sdu faculty of forestry journal special edition 2009 - Orman Fakültesi

SDÜ ORMAN FAKÜLTESİ DERGİSİ
In the ITS phylogram, the third clade is composed of P. laricis specimens from
European part of Russia, Kazakhstan and the Russian Far East, Fennoscandia, and
the Central European mountains (Alps, High Tatras, Bohemian Forest). However,
this group is not consistent in both analyses. In the tefa phylogram, five sequences
from the Czech Republic, Norway, Sweden, and Kazakhstan are excluded from this
group due to the presence of unique nucleotide substitutions at positions 166 and
408 in the alignment. Nevertheless, this distant clade is poorly supported.
4. DISCUSSION
The topologies of the two gene regions (ITS, tefa) delimiting Porodaedalea
species are inconcordant, so they do not follow phylogenetic species recognition
(according to Taylor et al., 2000). Nevertheless, the phylogram topologies of these
two regions have been found to be incongruent in other studies (Kauserud et al.,
2007; Ota and Hattori, 2008). The most surprising result in our study is the division
of the homogeneous P. laricis ITS group into two groups in the tefa dataset.
However, the PP and BP values of the P. laricis B group in the tefa phylogram are
low. Therefore, we suggest that the name P. laricis is adopted for all specimens
included in the P. laricis ITS group that were originally identified as P.
chrysoloma. Almost all sequenced specimens from Fennoscandia that were
identified as Phellinus chrysoloma are unrelated to the neotype of that species and
most likely belong to P. laricis instead. Our results resemble those of Černý (1985,
1989), who placed these Fennoscandian specimens growing on Picea in Phellinus
vorax, an incorrectly published name synonymous with Phellinus laricis (Černý,
1985). In any case, the distribution of genuine P. chrysoloma in North
Fennoscandia is questionable. The species occurs without doubt in southern
Sweden and Finland (Larsen and Stenlid 1999; Fischer 2000), but the northern
limit of its distribution is unclear.
The occurrence and host affinity of Porodaedalea is worth a detailed
discussion. Niemelä et al. (2005) assumed strict host specificity of Porodaedalea
species, and therefore they set the westernmost limits of P. laricis in accordance
with the natural occurrence of Larix sibirica in Russia. Although Fischer (2000)
examined a specimen growing on artificially planted Larix from Finland, it was
reported to be an introduced fungus due to the non-indigenous state of its host.
According to our results, P. laricis is widely distributed in Fennoscandia, using
spruce as its host.
In Central Europe, the elevation (≥ 1400 m in the High Tatras in Slovakia) and
native distribution of the hosts (Pinus and Larix) are reported to be crucial for the
occurrence of Phellinus vorax (= P. laricis) (Černý, 1989). Our observations
support this belief; P. laricis growing on Pinus mugo in the Bohemian Forest (=
Šumava Mts., Czech Republic) occurs under different climatic conditions than P.
pini inhabiting Pinus sylvestris in the adjacent area. While the only collection of P.
laricis there was recorded at ca. 1300 m, the highest elevation recorded for P. pini
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