Data from: Cytoplasmic DNA variation and biogeography of Larix Mill. in Northeast Asia

Range-wide variation in 54 populations of Dahurian larch (Larix gmelinii)
and related taxa in Northeast Asia was assessed with four mitochondrial
PCR-RFLP and five chloroplast SSR markers. Eleven mitotypes and 115
chlorotypes were detected. The highest diversity was observed in the
southern Russian Far East where hybrids of L. gmelinii, L. olgensis and L.
kamtschatica are distributed. In contrast, only two mitotypes occurred in
L. cajanderi and L. gmelinii. The Japanese larch (L. kaempferi) was found
to be closely related to populations of L. kamtschatika inhabiting the
Kuril Islands and South Sakhalin, populations from the northern part of
Sakhalin being more closely related to continental species. In general,
both mitochondrial (GST = 0.786; NST = 0.823) and chloroplast (GST =
0.144; RST = 0.432) markers showed a strong phylogeographical structure
and evidence of isolation-by-distance. Yet both markers did not allow a
clear delineation of species borders. In particular, and contrary to
expectations, cpDNA was not significantly better than mtDNA to delineate
species borders. This lack of concordance between morphological species
and molecular markers could reflect extensive ancestral haplotype sharing
and past and ongoing introgression. Finally the distribution of mtDNA and
cpDNA variation suggests the presence of several refugia during
Pleistocene glacial intervals. In particular, mDNA and cpDNA reveal weak
but visible differentiation between L. gmelinii and L. cajanderi
suggesting independent glacial histories of these species.