Visnyk of Dnipropetrovsk University. Biology, ecology

59-63

Authors: K. V. Derkach, O. E. Abraimova, T. M. Satarova, O. A. Molitva, V. S. Kalugina, M. G. Panasenko, S. S. Pechorna

In connection with the necessity of bringing elite maize inbreds of the Lancaster germplasm group, which have potential for cultivation in Ukraine, into the system of genetic tranformation, the aim of this investigation is to identify the ability of maize inbreds of this group to regenerate by direct organogenesis and to determine the optimal mineral basis for their nutritional environment using segments of the node area of shoots. As explantats we used sterile 4-day old seedlings of 4 maize inbreds of Lancaster germplasm and model inbred Chi31 exotic germplasm. The seedlings were obtained by germination of sterile seeds in Petri dishes between two layers of moist sterile filter paper at a temperature of 27 ºC in dark conditions. A single 1 cm long segment was cut from each from each seedling, running from 0.5 cm before the node to 0.5 cm after the node. A cut was made in each segment of the node in order to create a wounded surface. Explantats were planted in a nutrient environment with mineral bases of MS or N6, modified by the addition of 10 mg/l silver nitrate, 100 mg/l casein hydrolyzate, 690 mg/l L-proline, 30 g/l sucrose, 1.0 mg/l 2,4-dychlorphenoksiacetic acid and 0,1 mg/l abscisic acid. Cultivation was carried out at 25–27 ºC in the light. Direct hemogenesis in this environment on the 14th day of cultivation in vitro reached 100% for each line. This meant that all researched lines of Lancaster germplasm and the model line showed a high capacity for direct regeneration through direct hemogenesis, which does not depend on the composition of the mineral content of their nutritional environment. Callus formation was observed in all genotypes on the 14th day of cultivation in vitro and the extent of its formation increased during the following month of cultivation. The callus formation was observed only at the site of the wounded surface. The calluses were transparent. Although green areas appeared in these calluses, they were nonembryogenic and did not lead to regeneration. All explantats were transplanted into fresh nutrient media with simultaneous removal of germinated shoots on the 14th day of cultivation. Regeneration on the 45th day of cultivation took place by direct hemogenesis (formation of shoot or leafy structures) or direct hemoryzhogenesis (formation seedlings which had both shoot and root). Formation of ryzhogenic calli was observed in most inbreds. The frequency of regeneration of shoots and leaf structures was characterized by a tendency to increase indicators in the culture environment with mineral basis N6, and the frequency of regeneration of shoots was significantly marked using a medium with mineral basis MS. However, regeneration on the 45th day took place at a much lower rate than on the 14th day of cultivation, which must be taken into account when a system of genetic transformation systems using nodal segments of seedling shoots is being developed. Thus, using nodal sections of 4-day old seedling shoots of maize inbreds of Lancaster germplasm and model inbred Chi31, we can obtain viable seedlings for use in biological systems of agrobacterial transformation. We can recommend two variants of provoking regeneration by direct organogenesis in vitro for application in genetic transformation. The first variant suggests for all studied genotypes 100% induction on the 14th day of in vitro cultivation of direct organogenesis by hemogenesis and this requires further rooting of obtained shoots before planting into soil. Both variants of the nutrient environments of cultivation proposed us can be used. The second variant involves low frequency of regeneration by direct hemoryzhogenesis in a limited number of genotypes, but excludes the rooting stage. The cultivation environment with the mineral basis MS is recommended for this variant. The choice of either variant for obtaining direct regeneration depends on the particularity and aim of the research.

70-75

Authors: D. V. Chernetchenko, M. P. Motsnyj, N. P. Botsva, О. V. Elina, M. M. Milykh

A hardware-software complex automated system of recording bioelectrical potentials, which is based on a USB-device with subsequent processing of signals with PC was developed in this work. We proposed a universal scheme of registration of bioelectrical potentials, which allows one to detect the reaction of biological objects to different stimuli, such as cold, heat, photo- and electrical stimulation, and to different combinations of these stimuli (Motsnyj et al., 2004). They could be applied for deeper understanding of the biological mechanisms of generation of electrical potentials in cells and discovering the accommodation processes of organisms as a whole to these stimuli. The system for registration of bioelectrical potentials consists of hardware and software parts. The software part consists of the client and server sides, which transmit experimental data to the network. The client-side software renders a quantitative analysis and stores the results in a database. An integrated system of registration and biometrical processing was applied for analysis of the electrical responses of maize leaves to heat stimuli. The dynamics of these potentials were studied and a quantitative analysis of the potential level stabilization was made. We found that amplitude relation of responses to the initial response increased and stabilized at the level of 130%. Mathematical models of the plant cell for discovering intracellular mechanisms of biopotentials registration were developed. As a result of modeling, we found that the electrical response of the cells is based on selective conductance of the cell membrane for Н+ and K+ ions. By this way, we show the biophysical relation of plant potentials to intracellular biophysical mechanisms.

83-88

Authors: M. Tkachenko

We conducted a comparative analysis of the absolute and relative fecundity of round goby (Neogobius melanostomus (Pallas, 1984)) females in the Kakhovskyy Reservoir and the Azov Sea. We analysed the indicators of salinity, pH and oxygen levels in the waterbodies investigated. We determined the dependence of fertility of round gobies on body weight, length and age. This article presents the results of a comparative analysis with the works of other authors, including the results of a similar study conducted 40-years ago. We conducted cameral processing of the results by standard methodology. We counted the oocytes at varying stages of maturity. All oocytes were grouped by their diameter. We visually identified four groups of oocytes: 1700–2500 mkm – the large, mature oocytes (ІV stage of maturity); 400–1200 mkm – light yellow oocytes, which are ripening (ІІІ stage); 100–300 mkm (ІІ stage) whitish eggs, and the smallest (I stage) – up to 100 mkm. Stages II–IV were subjected to statistical processing. The differences between the indicators of fertility of fishes from saltwater and freshwater waterbodies show an increase in the relative and the absolute fecundity of fishes from the sea (saltwater) and decrease in the fecundity of the fishes in freshwater. The correlation analysis between the waterbodies and the length of the fishes showed 0.81 at the Kahovskyy Reservoir and 0.62 in the Azov Sea. The correlation analysis between the same waterbodies and the weight of the fishes was 0.63 and 0.74 respectively. This could indicate that conditions for the fishes’ existence were more favourable in the sea. The comparison analysis between our data and the 40-year old data for the Azov Sea depending on length and weight show a significant increase in oocyte numbers. This increase was noted for all size groups of fish. Nevertheless, the greatest differences were between fish in the Azov Sea (all data) and those in the Kahovskyy Reservoir. These results should be studied in the context of the nutrition spectrum and calorific objects of the round goby in these water bodies. It would be interesting to analyse data on gobies of the Azov Sea according to gradation in salinity levels.

95-100

Authors: S. O. Kochubey

We investigated the impact of the level of stochastic excitation of synaptic signals from pyramidal neurons on the generation of oscillations inside the interneuronal networks of the hippocampus with shunting GABAergic synapses. We used a modification of a mathematical model of the interneuronal networks (I. Vida, M. Bartos and P. Jonas, 2006) together with a model of external synaptic signalling with a Poisson distribution of time interval between events. We demonstrated that a completely synchronized synaptic signal when every interneuron in the network was impacted by an electric current with the same amplitude and frequency caused oscillations with a high level of synchronization (k > 0,9) in the network. The increase of synaptic signal frequency led to the respective increasing of oscillation frequency in the network. We demonstrated that a gradual increase of stochastic synaptic current from 0.001 to 0.200 causes reduction of synchronisation of oscillations in the interneuronal network from 0.89 to 0.11 with an equal signal frequency of 6 Hz. The frequency of oscillations in the interneuronal network also decreased from 55.6 to 35.7 Hz respectively for the levels of stochastisity 0.001 to 0.200 and the frequency of excitation of 58 Hz. Decrease of frequency and synchronization of oscillations in the network could be explained by the the inability of shunting GABAergic synapses to synchronize the work of separate interneurons when there is significant increase in stochastic external excitation. Besides this, we demonstrated the existence of a range of frequencies of the incoming signal of 30–40 Hz in the network, of which a significant increase of synchronisation of oscillations in the network takes place regardless of the stages of external stochastic excitation.

105-112

Authors: T. Shevtsova, E. Garkava, J. Brindza, T. Brjuzgina, V. Groza

Pollen has various effects on the human body. In order to study and compare the biological activity of the mature pollen grains of Betula verrucosa Ehrh. we investigated the protein-lipid composition and total antioxidant activity (TAA) of 10 samples from different habitats in the territory of Ukraine and the Slovak Republic. The collection sites are near highways and apartment blocks, as well as a nature reserve, forest and botanical garden. The protein content was determined by the Kjeldahl method. A chromatographic analysis of fatty acids from lipids was performed using a “Cvet 500” gas chromatograph, equipped with a flame-ionization detector in the isothermal mode. The bioactivity of aqueous, ethanol and methanol extracts of pollen grains was evaluated by the DPPH free radical scavenging method (2,2-diphenyl-1-picrylhydrazyl) by means spectrophotometry in vitro. The protein content of the pollen of B. verrucosa ranged from 17.9% to 25.6%, depending on the habitat. Unsaturated fatty acids were found in higher amounts than saturated fatty acids. The profile of fatty acids indicates a higher content of palmitic (33.9%), oleic (29.5%) and linoleic (27.8%) acids and a low content of arachidonic (0.4%) and pentadecanoic (0.8%) acids. We also established that silver birch pollen is characterized by high antioxidant activity. The measured value of TAA for aqueous pollen extracts was within 74.8–85.5%. For the ethanol extracts it was quantified within 60.3–95.0% and for the methanol extracts – 46.1–92.6%. The Tukey test was used to determine the differences between the means at a level of P < 0.05. A strong correlation coefficient (0.70) was defined between the protein content and the TAA of aqueous extracts. In general, the Ukrainian and Slovak samples of pollen differ in the fatty acid composition of lipids and aqueous and ethanol TAA extracts. Pollen of B. verrucosa should be used for diagnostic, therapeutic and prophylactic purposes as close as possible to the place of origin.

3-8

Authors: O. Maslovska, S. Hnatush

Desulfuromonas acetoxidans obtains energy for growth by the anaerobic oxidation of organic compounds with the carbon dioxide formation. It was found that ferrum and manganese are used as terminal electron acceptors in the processes of anaerobic respiration, such as dissimilative Fe3+- and Mn4+-reduction, carried out by these bacteria (Lovely, 1991). D. acetoxidans ІМV B-7384 can be used as anode biocatalyst in microbial fuel cell with high electron recovery through acetate oxidation to the electric current as a result of electron transfer to the anode or 3d-type transition metals, such as ferrum and manganese, in the process of their reduction. Investigation of biochemical changes of D. acetoxidans ІМV B-7384 under the influence of Fe (III) compounds is important for optimization of the process of bacterial electricity generation. ATP-hydrolase is located in cytoplasmic membrane, and its subunits are exposed to both the cytoplasm and the external environment. Therefore, the changes of that enzyme activity can be used as an indicator of various stress exposure. Presence of ferric iron ions in the bacterial growth medium could catalyze generation of organic reactive oxygen species, such as peroxyl (ROO-) and alkoxyl (RO-) radicals. Lipid peroxidation is one of the main reasons of cell damage and it’s following death under the influence of reactive oxygen metabolites. It is known that lipid peroxidation and membrane transport processes are somehow interrelated, but mechanisms of such interaction are still unidentified. In our previous researche we have shown the influence of ferric (III) citrate on the intensity of lipid peroxidation of D. аcetoxidans ІМV В-7384. Significant increase of the content of lipid peroxidation products (lipid hydroperoxides, conjugated dienes and malondialdehyde) in bacterial cells has been observed under the addition of ferric (III) citrate into the cultural medium. The increase of the concentration of lipid peroxidation products in bacterial cells confirms free radical mechanism of oxidation of polyunsaturated fatty acids. Thus, for fulfiling complete analyses of cell response against oxidative stress it was reasonable to investigate the influence of ferric (III) citrate on specific ATP-hydrolase activity, Na+, K+-ATP-hydrolase activity and Mg2+-ATP-hydrolase activity of D. acetoxidans ІМV В-7384. Bacteria were cultivated in the modified Postgaite C medium during four days under the anaerobic conditions and temperature +27°С with addition from 10 to 20 mM of ferric (III) citrate into the growth medium. Control samples didn’t contain investigated metal salt. Chosen concentrations of metal salt caused inhibition of bacterial growth by 20–50%. Activities of ATP-hydrolases were investigated as described. It was shown, that specific ATP-hydrolase activity of D. acetoxidans ІМV В-7384 is changing in dependance on duration of ferric (III) citrate exposure and concentration of the metal salt. Addition of the ferric (III) citrate in relatively low concentrations (10–12 mM) causes increasing of specific ATP-hydrolase activity of D. acetoxidans IMV B-7384 in comparison with control. Activity of investigated enzymes was inhibited under the increasing of metal salt concentration in bacterial growth medium. Increase of duration of D. acetoxidans IMV B-7384 cultivation causes decrease of ATP-hydrolase activity. Addition of ferric (III) citrate causes simultaneous increasing of Na+, K+-ATP-hydrolase activity and inhibition of Mg2+-ATP-hydrolase activity during four days of bacterial cultivation.

15-19

Authors: R. Kononenko

The state of world stocks of sturgeons is on the edge of catastrophe. These species are either extinct or under threat of extinction under human impacts. At the same time, there are enterprises, fish hatcheries, which deal with restoration and replenishment of natural stocks with of endangered fish species. One of such hatcheries is the sturgeon hatchery “Lebyazhy” (Astrakhan region, Russian Federation). The aim of the study was an analysis of piscicultural-biological features of the Russian sturgeon brood fish. During the study, which was conducted in April–May 2011, 34 Russian sturgeon females were used in two rounds, 17 individuals each. For stimulating gametes maturation, the Derzhavin’s physiological method was used. Caviar was obtained by stripping the eggs under strict hygienic and sanitary norms. Eggs fertilization with the semi-dry method used the male milt that bought at the “Raskat” LLC. Egg stickiness elimination was performed with the aid of talc and apparatuses for the egg stickiness elimination. Eggs incubation was performed in the “Osetr” apparatuses until yolk-sac larvae hatching. The domesticated fish were subjected to bonitation for determining their readiness for spawning. As a result of this bonitation, the brood fish were separated into two groups: first round of rearing works: females with mean weight of 34.8 kg and age of 9 years; second round: females with mean weight of 32.3 kg and the same age. Among injected females of the first round, 100% positive reaction for the stimulating injection was observed, but 95% – among females of the second round. Maturation time of females of both rounds varied from 25 to 30 hours. The maturation state of gametes of sturgeon females or males was determined based on samples obtained. 90.2 kg of eggs were obtained from females of the first round. At the same time, the maximum quantity was observed in the female of 50.5 kg – 9.2 kg of caviar, and the least quantity was obtained from the 27.8 kg female – 2.8 kg. On average, 5.3 kg of eggs were obtained per one female of the first round. The obtained quantity of eggs in one gram did not exceed 48 eggs that are considered to be within normal limits. 79.8 kg of eggs were obtained from females of the second round of rearing works that is 10.4 kg less in comparison with the results of the first round. On average, 5.0 kg of eggs were obtained from one female that is related to less mature fish used in the second tour. At the same time, the maximum quantity of eggs, 7.9 kg, was obtained from a 32.5 kg female, while the minimum quantity, 2.6 kg, from a 20.7 kg female. The obtained quantity of eggs in one gram did not exceed 44 eggs. Mean working fecundity of females of the first round was 198.2 thousand eggs, while it was somewhat less in the second round – 184.6 thousand eggs that did not exceed the normative values.

28-32

Authors: S.N. Kabuzenko, A.V. Omel’chenko, L.М. Mykhalska, V.V. Schwartau

The goal of this work is studying the accumulation and distribution of Na+ and K+ in maize hybrids of different salt tolerance under conditions of the chloride salinity. The new corn hybrid Veselka MV (salt-tolerant) and Odessa 375 MB (not salt-tolerant) were studied. The plants grown in salt-free chernozem soil are control. In the experiment, sodium chloride was dissolved in the irrigation water to form the salinity of test soils up to concentrations of 0.25, 0.5, 0.75, and 1.0% of ovendry weight. Soil moisture in the pots was maintained at 60% of the full field water capacity, the air temperature was +25…+27 °C, and the light – 10 klux. Plant samples were dried in the oven under 70°C. Then, the average sample of 10 specimens was thoroughly levigated in the porcelain pounder and dispersed in distilled water at 100°C. The ions were extracted, and the extracts were centrifuged for 20 min at 3000 rpm. The ions content in the cell sap was analysed. Plant samples (1 g) were incubated 10 min in chloroform, dried carefully with filter paper, and then the cell sap was squeezed. 1 ml of clear top layer of the cell sap was dissolved in 10 ml of distilled water. Ions content was determined by the atomic absorption spectrophotometer ("Karl Zeiss", Germany). Salt-tolerant maize hybrid Veselka MW (14 days age) is characterized by an increased content of Na+ in the root tissues in comparison with the above-ground parts. In Odessa 375 MB hybrid this regularity is less pronounced. With the increase of sodium chloride concentration in the soil the content of Na+ in the aerial parts of plants rises. That may be connected with the reduced role of a root barrier. The salt-tolerant hybrid has a higher content of Na+ in the roots as compared to the above-ground parts. The content of K+ was higher in the above-ground parts, which is more pronounced in the salt-tolerant hybrid Veselka MB. The decrease of K+ in cell sap of the root under saline conditions was most pronounced in the salt-sensitive hybrid Odessa 375 MB. The salt-tolerant hybrid Veselka MB is characterized by accumulation of Na+ mainly in the roots, but a higher content of K+ in the aerial part of the plant. For salt-tolerant hybrids are characterized by a higher ratio of K+ / Na+ in the above-ground parts of plants as compared to the not salt-tolerant hybrid.

38-42

Authors: D.Y. Reshetniak, V.V. Brygadyrenko

Development of the laboratory breeding technology of insects that damage agricultural crops can help in the pest control. Harpalus rufipes (De Geer, 1774) were fed by the following types of products: fresh frozen chicken and pork, cooked sausage "Doctor", cheese "Russian", boiled wheat and buckwheat. In the experiment, 56 adult specimens were kept individually in plastic containers during five days. In the same conditions 8 control test products were placed to determine the percentage of its mass loss due to desiccation. Keeping in a laboratory and feeding of H. rufipes (De Geer) by common human food is possible. Throughout the experiment, there were considerable variations in the consumption of food between individuals. Specimens of an average weight of 148.2 ± 45.6 mg consumed daily 71.4 ± 99.4 mg of fresh-frozen chicken and 77.2 ± 112.8 mg of the pork meat (48.1% and 52.1% of the body weight, respectively). Cheese and sausage were consumed in approximately the same amounts (73.1 ± 81.3 and 44.9 ± 66.0 mg daily, or 49.3% and 30.3% of the body weight, respectively). Low protein crop ration (wheat and buckwheat) provided the increase of the food intake (103.5 ± 108.5 and 79.8 ± 91.5 mg or 69.9% and 53.9% of the body weight, respectively). Chicken, pork meat and sausage contributed the weight gain, which amounts to about 0.43–0.82 mg (0.29–0.56% of initial body weight). A significant increase in body weight was observed for specimens feed by cheese (the weight gain was 3.14 ± 18.3 mg, 2.12%), by wheat (8.71 ± 21.33 mg, 5.87%), and buckwheat (2.73 ± 13.75 mg, 1.84% of the body weight). Starving individuals of H. rufipes that had an access to drinking water lost 2.6 ± 3.6 mg of the wet weight daily (1.76% of the body weight). That low rate of basal metabolism ensures the species survival during unfavourable parts of the seasons (summer drought, long autumn rains, etc.). Thus, the changes of body weights in imagoes of similar diets are evaluated. The sustainable keeping of H. rufipes (De Geer) culture in a laboratory needs the alternation of used food. That problem should be studied in details.

51-57

Authors: A.E. Pakhomov, O.M. Kunakh, A.V. Zhukov, Y.A. Baliuk

Study results of the spatial organisation of urbozem mesofauna are presented. We used the OMI-analysis methods. Field research was made in June, 1st, 2011 in the Botanical Garden of Dnipropetrovsk National University (DNU) (earlier – the territory of Y. Gagarin park, Dnipropetrovsk). The studied plot is situated at a distance of 220 m from the Building 1 of DNU and at a distance of 60 m from Y. Gagarin Avenue (the Southeast direction). The plot consists of 15 transects directed in a perpendicular manner in relation to the Avenue. Each transect is made of seven sample points. The distance between points is 2 m. The coordinates of lower left point have been taken as (0; 0). The plot represents artificial forest-park planting. The vegetation has typically wood mesotrophic mesophilic character (93.3% – silvants, 90.0% – mesotrophes, 81.7% – mesophiles). In each point the soil mesofauna was studied; temperature, electrical conductivity and soil penetration resistance, dead leaves layer and herbage height were measured. Soil-zoological test area had a size of 25 × 25 cm. We found that earthworms are numerous and saprohages are presented by 5 species. The Aporrectodea caliginosa trapezoides (Duges, 1828) is a dominant species. Along with that species an ecological group of endogeic earthworms is presented by A. rosea rosea (Savigny, 1826) and Octolasion lacteum (Oerley, 1885). An ecological diversity of earthworms is supplemented by epigeic Lumbricus rubellus (Hoffmeister, 1843) and anecic Octodrilus transpadanus (Rosa, 1884). The hygromorphs of earthworms range from ultrahygrophiles to mesophiles. The coenomorphic spectrum of earthworms is also rather wide and presented by “pratants”, “stepants”, “palludants” and “silvants”. The complex of earthworms in studied area is taxonomically and ecologically diverse. The ecological structure of soil animal community is presented by such dominant ecological groups as saprohages, pratants, hygrophiles, mesotrophocoenomorphs, and endogeic topomorphs. The measured soil characteristics have been shown to play an important role in structuring an ecological niche of mesopedobionts community. The basic trends in structure transformation of the soil mesofauna community are ecotone effect and edaphic properties determined by a vegetation cover.