A. B. Kholina

Characterization of gene pools of three Pinus pumila (Pall.) Regel populations at the range margins

Genetic variation of Siberian dwarf pine Pinus pumila (Pall.) Regel was characterized in three marginal populations in southwestern, southern and eastern parts of the natural species range (Baikal Area, Primorye, Kamchatka) using isozyme analysis. Analysis involving 16 isozyme loci encoding ten enzyme systems was conducted. Our results confirm that P. pumila is one of the most polymorphic species in the genus Pinus. Three marginal populations exhibited high genetic variation (P95 = 68.8%, Ho = 0.247, He = 0.291). Populations heterogeneity and significantly high level of divergence in coniferous (FST = 0.050, DN = 0.044) reflect their genetic originality. In summary, it was shown that the level of genetic variation characteristic for P. pumila in other parts of the not only is reproduced in the populations examined but even is close to maximum there.

Phylogenetic relationships of the species of Oxytropis DC. subg. Oxytropis and Phacoxytropis (Fabaceae) from Asian Russia inferred from the nucleotide sequence analysis of the intergenic spacers of the chloroplast genome

The nucleotide sequence analysis of trnH–psbA, trnL–trnF, and trnS–trnG intergenic spacer regions of chloroplast DNA performed in the representatives of the genus Oxytropis from Asian Russia provided clarification of the phylogenetic relationships of some species and sections in the subgenera Oxytropis and Phacoxytropis and in the genus Oxytropis as a whole. Only the section Mesogaea corresponds to the subgenus Phacoxytropis, while the section Janthina of the same subgenus groups together with the sections of the subgenus Oxytropis. The sections Chrysantha and Ortholoma of the subgenus Oxytropis are not only closely related to each other, but together with the section Mesogaea, they are grouped into the subgenus Phacoxytropis. It seems likely that the sections Chrysantha and Ortholoma should be assigned to the subgenus Phacoxytropis, and the section Janthina should be assigned to the subgenus Oxytropis. The molecular differences were identified between O. coerulea and O. mandshurica from the section Janthina that were indicative of considerable divergence of their chloroplast genomes and the species independence of the taxa. The species independence of O. czukotica belonging to the section Arctobia was also confirmed.

Genetic Variation in Six Species of the Genus Oxytropis DC. (Fabaceae) from Kamchatka Peninsula

Using the isozyme analysis, genetic variations in six species of the genus Oxytropis DC. (Fabaceae) from Kamchatka was assessed. It was demonstrated that diploid species from the section Arctobia were characterized by a low level of variations typical of endemic plant species. At the same time, polyploid species from the Orobia section demonstrated very high values of the heterozygosity parameters (Ho varied from 0.200 to 0.274). It has been suggested that the level of polymorphism of the oxytropes from Kamchatka was shaped as a result of the interaction of a number of factors, among which the most important are the ecological confinedness of the species, the specific features of the reproductive system, and gene drift. In the species of Orobia section, it is also the presence of the polyploid genome.

Genetic diversity of a rare species Aristolochia contorta Bunge (Aristolochiaceae) in Primorsky Krai

The herbaceous vine, twisted birthwort Aristolochia contorta Bunge, is a rare species listed in the Red Data Book of Primorsky krai (2008). On the northern boundary of its range (south of the Russian Far East), the species is represented by small isolated populations confined to the river drainages. Using allozyme analysis, genetic variation of nine natural populations of A. contorta (247 accessions), which represented the main part of the species range in Russia, was examined. The values of genetic variation indices (P = 22.7%; A = 1.28; Ho = 0.129; He = 0.101) were low and comparable with the data obtained for other rare plants. The proportion of unique genotypes (G/N) and Simpson’s genotypic diversity index (D) ranged from 0.32 to 0.64 and from 0.60 to 0.98, respectively. This means that A. contorta is characterized by sexual and asexual reproduction. Moreover, the ratio between these types of reproduction varied among the populations. Complete absence of inbreeding and excess of heterozygotes (FIS = −0.282), which was low probable in case of free mating, was observed. Evidently, clonal growth and (or) apomixis enables the species to maintain certain level of heterozygosity despite of small population sizes and non-regular gene exchange.

Seed Cryopreservation of Some Medicinal Legumes

Seed survival after storage in liquid nitrogen (–196°C) was examined in 12 wild medicinal legume species occurred Far East of Russia. Dry seeds of all species survived cryostorage without loss of viability. Initial germinability varied from 3 to 85%. The stimulatory effect of cryogenic temperature on germination, with or without subsequent chemical scarification, was observed in all species studied with deep physical dormancy or heterogeneous levels of hardseededness. Frozen seeds demonstrated higher germination percentages (the percentage of germinated seeds) and germination rates (time for first seed to germinate (T0) and time required (in days) to reach 50% of the final germination percentage (T50)) than the control ones. The anomalous seedlings were not observed after storage of seeds in liquid nitrogen. This study shows that cryostorage may be successfully applied for conservation of native species without detrimental effects on germination and growth.

Modern State of Populations of Endemic Oxytropis Species from Baikal Siberia and Their Phylogenetic Relationships Based on Chloroplast DNA Markers

The genetic diversity and population structure of the endemic species of Baikal Siberia Oxytropis triphylla, O. bargusinensis, and O. interposita were studied for the first time on the basis of the nucleotide polymorphism of intergenic spacers psbA–trnH, trnL–trnF, and trnS–trnG of chloroplast DNA. All populations of these species were characterized by a high haplotype (0.762–0.924) and relatively low nucleotide (0.0011–0.0022) diversity. Analysis of the distribution of variability in O. triphylla and O. bargusinensis showed that there was no significant genetic differentiation between populations of each species; the gene flow was 4.43 and 8.91, respectively. The high level of genetic diversity in the studied populations indicates a relatively stable state of these populations. A study of the phylogenetic relationships of closely related species confirms the concept of the origin of O. bargusinensis and O. tompudae as a result of intersectional hybridization of the species of the sections Orobia and Verticillares.

Genetic variation of the relict species Acanthopanax sessiliflorus (Rupr. et Maxim.) Seem. (Araliaceae) in Primorsky Krai

Based on the analysis of 17 genes encoding the allozyme diversity of 12 enzyme systems, data were obtained on the genetic variation of a relict of the Tertiary flora, a valuable medicinal plant Acanthopanax sessiliflorus (Rupr. et Maxim.) Seem. (Araliaceae) in the Russian area of its range. Indices of polymorphism for populations had rather high values on average (P95 = 42.4%, A = 1.55, Ho = 0.211, and He = 0.168), which are comparable with the known data for populations of A. sessiliflorus from the peninsula of Korea. The level of genetic diversity and its distribution among populations reflects the interaction of several factors, among which the most important are the historical past of the species, genetic drift, and the plasticity of the reproduction system. The obtained data can serve as a basis for the conservation of genetic resources of Far Eastern Araliaceae species.