RESUMEN
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 (H(o) 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.
Asunto(s)
Variación Genética , Oxytropis/genética , Diploidia , Enzimas/genética , Filogenia , Polimorfismo Genético , Poliploidía , SiberiaRESUMEN
Using allozyme analysis, genetic variation of two relict aquatic plants from Primorsky krai, Komarov lotus (Neliumbo komarovii Grossh.) and Gorgon plant (Euryale ferox Salisb.), was examined. The absence of allozyme variation in the Primorye populations of Neliumbo komarovii along with low polymorphism level in the population of Euryale ferox (P95 = 7.69; A = 1.07; Ho = 0.072; He = 0.038) was demonstrated. Since the data for the species examined are reported for the first time ever, the pheonotypes and genetic interpretation of the enzyme systems tested are presented. The izoenzyme profiles of N. komarovii were compared with the data reported for N. nucifera from China. The absence ofallozyme variation in N. komarovii, along with extremely low level of variation revealed for E. ferox, is discussed in association with the evolutionary histories of these species, their dispersal after the Pleistocene-Holocene cooling, and survival on this territory in range boundaries.
Asunto(s)
Genética de Población , Isoenzimas/genética , Nelumbo/genética , Nymphaeaceae/genética , Polimorfismo Genético , Fosfatasa Ácida/genética , Alcohol Deshidrogenasa/genética , Oxidorreductasas de Alcohol/genética , Organismos Acuáticos/genética , Aspartato Aminotransferasas/genética , China , Glucosa-6-Fosfato Isomerasa/genética , Glutamato Deshidrogenasa/genética , Fosfoglucomutasa/genética , Proteínas de Plantas/genética , SiberiaRESUMEN
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 ofA. 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 (F(IS) = -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.
Asunto(s)
Aristolochia/genética , Variación Genética , Heterocigoto , Reproducción/genética , SiberiaRESUMEN
Using allozyme analysis, genetic and genotypic variation of rare relict species, a member of one of ancient angiosperm families, Araliaceae, the clone-forming plant Oplopanax elatus (Nakai) Nakai, was evaluated. Electrophoretic separation of the enzymes is described, and genetic interpretation of the enzymes variation patterns is presented. The values of genetic variation indices obtained were low (P = 25%; A = 1.45: Ho = 0.131; He = 0.113) and comparable with the data reported for the rare plant species and the representatives of the family Araliaceae. The main factors responsible for the polymorphism level observed might be the evolutionary history of the species and gene drift. The level of genotypic diversity (G/N = 0.76; D = 0.97) was substantially higher, compared to the values reported for species with vegetative reproduction (D = 0.62). These results suggest certain contribution of the propagation by seeds in the formation of the species of interest.
Asunto(s)
Evolución Molecular , Flujo Genético , Oplopanax/genética , Polimorfismo Genético , Oplopanax/enzimología , Proteínas de Plantas/genéticaRESUMEN
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 (Transbaikalia, Primorye, Kamchatka) using isozyme analysis. Analysis involving 16 isozyme loci encoding ten enzyme systems was conducted. Our results confirm that P. pumila is among the most polymorphic species in the family 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 (F(ST) = 0.050, D(N) = 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.
Asunto(s)
Genes de Plantas , Pinus/genética , Pool de Genes , Sitios Genéticos , Variación Genética , Genotipo , SiberiaRESUMEN
Genetic structure of natural populations of the rare relict plant Manchurian birthwort (Aristolochia manshuriensis Kom.) in the Russian part of its area was analyzed using allozyme markers. The studied A. manshuriensis populations differed in the degree of their intrapopulation differentiation. The populations Nezhinka and Anan'evka were more differentiated (F(ST) = 0.1209 and 0.0576, respectively); these populations are located close in the regions of intense economic activity and are exposed to the strongest anthropogenic impact. A low degree of differentiation was detected in the population Malaya Borisovka (F(ST) = 0.0393), localized to intact habitats. The overall heterogeneity test has demonstrated that the population Malaya Anan'evka, exposed at present to small anthropogenic stress yet growing in disturbed habitats, displays no differentiation. These results suggest that at least three populations are influenced by genetic drift connected with a decrease in the reproductive and effective population sizes, which is caused, in particular, by anthropogenic impact. A high level of genetic similarity between the A. manshuriensis populations in Primor'e is discussed in connection with the evolutionary history of this species.
Asunto(s)
Aristolochia/genética , Variación GenéticaRESUMEN
Allozyme variation of a rare relict plant, birthwort Aristolochia manshuriensis Kom., was examined. The main parameters of genetic variation in natural populations of A. manshuriensis from the Anan'evka, Nezhinka, and Malaya Borisovka river basins (Primorskii Krai) were inferred from analysis of nine enzyme systems, presumably encoded by 18 loci. At 99% polymorphism criterion, 24.4% of A. manshuriensis loci were shown to be polymorphic. The mean number of alleles per locus was 1.24; the mean observed and expected heterozygosities, 0.12 and 0.10, respectively.