A new Sparassis species from Spain described using morphological and molecular data

Abstract

Sparassis miniensis, collected in Pinus pinaster forests in Galicia (northwest Iberian Peninsula) is described as a new species, based on morphological and molecular data. Sparassis miniensis is morphologically distinct from all other species in the genus Sparassis based on scattered flabellae, which are strongly laciniated, azonate, and arise from an orange to rose-purplish base. The sporadic presence of clamp connections is restricted to subhymenial hyphae. Molecular data from LSU-rDNA, ITS and partial gene coding RNA polymerase subunit II (rpb2) suggest a close relationship between the new species S. miniensis and S. brevipes, another European species producing large fruiting bodies but with entire flabellae and no clamp connections.

Introduction

Sparassis species are distributed worldwide, and they have been collected and studied morphologically in Europe for many years (e.g. Hennig, 1952, Kreisel, 1983, Reid, 1958). The phylogenetics of the genus Sparassis were recently studied using materials from eastern Asia, North America, Australia, and to a lesser extent from Europe. A close relationship between Sparassis species and two polypores, Laetiporus sulphureus and Phaeolus schweinitzii, which also produce brown rot, was suggested by sequence data from rDNA (including the ITS region) and the partial gene coding RNA polymerase subunit II (rpb2) (Wang et al. 2004). Using both morphological and molecular data, seven potential Sparassis species have been recognized: S. crispa, S. radicata, S. brevipes (syn. S. laminose, S. nemecii) (Kreisel 1983), S. spathulata (syn. S. herbstii) (Burdsall & Miller 1988), S. cystidiosa, and two undescribed taxa, one from Australia and one from Asia (Desjardin et al., 2004, Wang et al., 2004).

The objectives of the present study are the morphological characterization of a new Sparassis species, S. miniensis, and estimation of its phylogenetic position in the genus Sparassis, extending the data of Desjardin et al. (2004) and Wang et al. (2004). Their studies suggested that the presence of clamp connections, geographic distribution and macromorphology of basidiomata are critical in recognizing Sparassis species. Biogeographic relationships among Sparassis species still remain unclear and data from collections in Europe and adjacent areas are critical for resolving this biogeographic puzzle (Wang et al. 2004). Based on rDNA and rpb2 data, European species of Sparassis are closely related to those from North America, and a sister relationship between North American S. spathulata and European S. brevipes received strong support from the molecular data. However, European materials of Sparassis species were incompletely sampled. For example, material of the European S. simplex, which is potentially synonymous with S. spathulata (Burdsall & Miller 1988), was not available for this study and the study of Wang et al. (2004). In this study, several recent collections from Galicia in the northwest of Spain are described as a new species, S. miniensis.