Cytogenetic Damage of Human Somatic Cells and Weeping Birch Cells in Voronezh Districts with Different Levels of Anthropogenic Pollution

Cytogenetic parameters (the mitotic rate and the frequency of pathological mitoses) of the seed offspring of weeping birch (Betula pendula Roth.) and the frequency of micronuclei in the buccal epithelium of children living in several raions (districts) of the city of Voronezh differing in environmental conditions were studied. Judging from these parameters, the environmental situation was the worst in the Sovetskii raion. A correlation was found between the frequency of pathological mitoses in the roots of birch seedlings and the frequency of micronuclei in the buccal epithelial cells of children. This indicates that the cytogenetic monitoring data obtained in plants may be extrapolated to man.     

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.     

Specific Cytogenetic Characteristics of Pinus cretaceae and Pinus sylvestris

A comparative cytogenetic study has been performed in four populations of two pine species, Pinus cretaceae Kalen. and P. sylvestris L., growing on sandy and chalky substrates in Voronezh and Belgorod oblasts. Significant differences in the parameters of mitotic and nucleolar activities, as well as the rate and spectrum of mitotic pathology, between populations of P. cretaceae and P. sylvestris and between populations of P. cretaceae growing under different conditions have been found. Populations of P. sylvestris growing on sandy and chalky substrates differ from each other in nucleolar activity. These differences may be adaptive and reflect the characteristic metabolic patterns and biological plasticity of pines growing under specific conditions.     

Self-fertility in scots pine as a mechanism of resistance to chemical mutagens

Experiments on chemical mutagenesis have shown that the seed progeny of self-fertile Scots pine trees (generations M₁ and M₂) have increased resistance to supermutagens, since the frequency of mitotic pathologies in them has proved to be even lower than in the F₁ progeny of self-sterile trees chronically exposed to anthropogenic impact (automobile exhausts). This is evidence that the use of self-fertile forms in selective breeding for general and specific resistance holds much promise.     

Cytogenetic Variation in Populations of Scotch Pine

Cytogenetic variation was analyzed in daughter populations of Scotch pine from the Voronezh Forestry. The dependence of the variation on the method of seed collection (the commercial method; the population method, when seeds from a group of phenotypically normal trees in the center of the forest are collected; or the individual method, when seeds from plus trees are collected) and on the ecological situation at the sampling site (ecologically safe conditions or chemical or physical pollution) was studied. The parameters of the mitotic rate and mitotic pathology were estimated at 7–9% and up to 5%, respectively. These parameters may be considered as normal when estimating the quality of seed progeny in pine and when pine is used as a test object in cytogenetic monitoring. The limits of variation and the spectra of cytogenetic characteristics allowing the pine populations to maintain their homeostasis were also determined.