Delimitation of central and northern European species of the Phellinus igniarius group (Basidiomycota, Hymenochaetales) based on analysis of ITS and translation elongation factor 1 alpha DNA sequences

Abstract

The Phellinus igniarius group comprises several closely related wood-decaying basidiomycetes with poroid hymenophores that are sometimes difficult to identify on a morphological basis. The delimitation of pileate species belonging to the group was the subject of ITS (internal transcribed spacer of ribosomal DNA) and tefa (translation elongation factor 1 alpha) DNA sequence analyses applied to specimens from central and northern Europe. The results confirmed the distinctiveness of P. alni, P. igniarius, P. lundellii, P. nigricans, P. populicola, P. tremulae, and P. tuberculosus in Europe. The specimens of the previously distinguished species P. cinereus were found to be identical with either P. nigricans or P. alni. Thus, Phellinus cinereus does not follow the species criteria of phylogenetic species recognition. In addition, a recently described species, P. neolundellii, was grouped within the P. alni clade. The ITS and tefa analyses produced a different topology for P. populicola and P. igniarius. P. alni had the largest spectrum of hosts, including woody plants from nine families, and records on Aesculus hippocastanum and Ulmus glabra are reported for the first time. P. igniarius s.s. has been collected not only on Salix spp. as expected but also, though rarely, on Populus nigra, and it has been observed once on Malus domestica. The host specificity of the remaining species resembles previous data. An additional analysis of basidiospore dimensions did not reveal any differences between P. alni and P. igniarius, but both are distinguishable from those of P. nigricans.

Phylogenetic Relationships among Species of Phellinus sensu stricto, Cause of White Trunk Rot of Hardwoods, from Northern North America

“…For all data sets, the model that produced the highest -lnL score was the general time reversible (GTR) substitution model [35]. Sequences generated in this study were combined with data from previous studies [7,9,12,36,57]. Information for these isolates is provided in Table 1.…”

“…Based on several independent studies that utilized the morphological, biological and phylogenetic species concepts, it is clear that Phellinus sensu stricto (s.s.) is composed of a limited number of species that cause a delignifying trunk rot of deciduous hardwoods, with minor exceptions [1][2][3][4][5][6][7][8][9][10][11][12]. Numerous other species previously classified as Phellinus [13] are now members of various segregate genera (e.g., Fomitiporia, Fuscoporia, Inonotus, Onnia, Phellinidium and Porodaedalea, among others) [7][8][9].…”

“…Ironically, it has been hypothesized that P. igniarius s.s. is a European species restricted to Salix [6,9]. However, a broader survey of species incidence by Tomšovský et al [12] demonstrated that while P. igniarius s.s. is most common on Salix, it also occurs on Populus and Malus in Europe and Asia, signifying this species could potentially occur on all members of the Salicaceae and Rosaceae growing in northern temperate regions. An additional Phellinus species found only on Populus, P. populicola, is genetically similar to P. igniarius s.s. and is present throughout northern Europe and Asia [6,12].…”

“…Phylogenetic analyses have vastly improved the ability to discriminate genera and species in Phellinus s.l., yet most studies that include Phellinus s.s. have primarily utilized isolates collected from Europe [6][7][8][9]12], leaving North American researchers to speculate about species distribution and host specificity. The goals of this study were to determine the incidence and host distribution of Phellinus s.s. species using isolates that originated from northern temperate forests in North America.…”

Cryptic species diversity in polypores: the Skeletocutis nivea species complex

“…Antrodia crassa (Spirin et al 2015), Heterobasidion insulare (Chen et al 2014, Dai and Korhonen 2009), Laetiporus sulphureus (Banik et al 2010, Vasaitis et al 2009), Phellinus igniarius (Tomovský et al 2010, Zhou et al 2016) and Porodaedalea pini (Brazee and Lindner 2013). In the above-mentioned cases, the newly discovered species can be, and mostly were, characterised morphologically.…”