G. D. Reunova

Phylogenetic Relationships of the Far Eastern Araliaceae Inferred from ITS Sequences of Nuclear rDNA

In eight species of the family Araliaceae, inhabiting the territory of the Russian Far East, the sequences of ITS regions of nuclear rDNA were determined. A comparison of these sequences enabled establishment of phylogenetic relationships between the Far Eastern and other members of the family. It was demonstrated that Aralia elata populations from Primorye and Sakhalin were genetically different and, hereby, could be classified as intraspecific taxa. Aralia continentalis along with A. cordata were attributed to the section Aralia sensu Wen. Oplopanax elatus and O. horridus were found to be very close to each other, possibly being the subspecies of one species or relatively young species. Legitimacy of the discrimination between two sections within the genus Eleutherococcus was confirmed.

Panax ginseng natural populations: their past, current state and perspectives.

AbstractAim:The mating system of Panax ginseng, genetics and ontogenetic structure of its natural populations of Primorye (Russia) were investigated.Methods:Genetic diversity was assessed using allozyme and the fluorescently based automated amplified fragment length polymorphism (AFLP) and simple sequence repeats (SSR) markers.Results:Total genetic diversity at species level is low with allozyme assay (0.023), and high with AFLP (0.255) and SSR (0.259) methods. It is observed within populations according to allozyme (>99%), AFLP (>85%), and SSR (>73%) assays. The indices of genetic variability distribution point out the re-colonization of the Sikhote-Alin by ginseng plants from southern refuges during the warming period in the early Holocene. The capability of ginseng plants to cross- and self-pollinate was shown and the assumption that Panax ginseng is a facultative apomictic plant was confirmed. The reproductive system of ginseng possesses high plasticity and stability of the fertilization process that help the species to survive in stress conditions. Disturbances caused by external or internal factors can be reduced due to the morphogenetic potential of ginseng ovule or apomictic embryo development. Analysis of life stages structure of ginseng populations demonstrates that all of them are not full-constituents because some life stages are absent or occur rarely.Conclusion:In all 3 populations, virgin and young generative individuals are predominant. This means that populations studied are viable and the reintroduction of natural ginseng population is possible yet.

Polymorphism of RAPD, ISSR and AFLP markers of the Panax ginseng C. A. Meyer (Araliaceae) genome

The genus Panax (Araliaceae) is world-famous because many its members have important medicinal properties. Panax ginseng C. A. Meyer is more popular than other species of the genus because remedies prepared from this plant stimulate immunity, help to prevent diseases, and have antistress effects. In addition, the ginseng root extract is traditionally used as a means against aging. At present, this species is found in the wild only in Primorsky krai, Russia, but its populations are extremely exhausted and need to be restored. In this study, effectiveness of molecular DNA markers in detecting genetic variation and differentiation of the ginseng populations was tested. Genetic variation of ginseng, identified using RAPD (P = 4%; Hpop = 0.0130) and ISSR (P = 9.3%; Hpop = 0.0139) markers was low. The AFLP* approach, according to which amplicons are separated in polyacrylamide gel and visualized by means of silver staining, showed somewhat higher variability (P = 21.8%; Hpop = 0.0509), while its effectiveness in population differentiation was as low as that of RAPD and ISSR. The AFLP** technique, which included analysis of the fragments using genetic analyzer, revealed high genetic diversity of ginseng (P = 94.4%; Hpop = 0.3246). All populations examined using the AFLP** markers were statistically significantly differentiated based on the AMOVA results. Our result suggest effectiveness of AFLP** markers for characterization of the genetic structure and genetic relationships of the ginseng populations. These markers are recommended for use in large-scale population genetic studies of this species to develop measures of its conservation.

RAPD and Allozyme Analysis of Genetic Diversity in Panax ginseng C.A. Meyer and P. quinquefolius L.

Inter- and intraspecific variation of two ginseng species Panax ginseng and P. quinquefolius was estimated by studying 159 RAPD and 39 allozyme loci. Parameters of polymorphism and genetic diversity were determined and a tree was constructed to characterize the differences between individual plants, samples, and species. Genetic variation in P. ginseng proved to be lower than in P. quinquefolius. Gene diversity in the total P. ginseng sample was comparable with the mean expected heterozygosity of herbaceous plants. This suggests that wild P. ginseng plants in various areas of the currently fragmented natural habitat and cultivated plants of different origin have retained a significant proportion of their gene pool. The mean heterozygosity calculated per polymorphic locus for the RAPD phenotypes is similar to that of the allozyme loci and may be helpful in estimating gene diversity in populations of rare and endangered plant species.

Genetic variability and population structure of endangered Panax ginseng in the Russian Primorye.

BackgroundThe natural habitat of wild P. ginseng is currently found only in the Russian Primorye and the populations are extremely exhausted and require restoration. Analysis of the genetic diversity and population structure of an endangered species is a prerequisite for conservation. The present study aims to investigate the patterns and levels of genetic polymorphism and population structures of wild P. ginseng with the AFLP method to (1) estimate the level of genetic diversity in the P. ginseng populations in the Russian Primorsky Krai, (2) calculate the distribution of variability within a population and among populations and (3) examine the genetic relationship between the populations.MethodsGenetic variability and population structure of ten P. ginseng populations were investigated with Amplified Fragment Length Polymorphism (AFLP) markers. The genetic relationships among P. ginseng plants and populations were delineated.ResultsThe mean genetic variability within populations was high. The mean level of polymorphisms was 55.68% at the population level and 99.65% at the species level. The Shannons index ranged between 0.1602 and 0.3222 with an average of 0.2626 at the population level and 0.3967 at the species level. The analysis of molecular variances (AMOVA) showed a significant population structure in P. ginseng. The partition of genetic diversity with AMOVA suggested that the majority of the genetic variation (64.5%) was within populations of P. ginseng. The inter-population variability was approximately 36% of the total variability. The genetic relationships among P. ginseng plants and populations were reconstructed by Minimum Spanning tree (MS-tree) on the basis of Euclidean distances with ARLEQUIN and NTSYS, respectively. The MS-trees suggest that the southern Uss, Part and Nad populations may have promoted P. ginseng distribution throughout the Russian Primorye.ConclusionThe P. ginseng populations in the Russian Primorye are significant in genetic diversity. The high variability demonstrates that the current genetic resources of P. ginseng populations have not been exposed to depletion.

Genetic Diversity and Relationships Among Siberian and Far Eastern Larches Inferred from RAPD Analysis

Genetic diversity of larches from six geographically distant regions, Tomsk, Irkutsk, Ulan-Ude (Siberia), and Blagoveshchensk, Khabarovsk, Yuzhno-Sakhalinsk (Far East) was examined by means of RAPD analysis. Tree DNA samples were compared using 457 RAPD loci (97% of which were polymorphic), identified with 17 primers of random sequences. In the samples examined, 32 to 49% of the genes were in heterozygous state, mean expected heterozygosity (Hexp) varied from 0.1373 to 0.1891, and the genetic distances (DN) for different sample pairs varied from 0.0361 to 0.1802. The main population parameters were determined for Larix sibirica Ledeb., L. gmelinii(Rupr.) Rupr., and L. kamtschatica (Rupr.) Carr. Analysis of the genetic relationships showed that L. kamtschatica was characterized by highest genetic differentiation from the other larches examined, while larches from Primorskii krai were genetically close toL. sibirica.

Genetic Variability of Iris setosa

Genetic variability of Iris setosa Pall. ex Link. was studied by the RAPD method. Plants from three different habitats were compared by 135 loci revealed with eight arbitrary primers. The three plant accessions all exhibited a high level of polymorphism, and each was characterized by different frequencies of polymorphic fragments, which probably reflected the geographic isolation of the analyzed populations. The average level of polymorphism detected was 35%.

RAPD Analysis of Genome Variability of Planted Ginseng, Panax ginseng

Genome variability of 23 ginseng plants (Panax ginseng) grown in culture in Primorskii Krai was studied by RAPD method. Eleven arbitrary chosen primers were used to analyze 138 loci of DNA samples, 17 of which appeared to be polymorphic. The OPD-11-1000 fragment was found to be a RAPD marker allowing plants to be differentiated according to their morphotype. Using five primers, it was demonstrated that the genetic polymorphism of the cultivated plants is lower than that in nature (7.6% and 10.6%, respectively). Dendrograms of genetic relatedness are in accord with genetic differences between individuals of plantedP. ginseng belonging to different morphotypes, and demonstrate close relatedness of one of the morphotypes to wild plants. This morphotype could be recommended for reintroduction into natural habitats.

Genetic Variability and Differentiation in the Larch Populations within the Range of Larix olgensis A. Henry in Primorye

The level of within-and among-population variation of larch inhabiting the range of Larix olgensis A. Henry in Primorye was estimated on the basis of 440 RAPD loci identified by means of 12 random primers. In ten populations examined, the proportion of polymorphic loci was 35–60%, the average expected heterozygosity varied from 0.1340 to 0.2169, and the average gene flow estimate was 1.38. According to Fisher’s test for heterogeneity, the pairwise differences of the fragment frequencies between the populations were statistically significant. The subdivision index GST = 0.2663 indicated that the interpopulation variation component accounted for approximately 27% of the total variation. Coefficients of Nei’s genetic distance between the populations varied from 0.0137 to 0.0934. Most of the samples with high support clustered according to the geographic positions relative to one another within the range. These results suggest that the populations examined are characterized by high genetic variation, like the larch populations of Siberia and the Russian Far East studied earlier, but, in contrast to the latter, exhibit higher among-population variability.

Genetic Relationships among Far Eastern Species of the Family Araliaceae Inferred by RAPD Analysis

A molecular genetic study of Far Eastern species of the family Araliaceae by means of RAPD analysis was conducted. Using 21 primers we assessed variability at 595 loci. Based on matrices of genetic distances D, dendrograms of genetic relationships among eleven species of this family were constructed. Our results suggest that Acanthopanax sessiliflorus and Eleutherococcus senticosus belong to different genera, Aralia cordata andA. continentalis are different species, and A. elata and A. mandshurica probably cannot be regarded as distinct species. Genetic similarity of Far Eastern A. cordata and American A. hispida is shown.