available in the GenBank (http://www.ncbi.nlm.nih.gov/) and UNITE (http://unite.ut.ee/) databases by using the Blastn algorithm (
Phylogenetic hypotheses were constructed with Bayesian inference (BI) and Maximum Likelihood (ML) criteria. The BI was performed with MrBayes 3.2.6 (
ML estimation was performed through RAxML 7.3.2 (
The nrITS data matrix comprised 64 sequences (1 from the newly sequenced collection, 54 from GenBank and 9 from UNITE). The nrLSU data matrix comprised 40 sequences (1 from the newly sequenced collection and 39 from GenBank). As the Bayesian and Maximum Likelihood analyses of the nrITS sequences are conflicting with each other regarding the precise position of our species, it was decided to show them both (Figs
Italy. Veneto, Venezia, Chioggia, Riserva Naturale Integrale Bosco Nordio, 45°7'19.563"N, 12°15'38.046"E, 4 m a.s.l., mixed broadleaved forest with Fraxinus ornus and Quercus ilex, on consolidated dunes, 10 November 2017, Renato Jonny Ferrari & Enrico Bizio (MCVE 29550).
dedicated to Ezio Fumanelli, Italian mycologist, naturalist and photographer.
Habit tricholomatoid (Fig.
Basidiospores (5.3–)5.68–6.26–6.83(–7.3) × (3.5–)3.93–4.26–4.58(–5.1) µm (n = 40), Q = (1.22–)1.34–1.47–1.60(–1.78), ellipsoid, colourless under the light microscope, finely warty, pustulate, with a wavy profile (angular in polar view with 8–12 facets), walls cyanophilic, inamyloid (Fig.
In small groups (gregarious), in the litter of broadleaved trees on sandy soil. So far, known only from the type locality.
Section Rufobrunnea is a character-poor taxon with many species macroscopically very similar (cryptic species) and differing only in very subtle features (e.g. habit, basidioma colour, type of lamellae insertion, odour, taste, presence/absence of rhizomorphs) (
Rhodocybe fumanellii has proved to be an independent and distinct species within this section based on molecular analyses (Figs
The phylogenetically closest species to R. fumanellii are the recently described R. matesina and R. asanii. Rhodocybe matesina from Italy differs in a collybioid and slender habit (stipe up to 9 mm broad), thin context, a strongly hygrophanous pileus without reddish tinges, a smell similar to Hygrophorus penarioides Jacobsson & E. Larss., bitter and astringent taste, absence of rhizomorphs and an olive-green reaction on the pileus surface with KOH; microscopically R. matesina is distinguished due to shorter cheilocystidia (16.5–23 × 3–6.5 μm), the absence of caulocystidia and the presence in the pileipellis of rare pseudoclamps (
Hereafter, distinctive features of the species in the section Rufobrunnea that somehow morphologically resemble R. fumanellii, are provided. Rhodocybe lateritia T.J. Baroni & G.M. Gates described from Tasmania, is circumscribed by a burnt sienna or reddish-brown cup-shaped, up to 120 mm broad pileus, large, 5.5–11 × 4.5–7.5 μm basidiospores and ascending, cystidioid elements (pileocystidia) in the pileipellis (
We want to thank Enrico Bizio and Gabriele Cacialli for their helpful suggestions and collaboration and the Bresadola Mycological Association (AMB) of Brunico (BZ) for its support.