Since the resent time DNA markers are widely applied for study of the genetic structure and biogeography of biological species. Modern genetic structure of boreal trees and shrubs is largely determined by the dynamics of their population size under the influence of late Pleistocene climate fluctuations. Uniparentaly inherited cytoplasmic markers have twice smaller effective population size and thereafter greater differentiating ability as compared to nuclear markers. In Pinaceae conifers mitochondrial (mt) DNA is maternally inherited and disperses through by seeds only, while chloroplast (cp) DNA is paternally inherited and disperses mostly by pollen. Larches are the dominant forest tree species of Northeast Asia with a large morphological variability over a broad range. During the last glacial maximum (LGM) about 20000 years ago accompanied by significant reduction of forest area it survived in the south of the Far East, as well as, presumably, on the northern coast of the Okhotsk Sea and in the other parts of western Beringia. The purpose of this study is to test hypotheses about the locations of larch glacial refugia and the assumption of migration routes in the investigated area during the Late Pleistocene based on the variation of the mitochondrial (PCR-RFLP) and chloroplast (cpSSR) markers. 54 populations of larch, about 1000 individuals in total, collected from natural habitats were analyzed. Four polymorphic fragments of mtDNA: nad5 (1-2r), nad4 (3c-4r), atpA and UBC 460 flank 1-2, as well as five chloroplast microsatellite loci - Pt26081, L-Pt30204, L-Pt9393, L-Pt9891and L-trnLV were studied. The combination of allelic variants in these loci identified 11 mitotypes (mtDNA loci) and 115 chlorotypes (cpDNA loci). The results of AMOVA analysis indicate a significant interpopulation differentiation, both with mitochondrial (NST = 0.820), and with chloroplast markers (RST = 0.450).Geographical distribution of mitotypes and chlorotypes was not uniform and reveals a few groups containing genetically related populations. 1. Both types of cytoplasmic markers showed genetic autonomy of Northeast Asia larches that were collected in the area of distribution of L.cajanderi. These populations were different from the populations located westerly the Verkhoyanskii Mt. ridge, thus supporting the existence of late Pleistocene refugia at the northern coast of the Okhotsk Sea and western Beringia. 2. Comparison of cpDNA and mtDNA variation reveals the complex origin of the larch in Kamchatka: it has chlorotypes that are common for the northeastern L.cajanderi, but fixed for mitotype that present with the low frequency only in the south of the Far East. Perhaps sometime in the past larch closely related to modern L.kamtschatica was widely distributed across the Northeastern Asia, however gone extinct during one of the last cold Pleistocene epoch surviving only in the Far East south and in Kamtchatka. Lately Kamchatka population came into hybrid contact with Dahurian larch occupying Northeast Asia in interglacial. Paleogeographic and molecular data about biogeography of other coniferous species (Picea jezoensis, Abies gracilis) support survival of larch on the peninsula during the LGM. 3. Maximum variability of cytoplasmic markers was found in the south of the Far East that is in agreement with the common opinion of the hybrid nature of larches distributed here. Japanese larch, L. kaempferi, was genetically close to populations from the south of Sakhalin and the Kuril Islands.

Note. Abstracts are published in author's edition