Phenes of Woody Plants: Identification,Scaling, and Use in Population Studies (An Example of Pinus sylvestrisL.)

The methods of identification and scaling of phenes of forest plants are described. The phene identification consists of five stages. Specific features of studies at each stage are shown using identification of the phenes of seed color, cone color, and seed scale structure in Scotch pine (Pinus sylvestrisL.) as examples. The method of phene scaling is based on the comparison of phene frequencies in a bog and in adjacent upland populations of pine. At the boundary between the bog and dry land, the frequencies of population-level phenes change, whereas those of superpopulation-level phenes remain unchanged.     

Reproductive isolation and disruptive selection as factors of genetic divergence between Pinus sylvestris L. populations

Generalizations are made on the basis of results obtained in the course of long-term, stationary quantitative studies on phenogenetic divergence of P. sylvestris populations growing in an upland bog and the adjacent dry land area in the pre-forest-steppe zone of Western Siberia. Contrasting differences between the two edaphoecotopes and almost complete phenological reproductive isolation of populations from year to year are demonstrated. It has been found that root morphogenesis in the F ₁ progeny of pine from the bog population grown under uniform ecological conditions in the dry land area is characterized by elimination of the vertical phenotype, with the alternative lateral phenotype type being dominant in 7- to 22-year seedlings. Significant allozyme differentiation and distinct chorological boundary between the dry-land and bog populations have been revealed. The hypothesis of their genetic divergence in the Holocene is proposed, with this phenomenon being explained by the cumulative effect of disruptive selection and strict reproductive isolation in two contrasting environments.     

Gradient Genogeographic Analysis of <Emphasis Type="Italic">Pinus sylvestris</Emphasis> L. Populations in Europe

Gradients of Nei's genetic distances between 15 samples of Pinus sylvestris L. trees were analyzed along three submeridional transects, from Scandinavia to the Mediterranean and Transcaucasia. As a result, distinct chorogenetic differentiation was revealed between the populations of this species growing in climatically specific regions of northern and southern Europe. Considerable Nei's distances (DN = 0.045–0.056) and their gradients, combined with differences in stable phenotypic characters (the composition of monoterpenes and morphological parameters of cones) determined at the Pyrenean and Caucasian mountain borders, suggest that the P. sylvestris species structure includes two South Eurasian subspecies, the Pyrenean P. sylvestris L., ssp. iberica Svoboda and the Transcaucasian P. sylvestris L., ssp. hamata (Stev.) Fomin.     

Population genetic structure of Pinus tabulaeformis in Shanxi Plateau, China

Chinese pine, Pinus tabulaeformis Carr., a species that ranges broadly across northeastern to southwestern China, plays a vital role in the maintenance of the structure and function of these ecosystems. In this study, we examined the genetic diversity of five widespread populations in Shanxi Plateau, the distribution center of Chinese pine, using 15 random amplified polymorphic DNA (RAPD) primers and five inter simple sequence repeat (ISSR) primers in 140 individual tree samples. Similar genetic differentiation results were obtained from the data of RAPD and ISSR. Based on the two sets of data, Nei’s genetic diversity was 0.2842 and 0.3078 and Shannon’s indices of diversity were 0.4332 and 0.4468. Genetic diversity at the species level was found high relative to that for other genera of Pinaceae. The greatest diversity was observed in the Lingkong Mountain population (0.3860), while the lowest was recorded in the Luya Mountain population (0.3352), most likely as a result of natural adaptation and anthropogenic perturbation. The relative magnitude of differentiation among populations (G _ST) was 0.1491 and 0.1356, respectively, implying that most genetic variation was within the populations (∼0.8509), rather than among populations. Published in Russian in Ekologiya, 2008, No. 1, pp. 36–42. The article was translated by the authors.     

Genetic differentiation of <Emphasis Type="Italic">Pinus mugo</Emphasis> Turra and <Emphasis Type="Italic">P. sylvestris</Emphasis> L. populations in the Ukrainian Carpathians and the Swiss Alps

The allozyme analysis of six local populations of Pinus mugo Turra and six populations of P. sylvestris L. in the Ukrainian Carpathians, Swiss Alps, and Schwarzwald has shown a higher polymorphism and greater interpopulation differentiation of the Carpathian group of P. mugo populations compared to the Alpine group (Nei’s genetic distance DN ₇₈ at the level of geographic population group is −0.023). A genetic differentiation of DN ₇₈ = 0.049 between these populations, which are isolated by a distance of more than 1000 km, has been found. This confirms the existence of the subspecies P. mugo ssp. mugo and P. mugo ssp. uncinata in the Carpathians and Alps, respectively. The hypothesis is put forward that the former subspecies has been formed in the Balkans and the latter, in the Pyreneans. It has been demonstrated that regional populations and geographic groups of P. sylvestris are less differentiated than those of P. mugo.     

Insularization and polymorphism in marginal island populations of <Emphasis Type="Italic">Pinus sylvestris</Emphasis> L.

Comparative allozyme analysis of 26 marginal island populations of Pinus sylvestris L. and 20 populations from the center of the species range has confirmed, at the species level, the Wright-Dubinin “island model” of automatic genetic processes and Mayr’s hypothesis about homozygotization of small isolated populations at range boundaries. It has been shown that the polymorphism of isolated populations sharply decreases when their area is reduced below 15–20 km² and increases to the level observed in the center of the range when the population area exceeds 50–100 km². A chorogenetic classification of marginal P. sylvestris populations is proposed.     

Morphophysiological responses of Pinus sylvestris L. and Picea obovata Ledeb. to industrial pollution under conditions of Northwestern Russia

Morphophysiological parameters of needles have been studied in Scots pine (Pinus sylvestris L.) and Siberian spruce (Picea obovata Ledeb.) trees of different life states growing under conditions of industrial air pollution with sulfur and heavy metals. Three functional clusters (tentatively named the initial, transitional, and disastrous clusters), each characterized by a certain metabolic status, have been revealed, and their quantitative and qualitative structure has been evaluated. The morphophysiological responses of pine and spruce are shown to be qualitatively different, depending on differentiation of trees with respect to vitality under conditions of industrial pollution. Probable factors accounting for these differences are discussed.     

Proliferative Activity of Corneal Epithelium and Specific Features of Morphogenesis in Postmetamorphic Rana arvalisNilss. in Urbanized Areas

The mitotic activity and sizes of corneal epithelial cells in postmetamorphic Rana arvaliswere studied in the populations exposed to different degrees of anthropogenic impact in the city of Yekaterinburg. The studies were conducted at the initial stages of frogs' terrestrial life in three consecutive years. Mitotic activity exhibited a slight positive correlation with the liver index, which indirectly reflects the general metabolic rate in young frogs. The combined estimation of proliferative activity, epithelial cell size, and relative liver weight had the highest information value. There was a relationship between the mitotic index and liver index in young frogs from habitats with the highest level of anthropogenic transformation. This indicates that morphogenesis is well-balanced and is likely to decrease the probability of morphological abnormalities in frogs developing in the unstable environment. This physiological property allows the populations to exist and reproduce in urbanized areas.     

The Spatiotemporal Structure of Rodent Populations in the Steppe Zone of Western Siberia

The spatial structure of populations has been studied in two rodent species inhabiting the subzone of meadow steppes of the steppe zone of Omsk oblast: the narrow-sculled vole (Microtus gregalis Pall.) and steppe lemming (Lagurus lagurus Pall.). Their populations are represented by combinations of territorial family groups whose structure and spatial distribution vary by season depending on population density, the phase of the population cycle, and the status of their members in the population. In the areas cohabited by M. gregalis and L. lagurus, the pattern of territory use and the rhythm of animal activity during the day depend primarily on their total density: under conditions of low density, the population groups of both species are spatially separated; at increased density, they are distributed with respect to the pattern of daily activity. Both species jointly use part of the territory but at different times of day: M. gregalis, mainly at night and in the morning; L. lagurus, in the daytime.     

Analysis of sensitivity of different criteria in cytogenetic monitoring

A sensitivity scale for criteria used in cytogenetic monitoring was constructed on the basis of published data and the results of experiments on exposingZebrina pendula Schirt. plants to radon at various equivalent volume equilibrium activities. It was found that nucleolar activity and suppression of mitotic activity are the most and the least sensitive parameters in terms of response to stress, respectively.     

Phylogenogeography and genotaxonomy of Pinus sylvestris L. populations

The phylogenogeographic structure, polymorphism, and differentiation of Pinus sylvestris L. have been studied for the first time by means of allozyme analysis of 143 populations along a network of transects covering the entire species range. The results show that the species in general is characterized by a significant level of differentiation, regardless of its relative uniformity in northern and central parts of the range. Nei??s genetic distances between populations and their gradients in the extreme southern parts of the range, where it has an insular pattern, are seven to eight times greater than in the northern, ??glacial?? zone. Three Pleistocene refugia for the species have been revealed in the Balkans, Southern Urals, and Northern Mongolia. Using analysis of genetic distances between 18 phylogeographic regions and an original genosystematic scale, one subspecies, five geographic races and nine geographic population groups have been distinguished in the P. sylvestris L. species structure.     

Morphogenesis of the Procumbent Life Form in Siberian Stone Pine at the Timberline in the Western Sayan Mountains

The morphology and development are described for Siberian stone pine (Pinus sibiricaDu Tour) growing at the timberline in the Western Sayan Mountains. Throughout ontogeny, these plants have a short stem trailing in an approximately horizontal direction. Maximal longevity and viability are characteristic of basal branches, which are able to root and produce vegetative generations. This allows these plants to be classified with the procumbent tree life form, in which the clones of most adaptive genotypes not only survive under extreme environmental conditions, but can also reproduce vegetatively.     

Role of genetic factors in landscape-geographic variation of the water vole (Arvicola terrestris L.)

The geographic variation of the water vole Arvicola terrestris L. has been analyzed with respect to two linear combinations of craniometric characters with the highest additive heritability (h ² = 0.59 and h ² = 0.52). The greatest differences have been revealed between the territorially close montane and piedmont populations. The lowland and montane populations have proved to differ to the smallest extent, despite their spatial and altitudinal separation. Selection under extreme conditions that leads to similar phenotypic results may be based on the common genetic background of these populations, irrespective of considerable distances between them and different environmental conditions in their habitats.     

A system of Pleistocene refugia for Pinus sylvestris L. in the southern marginal part of the species range

An allozyme analysis of 67 Pinus sylvestris L. populations distributed over the entire species range has provided a basis for determining locations of 12 hypothetical Pleistocene refugia (HPRs) in its southern marginal part and estimating their relative contributions to the gene pools of seven phylogeographic population groups (PPGs) in the glaciated zone of the range. Using Nei’s (1978) minimum genetic distances (DN78 < 0.015) reflecting similarities and differences in allele frequencies between PPGs and the refugia, it has been shown that the main contributions to the P. sylvestris gene pool in Central Europe, Scandinavia, and the Russian Plain were probably made by the Balkan and Southern Ural refugia, and in Western and Central Siberia, by the Southern Ural, Turgai, and Southern Siberian mountain refugia.     

Specific Karyological Features of Siberian Stone Pine (Pinus sibirica Du Tour) in Western Siberian Bogs

The results of a karyological study on Siberian stone pines growing in the bog demonstrated differences from the populations of this species studied earlier with respect to sizes of chromosomes and location of secondary constrictions. The number of nucleolar organizer regions in the chromosomes of Siberian stone pine trees growing in the bog was larger than in other populations. A wide spectrum of chromosome aberrations was revealed, which had not been observed in this species before. These were genome and chromosome aberrations of various types, as well as structural aberrations accompanied by changes in the number of chromosomes. It is assumed that the aberrations in the karyotype of Siberian stone pine resulted from stressful conditions.     

An outline of the theory of the genetic divergence of dry-land and bog populations of <Emphasis Type="Italic">Pinus sylvestris</Emphasis> L.

The thesis of the genetic divergence of Pinus sylvestris L. populations that have spread to bogs from the original dry-land populations has been deduced from the concept of the cyclicity of helio- and geophysical processes, derivative postulates on climatic cycles, formation of Holocene high bogs, contrasting differentiation between their environment and that of dry meadows, and the resultant changes in the vectors of microevolutionary factors and strong reproductive isolation between these populations. Logical genetic, ecological-phenotypical, and geographic consequences of this theory have been verified by factual data and general laws known to date. The interpolational and predictive roles of the new theory are demonstrated.     

Contributions of genotypic and meteorological factors to variation of annual tree increment in clonal scots pine plantations

Variation in radial increments of 28-year-old Pinus sylvestris L. clones in response to changes in weather conditions during the period between 1986 and 2007 has been studied in the Sredneobskii Bor pine forest. Significant genotypic differences in the adaptive reaction norm of the clones have been revealed. It has been shown that the contribution of genotypic differences to the total variance of test characters is usually significant and depends both on the conditions of growing season and on a given increment character.     

Geno- and Phenogeographic Analysis of Pinus sylvestris L. Populations along the Transect Extending from the Northern to Southern Boundary of the Species Range

Nei's genetic distances (Nei, 1972, 1978) between 12 Scotch pine (Pinus sylvestris L.) populations were determined using isozyme analysis. The gradients of these distances along the 1500-km meridional transect in the Transural Region and Northern Turgai from the pre-forest-tundra subzone (the Synya River basin) to the southern steppe (the Naurzumskii forest) were calculated. We discovered that the genetic distance gradients (GDGs) progressively increase in the direction from the northern boundary of the range to the southern boundary of the forest-steppe zone and sharply increase in the insular forests growing in the steppe zone. The results of cluster analysis and Mahalanobis distance gradients with respect to a set of morphological characters of the cones provide evidence that Scotch pine populations of the forest zone share somewhat the same gene pool, whereas the group of Scotch pine populations in the insular forests of Northern Turgai is obviously differentiated phenogenetically from the insular forests of the Tobol region, which grow farther to the north.     

Gradient analysis of the chrogenetic structure of lowland and highland scotch pine populations

Gradients of genetic distances (GGDs) between 26 adjacent cenopopulations of Scotch pine (Pinus sylvestris L.) along the transects through the distinct landscape-ecotopic isolation borders were analyzed graphically. The results made it possible to reveal and quantitatively estimate gradients and borders of gene-pool structural patterns in populations of this species in the central part of Northern Eurasia. In lowland areas, the most distinct borders were found between pine populations growing on dry lands and bogs (Pineta sphagnosa) in the forest zone of the Transural region, as well as between the Arakaragaiskii and Amankaragaiskii island pine forests in the steppe zone (Northern Turgai). In highland areas (the Urals and the Carpathians), the greatest GGDs were observed between low-mountain (about 600 m above sea level) and middle-mountain (850–900 m) populations. Analysis of GGDs is a promising gene-geographic method for determining population borders and studying the chorogenetic structure of species.