Home – Home – Jornals – Contemporary Problems of Ecology 2023 number 5

Using nine nuclear microsatellite loci (nSSR), the structure of genetic variability of Scots pine in the Black Sea-Caucasus region, Eastern Europe, the Urals, Siberia and the Russian Far East was studied and the demographic history of these population groups was investigated using ABC-analysis. A significant differentiation between the populations of the Eastern Black Sea region and the main areal was confirmed, while the time of divergence between these groups was estimated at 0.5 million BP. The differentiation of the populations of the Greater Caucasus into western and eastern populations was found, probably due to migrations of Eastern European populations to the Western Caucasus. The nSSR similarity of the populations of the Crimea and Asia Minor is shown, probably as a result of their relatively recent differentiation. The nSSR analysis revealed a significant differentiation between the populations of the Russian Far East and the rest of the populations of the northern part of the range. The divergence time between these groups of populations was estimated using ABC-analysis at 97 thousand BP, which confirms the survival of the scots pine in the Russian Far East during the last glacial maximum.

Results of karyological and cytogenetical studies in populations of conifer species of Pinaceae and Cupressaceae families from extreme conditions are summarized. In conifers growing in southern and northern borders of areas, on ecological limits of distribution, in anthropogenically disturbed ecosystems, at the introduction, chromosome variability is revealed. A high frequency of changes in the number of chromosomes (mixoploidy, aneuploidy and polyploidy) and their morphology were noted. Different types of chromosome anomalies (ring and polycentric chromosomes, fragments, multiple chromosome irregularities), B-chromosomes occurrence, irregularities of mitosis and meiosis are found. Using classical methods and fluorescent in situ hybridization (FISH), studies of the polymorphism of the nucleolar regions of chromosomes were carried out, and features of the loci of the 5S and 45S ribosomal RNA genes were revealed.

A study of morphological traits in populations of R. aureum from the Western and Eastern Sayan and Kamchatka was carried out. The variability of genetic nuclear DNA microsatellite markers (nSSRs) was studied in the same samples. A total of 15 absolute and relative morphological traits of shoots and leaves, as well as 18 polymorphic microsatellite markers in 8 natural populations of R. aureum were observed. It was found that the following parameters were the most variable within species populations: plant size, shoot length, length of the foliated part of shoots and number of leaves relative to shoot length; more stable parameters were relative leaf shape parameters. Reliable division of populations into 3 geographical groups on all set of morphological characters is established. A great contribution to the division of geographical groups of populations and individual populations of an important taxonomic character - the duration of leaf life on the shoot was noted. The revealed structure of morphological differentiation of populations is confirmed by the results of the analysis of genetic variability of the same populations of R.aureum by nuclear microsatellite markers. The greatest genetic distances from other populations are established for Kamchatka populations. There is a tendency to differentiation of populations within the Altai-Sayan mountain country. The results of the study agree well with the information on geography, ecology and biology of the species. The study of intra- and interpopulation morphological differentiation of R. aureum populations in Siberia was conducted for the first time, following the recently initiated studies on genetic variability of the species in Northern Eurasia.

The results of the analysis of nuclear microsatellite loci (nSSR) for studying the genetic diversity of natural populations of Scots pine (Pinus sylvestris L.) in the southern taiga and forest-steppe of Middle and Western Siberia, affected by fires and logging of different intensity, are presented. Six polymorphic loci suitable for studying the genetic variability of the populations of the species in Siberia were selected. The set of genetic markers used by us has not been studied yet in the Siberian part of the species range. Population genetic studies were carried out in 13 Siberian populations of Scots pine (26 samples) based on selected nSSR markers (psyl57, PtTx2146, lw_isotig04195, lw_isotig04306, lw_isotig10603, lw_isotig21953), containing a total of 62 alleles. 15 of them were found only in any one (two) of the populations, and can be used to study the spatial and population structure of the species and determine the geographical boundaries of the populations. It has been established that their variability is significantly higher compared to isoenzyme markers, they contain a significant number of rare and very rare alleles and are quite informative for the purposes of genetic monitoring and assessment of the impact of forestry activities and other natural and anthropogenic damaging factors on intrapopulation genetic diversity and the sustainability of one of the main forest-forming coniferous species of Siberia. In the process of analyzing the similarity of populations of the species according to the studied markers, a certain relationship was revealed between the genetic differentiation of populations and their geographical location, which is often not detected when using isoenzyme markers.

Betula pendula Roth. is tolerant to tehchnogenic air pollutants. However, the viability of pollen decreases under stress conditions, as well as under air pollution. The researches were conducted in Middle Siberia on eight plots of motley birches near industrial city of Krasnoyarsk. In each plot on west side of 15-20 trees, male twigs were cut at pollination time. Pollen was extracted from the male generative organs for size and viability (potential, by starch test, and realized, by in vitro germination) determination. The results were analyzed by statistical methods. The researches have revealed reduction of pollen viability under technogenic pollution and reliable differences in pollen grain diameters under different growing conditions, whereas deformed pollen grain were not revealed. The variability of pollen grains in diameter in the biocenosis did not exceed 9.3-9.9 %. Maximum number of sprouted pollen grains observed under background conditions, and minimum at the eastern border of city in the main direction of the transfer of technogenic aerosols. The length of pollen tubes in trees growing under these conditions decreased by more than twice in comparison to the critical value (namely, pollen grain diameter of 18-20 µm). Regression analysis has shown correlations between pollen germination and accumulation of dust on foliage, as well as of lead and aluminum content in the foliage ( r = - 0.1-0.3, р ≥ 0.05)). In spite of tolerance of the species to air pollution, Betula pendula male generative structures are sensitive to the contamination. Pollen viability can be used as a bioindicator of environmental pollution at monitoring.

The paper presents the results of field tests and chromosome analysis for five micropropagated clones of triploid white poplar (Populus alba L.) and grey poplar (Populus × canescens Sm.), which are of a mixoploid nature. In order to assess ecological and genetic potential of the plants they were tested in different edaphic conditions. It was found that the clones (genotypes) in the age of 2-23 years grown on black soil (chernozem) had better survival index, preservation rate, growth and health state than the same clones grown on poor dry acidic sandy loams. Under conditions of edaphic stress, clones had a higher cytogenetic polymorphism and heterogeneity of somatic cells (compared to chernozem). Apparently, the genetic and presumably epigenetic variability, manifested in a change in the degree of mixoploidy (the ratio of cells of different levels of ploidy) depending on environmental conditions and the nature of gene expression (an increase in the proportion of cells with residual nucleoli in the metaphase of mitosis), can provide the most effective implementation of the functions of genes for the adaptation of clones in adverse conditions. The study demonstrated that the response of clones to adverse growing conditions largely depended on their genotypic characteristics (including characteristics of the species). The clone of the grey poplar had the highest ecological plasticity. This clone has a broad genetic basis (it is a hybridogenic species, mixoploid, allotriploid), which expands the possibilities for its use in various growing conditions. Micropropagated clones of the white poplar execute their production potential (growth) on chernozem or alluvial soils.

DNA polymorphism of cenopopulations Larix sibirica Ledeb. and Picea obovata Ledeb., growing in different ecological conditions of the southern part of the Taimyr Peninsula, was studied, their genetic diversity in nuclear microsatellite loci was estimated: N_a = 3.30, N_e = 1.75, H_o = 0.263, H_e = 0.366 - in L. sibirica and N_a = 2.92, N_e = 1.59, H_o = 0.351, H_e = 0.338 - in P. obovata. In general, a deficiency of heterozygous genotypes (F = 0.177) in the studied populations of Siberian larch, and an excess of heterozygous genotypes ( F = -0.051) in populations of Siberian spruce were noted. The genetic features of these species under the influence of technogenic emissions in the Norilsk industrial region were examined. In L. sibirica, a higher allelic diversity and a higher level of inbreeding were found in the cenopopulation from an ecologically safe area, while a higher level of heterozygosity and a lower value of the inbreeding coefficient were noted in the area with an increased level of pollution. Comparison of the cenopopulation samples of P. obovata showed that the genetic structure of the stand from the ecologically favorable area is practically in equilibrium, while a 10 % excess of heterozygotes is recorded in the more polluted area. Despite certain differences between the two studied species, in general, cenopopulations of L. sibirica and P. obovata growing in the areas with an increased, but acceptable level of technogenic load in the Norilsk industrial region are characterized by higher values of almost all parameters of genetic variability. We suggest that this pattern reflects the activation of adaptive processes in coniferous populations from extreme growing conditions.

The article presents the results of a comparative analysis of the radial increment of various larch species and provenances growing on a common ecological background in experemental forestry established in 1965-1967 on the Krasnoyarsk forest-steppe territory by employees of the Sukachev Institute of Forest SB RAS. The provenances of Siberian larch (Larix sibirica Ledeb.) from different elevation belts of the Southern Siberian Mountains, Gmelin larch (L. gmelinii Rupr.) from the Trans-Baikal and Zeya provinces (Eastern Siberia), as well as Japanese larch (L. leptolepis Gord) introduced from Sakhalin Island were studied. Based on the cluster analysis of radial growth series, four groups of provenances were identified with different growth strategies depending on the response to environmental factors: mountain-forest-steppe and mountain-taiga provenances of Siberian larch; provenances of Gmelin larch from Transbaikalia. The provenance of Japanese larch from Sakhalin Island has formed a separate cluster. The highest values of radial growth were found in groups of mountain-forest-steppe provenances formed by Siberian larch and Gmelin larch trees introduced from East Siberian provinces. Low values of radial growth were noted in provenances of Siberian larch trees from Southern Siberia mountain-taiga zone and Japanese larch from the Sakhalin Island. Dendroclimatic analysis was used to identify the relationship between the environmental variables of the introduction zone and the radial increment of the studied provenances. In the Krasnoyarsk forest-steppe, the main factor limiting radial growth is the moisture content of the root layer in the middle of the growing season (July - August). Larch trees introduced from wetter habitats respond more strongly to an increase in water stress, while radial growth of trees taken from drier habitats responds positively to an increase in the length of the growing season.

The genetic differentiation of Siberian larch (Larix sibirica Ledeb.) populations in the latitudinal gradient of climatic conditions was studied based on high-throughput double digest restriction-site associated DNA sequencing (ddRADseq) data. We studied the correlation of five main climatic variables with the variability of 47,929 single nucleotide polymorphisms (SNPs). A total of 125 trees were studied: 61 trees in four populations along the western geographic transect and 64 trees in four populations along the eastern geographic transect. 21 SNPs with signatures of selection were identified, including 9 outlier SNPs whose variability cannot be explained by selectively neutral processes, and 12 SNPs whose variability correlated with the environmental factors. Seven SNPs are located in the introns of mitochondrial genes, three are located relatively close to the mitochondrial genes encoding NAD2 and ribosomal proteins S7 and S11, one is located at a distance from the nuclear gene encoding a protein homologous to the microtubule-associated futsch-like protein of Arabidopsis thaliana, two in the protein genes of an unknown nature and three in contigs containing no genes, and for which no homologous sequences were found in the NCBI GenBank.

Dynamics of tree height of Scots pine (Pinus sylvestris L.) of different origin was studied in the provenance trial on sandy and loam soils in Central Siberia. Plots with different soils are situated in the one geographical point in the Boguchany region in Krasnoyarsk krai. It has common climatic conditions. Different adaptive reaction of pine climatypes posterities to soil conditions and other ecological factors was revealed in the place of trial. Differentiation of Scots pine climatypes at mean height are shown in the article. Perspective climatypes were distinguished on base of growth dynamics.

The Siberian spruce (Picea obovata Ledeb.) pollen viability was studied on the border of Krasnoyarsk city as well as unpolluted growth conditions. The study discovered the variability and correlation between the functional characteristics of pollens, as well as a low rate of development anomalies. The viability of pollen growth in forest ecosystems of the Eastern Sayans middle mountains (northeast border of national park “Krasnoyarskie Stolby”) decreased under pollution press. A great variety of pollen viability characteristics of the Siberian spruce pollen makes evident the high degree of flexibility and adaptability of species′ reproductive processes.

The results of cytogenetic analysis of four embryogenic cell lines of Siberian larch (Larix sibirica Ledeb.) of different ages: young (two four-month and 16-month CLs) and long-proliferating (11-year CL) are presented. Three cell lines are diploid and contain in the karyotype the normal number of chromosomes for this species (2n = 24). A 16-month-old CL capable of forming somatic embryos was aneuploid (2n = 25). This cell line is probably characterized by trisomy on one of the pairs of submetacentric chromosomes. The long-term proliferating CL, from which regenerants and clones were obtained, retains a diploid number of chromosomes during 11 years of cultivation and remains genetically stable. The karyotype of conifers is characterized by high degree of stability and most of the species contain 24 chromosomes (2n = 24). Therefore, the detection of cytogenetically stable cell lines is of great interest for genetic work of this group of plants and creation of highly productive plantations with specified hereditary properties.

With the use of six polymorphic microsatellite markers of nuclear DNA in the territory of oil complex of Western Siberia’s activity, a pilot study of three closely spaced populations of Pinus sylvestris L. - bog land, dry land, and "technogenic" (originated on the sandy base of the drilling pad) was carried out. It showed that the studied populations are quite close in terms of the main parameters of genetic variability, assessed by six polymorphic loci. At the same time, small but statistically significant differences were found between the dry land and bog land populations, including one’s in FIS. The "technogenic" population has an intermediate position between the studied natural populations and does not show statistically significant differences from them. It has been suggested that the most likely cause of the latter is the formation of "technogenic" young pine stands from a mixture of genotypes of the dry land and bog land populations, as well as that the appearance of unique (private) alleles in the "technogenic" population and adjacent bog land population can be induced by chemical pollution.