Phylogeography of Eurasian Larix species inferred from nucleotide variation in two nuclear genes

Abstract

Larch (Larix Mill.) is one of the most widely distributed tree genera in Eurasia. To determine population structure and to verify classification of five species and three varieties of the Eurasian Larix species, we investigated levels and patterns of nucleotide variation of two nuclear gene regions: the 4-coumarate coenzyme A ligase (4CL) and the coumarate 3-hydroxylase (C3H). In the 4CL region nucleotide diversity at silent sites (π sil ) varied between 0.0020 in L. gmelinii to 0.0116 in L. gmelinii var. japonica and in the C3H region between 0.0019 in L. kaempferi to 0.0066 in L. gmelinii var. japonica. In both gene regions statistically significant population differentiation (F ST ) was detected among adjacent refugial populations of some species suggesting limited gene flow and/or long time isolation of some refugial populations. On the other hand, populations of L. sukaczewii from northwestern Russia, which was glaciated 20,000 years ago showed no differentiation. This result is consistent with recent postglacial origin of these populations. Haplotype composition of some of the investigated Eurasian Larix species suggested that they are considerably diverged. Some haplotypes were unique to individual species. Our results indicate that more intensive sampling especially from known refugial regions is necessary for inferring correct classification of Eurasian Larix species and inferring their postglacial migration.

Colonization history of the sableMartes zibellina(Mammalia, Carnivora) on the marginal peninsula and islands of northeastern Eurasia

“…On the other hand, central Sakhalin is recognized as an important vegetation boundary, known as the Schmidt line (Miyabe and Tatewaki 1937). Phylogeographic analyses using nuclear and cytoplasmic markers for larch, spruce, and fir Abies species have revealed that central Sakhalin is a major area of introgression between old island colonists and subsequently migrated lineages (Aizawa et al 2007;Khatab et al 2008;Aizawa et al 2009;Polezhaeva et al 2010;Semerikova et al 2011). In the present study, the H1 lineage was observed in a relatively southern area on Sakhalin, whereas the R2 lineage occurred in the north (Fig.…”

Cytogenetic analysis of reciprocal hybrids and their parents between Larix leptolepis and Larix gmelinii: implications for identifying hybrids

“…Evidence from classical and molecular systematics, ecology, and crossing relationships all indicate L. leptolepis and L. gmelinii are closely related sister species Khatab et al 2008). This was also confirmed in the present study, where the high frequency of homoeologous chromosome pairing in reciprocal hybrids i Telophase-I of a PMC from L. leptolepis×L.…”

Phylogeography of Larix sukaczewii Dyl. and Larix sibirica L. inferred from nucleotide variation of nuclear genes

“…), there is still very little information about levels and patterns of nucleotide variation in coding regions of nuclear genome. As demonstrated in our recent study of the Eurasian Larix species, such information can give important insights into history and classification of this genus (Khatab et al 2008).…”

“…We also included sequence data for the partial region of the 4-coumarate: coenzyme A ligase (4CL) gene obtained in our previous study (Khatab et al 2008). We examined six populations of L. sukaczewii and three populations of L. sibirica.…”