Multilocus phylogenetic analyses reveal unexpected abundant diversity and significant disjunct distribution pattern of the Hedgehog Mushrooms (Hydnum L.)

Abstract

Hydnum is a fungal genus proposed by Linnaeus in the early time of modern taxonomy. It contains several ectomycorrhizal species which are commonly consumed worldwide. However, Hydnum is one of the most understudied fungal genera, especially from a molecular phylogenetic view. In this study, we extensively gathered specimens of Hydnum from Asia, Europe, America and Australasia, and analyzed them by using sequences of four gene fragments (ITS, nrLSU, tef1α and rpb1). Our phylogenetic analyses recognized at least 31 phylogenetic species within Hydnum, 15 of which were reported for the first time. Most Australasian species were recognized as strongly divergent old relics, but recent migration between Australasia and the Northern Hemisphere was also detected. Within the Northern Hemisphere, frequent historical biota exchanges between the Old World and the New World via both the North Atlantic Land Bridge and the Bering Land Bridge could be elucidated. Our study also revealed that most Hydnum species found in subalpine areas of the Hengduan Mountains in southwestern China occur in northeastern/northern China and Europe, indicating that the composition of the mycobiota in the Hengduan Mountains reigion is more complicated than what we have known before.

Phylogeny, biogeography and taxonomic re-assessment of Multifurca (Russulaceae, Russulales) using three-locus data

“…Pisolithus and some species pairs of Hysterangiales for the first hypothesis, Solioccasus and Hydnum p.p. for the second, and Cyttaria and Tuberaceae for both the first and third) [ 65 – 69 ]. Our analysis using a more ancient calibration point (500–560 Ma for the stem base age of Ascomycota) estimated the origin of Multifurca to be centered at the early Paleocene, well after the breakup of Gondwana.…”

Six new species and reports of Hydnum (Cantharellales) from eastern North America

“…Initial phylogenetic studies of European Hydnum revealed higher than expected taxonomic diversity in the genus, with thirteen molecularly recognized clades masquerading under four morphologically-defined species names (Grebenc et al 2009), which have since been described as new species (Olariaga et al 2012, Vizzini et al 2013, Niskanen et al 2018). Following a global survey of diversity in the genus which estimated 31 species worldwide based on molecular phylogenetic analysis (Feng et al 2016), additional taxonomic work in Europe and North America has raised the global species count to 34 (Buyck et al 2017, Niskanen et al 2018), which is estimated to be less than half of the total number of Hydnum species (Niskanen et al 2018). This previously overlooked diversity may be due to morphological stasis in evolution of basidiome morphology and lack of attention to regional characterization of the Hydnum flora in locations outside Europe.…”

“…Ecologically, Hydnum form ECM associations with a variety of vascular plant species including members of Pinaceae (Agerer et. al 1996), Myrtaceae (McNabb 1971), Fagales (McNabb 1971, Feng et. al 2016, Niskanen et al 2018), Salicaceae (Niskanen et al 2018), Malvaceae (Niskanen et al 2018), and Dipterocarpaceae (Lee et al 2002).…”

“…al 2016, Niskanen et al 2018), Salicaceae (Niskanen et al 2018), Malvaceae (Niskanen et al 2018), and Dipterocarpaceae (Lee et al 2002). The genus is distributed mostly in temperate areas, with a few reports from tropical and subtropical forests in southeast Asia (Lee et al 2002, Feng et al 2016) and the neotropics (Garibay-Orijel et al 2006, Sarmiento and Fontecha 2013, Feng et al 2016, Niskanen et al 2018).…”

“…Previous analysis of global Hydnum diversity revealed the presence of six distinct clades of Hydnum in eastern North America, only one of which also occurs on another continent (Feng et al 2016). Currently, five species have been described from eastern North America: H.albidum Peck, H.albomagnum Banker, H.aerostatisporum Buyck, D.P.…”