Home – Home – Jornals – Contemporary Problems of Ecology 2014 number 1

Modern phylogenies of plague agent Yersinia pestis (Logh.), built with the help of molecular genetic methods, do not provide satisfactory functional adaptation explanation and do not have enough ecological validity. An ecological scenario of the origin of the plague agent was proposed: original pseudotuberculous bacterium Yersinia pseudotuberculosis O:1b had moved to an unoccupied ecological niche (and a new adaptive zone) under ultra-continental climatic conditions of the late Pleistocene (Sartan Ice Age, 22–15 thousand years ago) on the territory of South Siberia and Central Asia. Intervening media, a parasitic system “tarbagan Marmota sibirica – flea Oropsylla silantiewi ” in which the genesis and adaptation of the plague agent had taken place, was characterized. This scenario, based on the main principles of modern evolutionary synthesis, opens the way to ecological-genetic synthesis in regard to the problem of plague origin. It also provides a fine model for developing of the theory of molecular evolution of pathogenic microorganisms.

Vibrio cholerae eltor strains with different epidemic importance isolated from river water in Vladivostok during the cholera outbreak (1999) and in Irkutsk during the disease-free period (2005) were used in the experiment. Biofilm structure consisting of a peripheral part, bundles, polysaccharide matrix, channels and polymorphic vibrios is presented using light and luminescent microscopy. Metachromatic pink colouring of the matrix (crystal-violet, toluidine blue) or fluorescent reddish-orange colour (acridine orange) indicate that acid mucopolysaccharides (glucosamineglucans) are present in its structure. Biofilm of a toxigenic strain is formed much later than the non-toxigenic strain biofilm, and the elements making its structure are more apparent. Viability of V. cholerae cells during the whole experiment (90 days) and preservation of initial pathogenic potential indicate high adaptive properties of V. cholerae eltor that provide its survival and reproduction in surface water reservoirs under favourable ecological conditions (optimum temperature, existence of a chitin-containing substratum, etc.).

Dynamics of reservoire potential (RP) and index of reservoir potential (IRP) of natural hosts of hantaviruses in the ecosystems of Primorskiy Krai was studied (from 2001 to 2010). Long-term average annual IRP for mice of genus Apodemus in the common reservoire potential amounted to 0,83, and IRP for A. peninsuale was 2 times higher than for A. agrarius ( t = 2,636; n = 18; р = 0,017). Predictive indices of a possible spreading of hantavirus infections on the territory of Primorskiy Krai were also denoted.

Regularities of the formation of Alpine flora of the Badzhal Mountain Range were described related to the specifics of natural and climatic conditions and history of development of the region.

Mycorrhizal symbiosis between plant roots and mycorrhizal fungi are almost ubiquitous. These interactions contribute a largely to soil autotrophic respiration (R_A), influence soil heterotrophic respiration (R_H) and respond strongly to such climatic changes as temperature and precipitation. The aim of the present study was to explore how variation of temperature and precipitation influence R_A and R_H in global forest ecosystems that are classified by the mycorrhizal type of the dominant plants. The results show slight variation for R_A and significant change for R_H among different mycorrhizal strategy types. In forests with predominating arbuscular mycorrhiza (AM) the R_A and R_H are trifling higher than in non-AM type forests. The responses of R_A and R_H to temperature and precipitation were highly variable among different mycorrhizal strategies. For example, the changes of R_A and R_H are more dependent on precipitation than temperature in AM-forest, and temperature accounted more for their variations in forests of the other three mycorrhizal types. As far as we know, this study was the first to evaluate the influence of different mycorrhizal strategies on forest R_AA and R_H and their response to temperature and precipitation.

Eighty species of macromycete were detected as the result of studying the biota of agaricoid and gasteroid fungi growing in dryad tundras of Altai-Sayan mountain area; 19 of them were first to be found in South Siberia. The basis of microbiota comprised species of arctoalpine element (37,5 % of the total number of species) and multizonal element (22,5 %) of families Russulaceae, Cortinariaceae, Strophariaceae and genera Cortinarius, Inocybe, Russula. On the trophic level mycorrhiza-formers (22,5 % of the total number of species) and humic saprotrophs (17,5 %) predominated.

Species composition and evolution dynamics of cyanobacteriae and algae of Lake Kalatch (Omsk region) were studied. The studied cyanobateriae and algae proved to be highly abundant and had little floristic affinity to phytoplankton. Small-celled cyanobacteriae and Chlorococcales predominated. The term “cryophyton” was suggested to describe photosynthetic organisms living in the ice.

The article presents the results of investigation of genetic diversity, structure and the degree of differentiation of “island” Scotch pine populations ( Pinus sylvestris L.), growing on the territory of South Siberia (south of Krasnoyarskiy krai, Khakasia, Tuva, Buryatia) and in the north-eastern part of Mongolia. Twenty isoenzyme loci had been analyzed to obtain the given results.

Investigation of phenotypical variety of cones and seeds in southern Siberian Scots pine populations (Krasnoyarskiy krai, Khakassia, Tuva, Buryatia) was carried out using the methods of A. I. Vidyakin [2004]. The analysis was conducted on the basis of 5 index features and 6 qualitative features. The populational level of 7 features was confirmed. These features also proved appropriate to be used as markers of genetic variability of southern Siberian Scots pine populations.

The link between productivity of aboveground and underground biomass and variability of electrophoretic spectra of seeds polypeptides was established on the basis of the analysis of 6 populations of a valuable medicinal species – Hedysarum theinum Krasnob. The protocols for microclonal propagation of perspective samples were developed. The most efficient multiplication was achieved in MS medium supplemented with 5 µM BAP, 200 mg/l of glutathione and 200 mg/l of casein hydrolyzate. The shoots were successfully rooted on half strength MS basal medium supplemented with 7 µM NAA.

During the vegetational seasons in 1976-2005 respiration and growth of vegetative organs of model Scots pine trees at the climax stage of their current increment in forest steppe of Baikal area were studied. The study of respiration was based on the strong connection between respiration of vegetative organs, its growth and temperature. Respiration rate was measured using area-based and oven-dry weight estimation. Regardless of the basis of the study, vegetative organs respiration rate decreased from apical meristems in the direction of the organs’ base. The relation between respiration of above- and underground organs appeared to be 3 : 2 and almost 2 : 1 respectively. During the period of study the Scots pine respiration rate increased approximately by two; average area-based respiration rate amounted to 32,8 and 36,9 kg of CO₂ respectively.

Differences in winter dormancy depth of Scots pine in provenance trials were revealed during the analysis of zero level of fluorescence parameters and chlorophylls and abscisic acid content. Obtained results correspond with the data received from the study of morphological features of needles and phenological observations. Trees of southern climatype, which differ in morphological features of needles and speed of phenophase transition, have deeper winter dormancy compared to the northern climatype. Due to climatic changes, trees of northern climatypes are expected to be more vulnerable during the periods of winter-spring thaws which previously were not typical for northern regions.

The article presents the analysis of seasonal, intra- and interpopulation variations in bioactive substances content in leaves of Nitraria sibirica Pall. Different areas in the south of West Siberian Plain and Altay-Sayan mountain region were taken into consideration.

It was proved that dwarf apple trees descended from tall-growing forms. This presumption was justified by comparative analysis of morphological features, ITS1 sequence identity and presence of genetic streams between the studied forms. It was also suggested that formation of dwarf forms in the present case is the initial phase of ecological speciation. Wide scatter of F_st values in different loci among the studied groups, ecologically mediated selection against hybrids and parallel formation of dwarf forms of apple trees all attest to this supposition.

The affect of temperatures and soil pollution by fluorides on the early growth stages of Crepis tectorum from polluted and unpolluted habitats was studied experimentally. The character and degree of combined influence of pollution and temperature; different directions of rebound depending on temperature, the studied index and origin of the population; variations in phenotypic flexibility in connection with temperature in polluted habitats were discussed.