Considerations and consequences of allowing DNA sequence data as types of fungal taxa.

Nomenclatural type definitions are one of the most important concepts in biological nomenclature. Being physical objects that can be re-studied by other researchers, types permanently link taxonomy (an artificial agreement to classify biological diversity) with nomenclature (an artificial agreement to name biological diversity). Two proposals to amend the International Code of Nomenclature for algae, fungi, and plants (ICN), allowing DNA sequences alone (of any region and extent) to serve as types of taxon names for voucherless fungi (mainly putative taxa from environmental DNA sequences), have been submitted to be voted on at the 11th International Mycological Congress (Puerto Rico, July 2018). We consider various genetic processes affecting the distribution of alleles among taxa and find that alleles may not consistently and uniquely represent the species within which they are contained. Should the proposals be accepted, the meaning of nomenclatural types would change in a fundamental way from physical objects as sources of data to the data themselves. Such changes are conducive to irreproducible science, the potential typification on artefactual data, and massive creation of names with low information content, ultimately causing nomenclatural instability and unnecessary work for future researchers that would stall future explorations of fungal diversity. We conclude that the acceptance of DNA sequences alone as types of names of taxa, under the terms used in the current proposals, is unnecessary and would not solve the problem of naming putative taxa known only from DNA sequences in a scientifically defensible way. As an alternative, we highlight the use of formulas for naming putative taxa (candidate taxa) that do not require any modification of the ICN.

Typification of Octaviania rubescens (Paxillineae, Boletales) and phylogenetic hypotheses for genus Alpova.

There are no usable herbarium specimens for the type of Alpova rubescens; therefore a lectotype and an epitype are designated hereby to preserve current usage of the name. As lectotype the Vittadini's Fig. XII E/Tab. IV (from Monographia Tubera-cearum) was selected. The epitype chosen for A. rubescens is a recent large collection from Liguria (Italy). Furthermore to investigate the phylogenetic position of A. rubescens among Alpova spp. comparative 28S-rDNA gene sequence analyses were conducted. The new combination Rhizopogon alexsmithii (Trappe) Vizzini & Zotti is proposed.

Albatrellus citrinus sp. nov., connected to Picea abies on lime rich soils.

Field observations indicated that a morphotype of Albatrellus subrubescens seemed connected to Picea abies and lime rich soils, while the original morphotype seemed connected with Pinus sylvestris and indifferent to lime. We conducted a molecular study (ITS sequencing of 22 Albatrellus specimens) to test the hypothesis that we in fact had discovered a new species. Our results confirmed the hypothesis, i.e. the Picea taxon (604 bp ITS) had little intraspecific variation in spite of 1600 km distance between samples, but compared with the Pinus taxon (598 bp ITS) the sequence difference was constantly 5.6% regardless of close distance (75 km). We describe the new species A. citrinus, which apart from ecology and ITS sequence, is different from A. subrubescens by a distinct yellowing with age, lack of dark spots of the cap, a mild taste and somewhat narrower spores. A. citrinus seems to be more related to A. ovinus than to A. subrubescens, and A. syringae may not even be a true Albatrellus.