[Adaptation to extreme environmental conditions and radiosensitivity of Yakutian plants].

The aim of the long-term research was to assess the influence of physiological, cytological and biochemical adaptations of the plants formed in conditions of extreme continental climate and permafrost on the radiosensitivity of their seed progeny. The obtained data were analyzed using comprehensive cytological and biochemical methods (author's) of the differential assessment of genome stability in reparation reactions and its overall activity. The data on the radiosensitivity of plants growing under permafrost conditions were obtained for the first time. Radiosensitivity of 50 species of wild plants in Central Yakutia was investigated and their classification into 4 groups of radiosensitivity was suggested. The correlation between the totality of biochemical properties of cells providing antioxidant and genomic protection and resistance to ionizing radiation was established.

[Effect of the physiological-biochemical characteristics variability on a radiosensitiveness of the Atriplex patula L. and Artemisia vulgaris L. ecoforms].

On the example of the physiological and the cytology-biochemical characteristics variability of an Atriplex patula L. and Artemisia vulgaris L. sprouts which parental plants were generated in various environmental conditions (South Yakutia, the Central Yakutia, Middle Ural), was shown, that radiostability depends not only on set protective antioxidant, on the DNA-reparation systems and on the vulnerability degree of a functioning genome, but also on the phenotypic diversifications of a population which in turn, in the certain degree, are consequence of previous selection of a population to all set of ecological stresses-factors of the environment.

[The effect of extracts from Rhododendron aureum Georgi and Artemisia yacutica drod. on wheat root meristem cells division]. / Vliianie ékstraktov Rododendrona zolotistogo (Rhododendron aureum Georgi) i Polyni iakutsko'i (Artemisia yacutica drod.) na delenie kletok kornevo'i meristemy prorostkov pshenitsy.

A study was made of the action of extracts from two Yakutian plant species in the course of mitosis in the rootlet meristemic tissue in germs of the local variety of common wheat. The examined extracts contain a large amount of biologically active substances and colchicine-like compounds causing (at certain dilutions) the increase in mitotic activity of the meristemic tissue in wheat germs, with simultaneous augmentation of the number of abnormal cells in mitosis, which well compares with the action of 0.01% colchicine solution.

[The effect of the biochemical adaptations in the Manchu alder (Duschecia fruticosa (Rupr)) to an elevated natural radiation background on the survivability of seedlings and on the radiosensitivity of its seeds]. / Vliianie biokhimicheskikh adaptatsii ol'khi kustarnikovoi (Duschecia fruticosa (Rupr)) k povyshennomu estestvennomu radiatsionnomu fonu na vyzhivaemost' prorostkov i radiochuvstvitel'nost' ee semian.

Seeds and sprouts of bushy alder existing for long under the condition of the enhances natural radiation background (ENRB; from 1.4 to 72.0 mCu/(kg.s)) have been examined to determine biochemical adaptations to permanent low-level irradiation. To achieve this goal a combined cytological and biochemical technique for the assessment of the activity of genome of the sprout root meristem in response to translation, replication and reparation has been applied. The activity of antioxidant systems has been studied. The data obtained allow us to reveal mechanisms of alder bush biochemical adaptations to various ENRB rates and their effect upon seeds radiosensitivity and sprouts survival. It is determined that the increase in sprout vitality and high radioresistance of seeds ripened under the conditions of low-level natural radiation is due to the content of low molecular antioxidants and activation of systems of genome reparation.