Global delimitation of Cyanoboletus, Cacaoporus and Cupreoboletus (Basidiomycota: Boletaceae)
This investigation aimed at compiling all phylogenetic lineages within and around genus Cyanoboletus. The evolutionary inference obtained from the nuclear rDNA internal transcribed spacer region (ITS) suggests excluding part of the species currently classified in Cyanoboletus, leaving only the species that develop a strong staining reaction to touch and to air exposure of the context. The excluded lineages are the monotypic Cupreoboletus genus and a few species that do not develop such reaction, forming a clade together with genera Cacaoporus and Acyanoboletus, thus broadening the concept of Cacaoporus to encompass all of them. The emerging 3C perspective of Cupreoboletus, Cacaoporus and Cyanoboletus offers a remarkably consistent morphological diagnosis, overcoming the problems of a too broad concept for Cyanoboletus. Boletus neotropicus, B. novae-zelandiae and B. sensibilis belong respectively in Cyanoboletus, Cacaoporus and Lanmaoa, and lineages that probably represent undescribed species are indicated: at least four in Cacaoporus and at least five in Cyanoboletus. Diagnostic tables and dichotomic keys are presented by geographic region. The present work also includes a study of the phylogenetic position of Neoboletus flavosanguineus, a species once classified in Cyanoboletus. The complexity of assigning species epithets in some lineages is addressed, namely for the boundaries between Cacaoporus instabilis and Ca. fagaceophilus as well as the diversity under the names Cyanoboletus sinopulverulentus and Cy. pulverulentus. The overall picture of evolutionary lineages sets a framework for the choice of reference data that can provide, in future phylogenetic studies that involve the 3C, a balanced and efficient coverage. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=175 SRC="FIGDIR/small/724631v2_ufig1.gif" ALT="Figure 1"> View larger version (24K): org.highwire.dtl.DTLVardef@514af4org.highwire.dtl.DTLVardef@10ffc36org.highwire.dtl.DTLVardef@775871org.highwire.dtl.DTLVardef@14f7985_HPS_FORMAT_FIGEXP M_FIG C_FIG