[Adaptation of the Seed Reproduction System to Conditions of Maritime Antarctic in Deschampsia antarctica E. Desv.].

Deschampsia antarctica E. Desv. is one of the two flowering plants that, along with Colobanthus quitensis (Kunth) Bartl., was able to settle the ice-free areas of Antarctica. In order to identify the possible adaptations of the D. antarctica reproductive system to adverse environmental conditions, comparative cytoembryological analysis of plants of this species growing on the Antarctic Peninsula with plants of the closely related species D. beringensis Hult. from the Kamchatka Peninsula was conducted. It was found that both species are characterized by sexual mode of reproduction, equal size of pollen grains (25.5 ± 2.2 and 26.2 ± 1.9 µm, respectively), same features of the embryo sac structure, and emryo- and endospermogenesis. Interspecies differences have been found in mature embryo sac size (326.8 ± 12.8 and 161.7 ± 10.4 µm), pollen sterility percentage (86.1 ± 8.9 and 35.3 ± 9.2%), and quantity of pollen in the anthers (140 ± 15.3 and 1578 ± 88.6). Possible causes and significance of these differences are discussed. No unique adaptations of seed reproduction system that are inherent exclusively to D. antarctica were found. The D. antarctica reproduction strategy is based on the combination of autogamy (and its extreme form cleistogamy) with production of excess pollen quantity for its mode of pollination.

[INTRASPECIFIC CHROMOSOME POLYMORPHISM OF IRIS PUMILA L. FROM THE TERRITORY OF UKRAINE].

Cytogenetic analysis of Iris pumila L. plants from different habitats in Ukraine revealed the intrachromosomal polymorphism. Chromosome number 2n = 32 was established for plants of this species. Root meristem of I. pumila seedlings of all populations showed high level of mixoploidy. The differences in the percentage of aneuploid cells and anaphase aberration were found between the sampled populations. Anaphase analysis revealed the level of chromosomal rearrangements that reached 9.2% in some populations reached.

[CONTENT OF POLYCYCLIC AROMATIC HYDROCARBONS IN SOILS OF ANTARCTIC STATIONS REGIONS].

Comparative investigation of the soil contamination by polycyclic aromatic compounds (PAC) has been performed on examples of three polar stations of the Antarctic Peninsula. Data obtained are especially interesting for the Ukrainian Antarctic station "Academician Vernadsky" were no such investigations were performed since the technogenic spill of the hydrocarbons in 1992. Results of investigations permit to establish the values of the total background level of the PAC pollution as the base for the further monitoring of anthropogenic contamination. The data of analysis of soils from the all ecological zones of Point Thomas oasis (Polish Station "Genrik Artstovskiy") show the PAC homogenous background pollution to be similar to identified at the Galindez Island (the region of the station Academician Vernadskiy). Local pollutions are revealed in some areas of the Galindez Island. At the same time results of the investigation of the soils pollution from the various areas of the Fildes Peninsula (the station Bellingshausen.) show the absence of clearly pronounced contrast between the background and "hot points" that is likely related with the even pollution of the Peninsula. There was demonstrated the necessity of the development of regional standards and the establishment of a local background concentrations of PACs within the Antarctic Peninsula. At the same time, significant differences between the contamination of soils taken from the stations"Academician Vernadsky" and "Bellingshausen", apparently are associated with a lesser capacity of soils on the island Galindez that in the commensurable pollution creates greater concentrations in an investigated sample of the soil. There was shown the necessity of the development of the regional standard and the establishment of a local background concentrations of PACs within the Antarctic Peninsula.

[Genetic polymorphism of Gentiana lutea L. (Gentianaceae) populations from Chornohora Ridge of Ukrainian Carpathians].

The features of genetic structure and level of diversity were investigated for G. lutea populations from Chornohora Ridge of Ukrainian Carpathians using RAPD- and ISSR-PCR. We have shown a high level of genetic diversity for investigated populations. The differences between populations account for 59-72% of the total genetic variation, whereas intrapopulation polymorphism makes up 28-41%. The relationships among genetic variability level and ecological-geographical conditions as well as biological features of the species were assumed to be possible. The obtained results indicate the genetic isolation of G. lutea Chornohora populations from Ukrainian Carpathians. Pozhyzhevska agropopulation was characterized by a high level of polymorphism that means the possibility to use artificial plantings of the investigated species for its conservation.

The influence of some environmental factors on cytological and biometric parameters and chlorophyll content of Deschampsia antarctica Desv. in the maritime Antarctic.

Under the environmental conditions of the Point Thomas Oasis (King George Island, the South Shetland Islands), we studied the influence of month-long artificial treatment with fresh water, salt water, and guano solution on the biometric characteristics, chlorophyll content, as well as the nuclear area of leaf parenchymal cells and nuclear DNA content, in a maritime Antarctic aboriginal plant Deschampsia antarctica. The modeled factors induced an increase in the generative shoot height and the length of the largest leaf, but did not influence the number of flowers. Treatment with guano caused an increase in the chlorophyll a and b contents, while fresh water treatment only led to some increase in chlorophyll a. Fluctuations of physiologically significant traits, such as the nuclear area and DNA content in the leaf parenchyma cells of D. antarctica, have been traced under the influence of the studied factors. Understanding of the hierarchy of influence of these factors as well as and sensitivity of plants of this species to external agents require further investigation.

[Interaction of Ungernia victoris, Rhodiola rosea and Polyscias filicifolia plant extracts with bacterial cells].

Components of three investigated plant extracts obtained from biomass of Ungernia victoris, Rhodiola rosea and Polyscias filicifolia cultivated cells interact with OmpC and OmpF proteins-porins and decrease their activity of as receptors in regard to OmpC- and OmpF-dependent bacteriophages. Entrance into cell of these components optimizes LPS synthesis and promotes increasing of receptor activity both itself LPS and OmpA and LamB proteins tightly connected with it.

[Mixoploidy in wild and cultivated Cruciferae species able to hybridize with Brassica napus].

Chromosome numbers in root meristem cells of the seedlings of wild and cultivated Cruciferae species able to hybridize with Brassica napus have been studied. The seedlings of Brassica junceae, Diplotaxis tenuifolia and Raphanum raphanistrum showed exclusively diploid metaphases. Up to 5% of B. napus and B. cretica seedlings were mixoploids. Diploid cells prevailed among the mixoploids, but hypo- and hyperdiploid ones were observed as well. Nearly 20 % of B. campestris and R. sativum seedlings were mixoploid, and di-tetraploid chimeras constituted considerable proportion of them. Less than a half of B. nigra seedlings were diploid, while the rest of plants were mixoploid. Among them the seedlings bearing preferentially tetra- and triploid cells dominated. Biological implications and presumable reasons underlying the discovered mixoploidy are discussed.

[Dynamics of genome changes in Rauwolfia serpentina callus tissue upon the switch to conditions of submerged cultivation].

Genome of Rauwolfia serpentina callus cells was found to fail undergo the noticeable changes for several early passages upon the switch from surface to submerged cultivation in the liquid medium of special composition. After subsequent 4-6 passages in submerged culture RAPD spectra polymorphism was revealed which may reflect the changes in DNA sequence as well as in the structure of cell population that forms the strain. Introduction of the intermediary passage on the agar-solidified medium of more simple composition prior to transfer into liquid medium appeared not to affect essentially the level and the pattern of genome changes.

[Cytogenetic variation of Ungernia victoris cell lines during cultivation on culture media of different composition].

Chromosome numbers of U. victoris cell lines obtained from the same bulb and cultured for a long time on different agar-solidified and liquid nutrient media differed significantly. The components of the nutrient media including phytohormones did not influence the ratio of cells with different ploidy levels in various lines while transfer of the calluses to the liquid media resulted in the increase of diploid metaphase frequencies.

[Chromosome variability in the tissue culture of rare Gentiana species].

Cytogenetic analysis of plants and tissue culture of Gentiana lutea, G. punctata, G. acaulis has been carried out. Culturing in vitro was found to result in the changes of chromosome number in the calluses of the species involved. Species specificity for variation of the cultured cell genomes was shown. Contribution of the original plant genotypes to the cytogenetic structure of the tissue culture was established. Gentiana callus tissues (except for in vitro culture of G. punctata, derived from plant of Breskul'ska population) were found to exhibit modal class with the cells of diploid and nearly diploid chromosome sets.

[Bacterial test-system for a primary screening of the substances with potential anti-cancer activity].

A principle possibility of antitumour activity test in bacterial system represented by Escherichia coil of the wild type and its MS2-induced mutant has been shown. The initial bacterial strain is an indicator of toxic properties of the tested substances and the mutant one is a specific test-culture modelling a tumour cell. The comparison of the data described for eucaryotes with the data obtained using the proposed bacterial test system confirms an adequate response of both strains to the substances with the proved antitumour properties. The data are considered as very promising for the further improvement of this test system towards its application for primary screening of antitumour substances.

[18S-25S rDNA variation in tissue culture of some Gentiana L. species].

18S-25S rDNA of intact plants and tissue cultures of G. acaulis, G. punctata and G. lutea have been investigated by using blot-hybridization. The decrease of rDNA amount was found in the callus cultures as compared with the plants. In contrast to other species, G. lutea showed intragenome heterogeneity of rRNA genes as well as qualitative rDNA changes in tissue culture, in particular appearance of altered repeats. The relationship between the peculiarities of rRNA gene structure and their rearrangements in in vitro culture was suggested.

Variability of ribosomal RNA genes in Rauwolfia species: parallelism between tissue culture-induced rearrangements and interspecies polymorphism.

An analysis of 18S-25S and 5S rRNA genes in intact plants and cultured tissues of some Rauwolfia species was performed to compare these sequences variability occurred as a result of the species evolution in nature and that induced by tissue culture. The restriction fragment length polymorphism of 18S-25S and 5S rDNA was found both in intact plants of various Rauwolfia species and in long-term Rauwolfia serpentina tissue cultures. In addition, changes in the amount of 18S-25S rRNA genes were observed in long-term R. serpentina tissue cultures. The results demonstrate that rDNA variability observed in intact plants as well as in long-term cultures is attributed to differences in the same regions of ribosomal RNA genes.

[Biosynthesis of naphthoquinoine pigments in plants from Boraginaceae family in nature and in vitro culture].

Literature data on the production of naphthoquinoine pigment, shikonin, by the intact plants and cell cultures derived from the members of Boraginaceae family have been reviewed. The results of our own studies on generation of highly productive Arnebia euchroma cell lines able to accumulate up to 20% of shikonin in dry biomass are presented. Data on localization, application of naphthoquinoine pigments, peculiarities and enzyme control of their biosynthesis and transportation within plant cells and in culture in vitro are summarized.

[The influence of the extract of Ungernia victoris cultured cells and of some metal cations on Escherichia coli transformation with plasmid DNA].

In the system of cation-induced E. coli transformation by the plasmid pBR322 the effects of the extract derived from the biomass of cultured cells of U. victoris on the correlation between yield of transformants, viability of CaCl2 - treated cells and plasmid DNA conformation alterations has been investigated. The data obtained have been compared with effects of some salts of one- and divalent metals on the same parameters. The presence of different mechanisms of the variations of cell population viability and yield of transformants depending on utilization of salts or plant extracts has been shown.

[Variability of nuclear 18S-25S rDNA of Gentiana lutea L. in nature and in tissue culture in vitro]. / Variabel'nist' iadernoï 18S-25S rDNK Gentiana lutea L. v pryrodi ta v kul'turi tkanyn in vitro.

18S-25S rDNA sequence in genomes of G. lutea plants from different natural populations and from tissue culture has been studied with blot-hybridization method. It was shown that ribosomal repeats are represented by the variants which differ for their size and for the presence of additional HindIII restriction site. Genome of individual plant usually possesses several variants of DNA repeats. Interpopulation variability according to their quantitative ratio and to the presence of some of them has been shown. Modifications of the range of rDNA repeats not exceeding intraspecific variability were observed in callus tissues in comparison with the plants of initial population. Non-randomness of genome modifications in the course of cell adaptation to in vitro conditions makes it possible to some extent to forecast these modifications in tissue culture.

[Biosynthesis of poppy isoquinoline alkaloids in nature and in vitro culture. 2. Bracteum poppy (Papaver bracteatum Lindl.)]. / Biosintez izokhinolinovykh alkaloidov maka v prirode i v kul'ture in vitro. 2. Mak pritsvetnikovyi (Papaver bracteatum Lindl.).

Literature data and the data of the author's investigations on production of isoquinoline alkaloids by Papaver bracteatum Lindl. have been analyzed. Information on the methods of regulation and cell localization of morphine and sanguinarine biosynthesis is presented. The works studying differentiation processes in tissue cultures of bracteum poppy and relationship thereof with thebaine biosynthesis have been analyzed. Possible mechanism determining the induction of somatic embryos development and thebaine biosynthesis in the culture in vitro are proposed.

[Study of plant extract activity in the system of Escherichia coli unstable mutants]. / Vyvchennia aktyvnosti roslynnykh ekstraktiv u systemi nestabil'nykh mutantiv Escherichia coli.

Ability of cell biomass extracts of some medicinal plants to inhibit spontaneous segregation of new forms in E. coli MS2-induced unstable mutants system has been shown. The effect described is analyzed from the position of stabilizing activity of extracts concerning bacterial envelope membranes. The possible use of this bacterial system to study stabilizing effect as a separate stage of the known antimutagen protective action is discussed.

[Antimutagenesis as organism defense system against damaging factors of endogenous and exogenous origin]. / Antymutahenez iak systema zakhystu orhanizmu vid ushkodzhuiuchykh faktoriv endohennoho i ekzohennoho pokhodzhennia.

Antimutagenic system is represented as the system combining all enzymatic and metabolic processes of the organism at all levels. The problem of supporting of autoantimutagenic system with antimutagenic preparations is discussed. A number of possible mechanisms of antimutagenic action of different substances are considered.