A comparison between ITS phylogenetic relationships and morphological species recognition within Mycena sect. Calodontes in Northern Europe

Abstract

The members of Mycena sect. Calodontes (Tricholomataceae s.l., Basidiomycota) are characterised by a collybioid aspect and more or less purplish to reddish colours and a distinct raphanoid odour. In Europe, nine species have been recognised though some of these based on somewhat dubious morphological differences. Historically, most were assigned to Mycena pura. However, since Mycena pura displays one of the most striking colour variabilities within European agarics, many attempts have been made to subdivide it into independent entities, and several forms, varieties and species have been split from Mycena pura s.l. based largely on differences in colouration, gross macromorphology or other phenetic traits. We developed a large sample of ITS sequences of all species of sect. Calodontes known from Europe for which vouchers exist. Furthermore, partial LSU data were developed and additional sequences downloaded from GENBANK to assess the relationship of Calodontes with other Mycena spp. We show that most Calodontes form a monophyletic group including a few North and South American collections, but that this cannot be conclusively shown when an additional North American sequence is added. For all other species than M. pura and M. diosma, we found morphological species recognition to be in agreement with the ITS data. Several significantly different clades can be recognised within the M. pura morphospecies, none of which can be linked to the observed (and described by proxy) colour varieties/forms. Indications of a possible environmental basis of the colour differentiation in the M. pura morphospecies are discussed.

The unbearable lightness of sequenced-based identification

“…However, when using a BLAST which is limited to type sequences, the number of listed Mycena sequences in BLAST results drops down to four species, none from Europe. In this study we have revealed 'hidden' type sequences for at least 15 (but possibly 20) European Mycena species among existing GenBank deposits by Osmundson et al (2013) and Harder et al (2010Harder et al ( , 2012Harder et al ( , 2013, and the potential for the recognition of an additional number of reference sequences among the remainder of the 130 Mycena sequences obtained from the Robich collection in the herbarium of Venice (Osmundson et al 2013). 2.…”

“…We thus aligned our ITS sequences with representative sequences from GenBank for sect. Purae benefitting from recently published phylogenetic studies (Harder et al 2010(Harder et al , 2013 and the authoritative but apparently problematic Mycena sequences from the Venice barcode project (Osmundson et al 2013). Our phylogenetic analyses (Fig.…”

In vitro evidence of root colonization suggests ecological versatility in the genus Mycena

“…Betula pendula was used in the present study and it may be possible that the observed interactions are between incompatible symbionts. While further research is necessary to resolve this question, it must be noted that the M. pura morphospecies has well‐known generalist properties for substrate affinity (Harder et al , 2010, 2013). The M .…”

Mycenaspecies can be opportunist-generalist plant root invaders

“…4 However, the M. pura from Svalbard and Vettakollen (in mainland Norway) and a M. rosea1 from Gribskov had isotopic signatures closer to the expected profiles for saprotrophs. The members of the Mycena section Calodontes are notably hard to grow in culture which has previously led to speculations about their nutrition (Perreau et al ., 1992; Boisselier-Dubayle et al ., 1996; Harder et al ., 2010; Harder et al ., 2012). However, it must be noted that Mycena pura was rarely found in the root samples and only constituted a significant (>10%) fraction of the root community in one single B. vivipara individual (Fig.…”