Vol 21, No 2 (2019)

This article describes the vertical distribution of phytoplankton in a small urbanized lake Vosmerka (system Vasilevsky lakes, Samara region). The material was algological samples taken in the period from June to October 2013. The paper presents the results of the study of the vertical distribution of species richness of algae, value of quantitative development and species diversity.

In the article, the authors analyze the patterns of spatial variability of species richness, as well as the relative species richness of the life forms of vascular plants in the Middle Volga region. It is revealed that the shares of life forms in their spectra follow a geometric progression with the ratio d, characterizing the dominance of various life forms. Since the spectra of life forms depend on environmental conditions, the index d also depends on environmental factors. The equation of multiple regressions is calculated, showing the dependence of d on terrain features, climatic characteristics and soil types. Analysis of the obtained equation showed that the index d depends on the moisture supply of the region, average winter precipitation and temperatures. We have shown that the shares of the dominant life forms of vascular plants in the Middle Volga region - hemicryptophytes and annual grasses (therophytes) -are associated with the light level of the slopes. The authors note that the species richness as well as the indicator d does not depend on the light intensity.

The paper shows the influence of the type of nutrient medium and the concentration of growth regulators on the process of clonal micropropagation of polyploid varieties and forms (selection samples) obtained as a result of selection work based on three species Cranberry marsh (Vaccinium oxycoccos L.), Blueberry tall (Vaccinium corymbosum L.) and Lingonberry (Vaccinium vitis-idaea L.) of the genus Vaccinium L.

Cesium-137 is one of the most common radioactive isotopes that are released into the environment during nuclear accidents. Because of the relatively long half-life time, cesium-137 is still present in significant amounts in fresh waters and soils in the areas surrounding nuclear accident sites that occurred in the second half of the 20th and early 21st centuries. Many freshwater organisms have the ability to absorb cesium from the environment. It has been shown in experiments with the Lemna minor plants grown in the wild that this duckweed is one of the most efficient cesium accumulators among higher aquatic plants. In order to study duckweed accumulation capacities under the laboratory conditions, we grew aseptic L. minor plants on various cesium-containing culture media. The conditions for laboratory aseptic cultivation of two L. minor strains of different origin (Clone ID - 0008-14-LUG (Lm-14) and RDSC Clone 5500 (Lm-55)) were optimized. The accumulation of cesium ions by L. minor plants in a wide range of Cs+ concentrations in culture media in the presence of K+ ions in both low (mM) and high (mM) concentrations was studied. We also evaluated the viability of duckweed plants and measured the growth parameters of the plants under these growth conditions. The coefficients of Cs+ accumulation were determined and the effect of potassium ions on the accumulation of Cs+ was investigated. In aseptic conditions at micromolar K+ concentrations, the accumulation coefficients of Cs+ were found to be from 200 to 400. We also have shown that L. minor is able to accumulate cesium ions to the hyperaccumulation levels. These findings indicate a potential use of L. minor plants for remediation of water bodies contaminated with radioactive cesium. Our data on Cs+ accumulation in the presence of K+ both in low and high concentrations in the culture media also show that there is a competition between Cs+ and K+ ions for K+ -transporting proteins. We suggested that both the high affinity and the low affinity K+ transport systems may participate in the Cs+ absorption by duckweed plants, depending on the K+ and Cs+ concentrations in the medium, in particular a high affinity transporter of the HAK family or a K+-channel of the AKT shaker family.

To use the full potential of the new variety, taking into account its productivity and adaptability to the climatic conditions of the region, it is necessary to study the complex of agricultural techniques, primarily doses of mineral fertilizers. The results of the influence of fertilizers (1 - Control (without fertilizers), 2 - N15 P15 K15, 3 - N30 P30 K30, 4 - N60 P60 K60) on the productivity of oilseed flax were analyzed in Penza research Institute for the period 2015-2017. It is established that the variety is the Source with the introduction of nitrogen-phosphorus-potassium fertilizers in the dose of 60 kg D. V. the maximum seed productivity per hectare was 1.82 tons per hectare and the collection of oil and crude protein amounted to 709.7 and 436.7 kg/ha.The change in doses of mineral fertilizers did not have a significant impact on the oil and protein content in flax seeds and amounted to 43.47 - 43.89% and 24.27 - 30, 0%, respectively. The weight of 1000 seeds was in the range of 5.41-5.52 g. Application of nitrogen-phosphorus-potassium fertilizers norm 60 kg / ha provided an increase in the yield of flax straw by 26.7 % compared to the control.

The work purpose as a research of ekological-cenotic structure of plantings Acer negundo L. as indicator of transformation of communities on the former processed lands. Researches were conducted in inundated territories in suburbs of Kemerovo on which garden associations and personal plots were located more than 30 years ago. The middle-aged plantings of A. negundo having various crown density are chosen as objects of a research: not close, middle-close and high-close. Selection of the trial areas is carried out taking into account horizontal differentiation of space on internal, transitional and external zones of phytogenous fields. Geobotanical descriptions are carried out by standard methods, the taxonomical and ekological-cenotic structure of a ground cover is defined. In total 49 species of the higher plants which belong to 47 genus and 21 families are noted, zone distribution of types on a rank of families is established. The greatest specific abundance is noted for external zones of non-close plantings - 25 species, the smallest - for internal zones of high-close plantings. In non-close plantings recovery successions proceed on meadow type with a considerable delay in the transitional and the internal zones of trees where weed and invasive species are localized. In the middle-close plantings preservation of a projective covering of Poa angustifolia L. is noted up to 50%, but there is a considerable impoverishment of specific structure. In high-close plantings groups forest prevail and the ruderal species, however in addition of a live ground cover Humulus lupulus L. and Urtica dioica L. which not only are steady against joint growth under cover of A. negundo have major importance, but also supplement its role as transforming look that leads to formation of the simplified communities in a metastable state during vaguely long term.

The main objective of this article - to discuss, in low-woody areas of Central Volga area preservation of a biodiversity can benefit from the idea, following from the point of view of complex functioning of a biodiversity and ecosystems in the form of the formed structure, namely restoration ecology as from ecology of community, and an ecosystem in general. Especially protected natural territories are not common possible method for the conservation of biodiversity. An alternative is multi-purpose forest exploitation which includes preparation of forest products within the steady forest exploitation directed both to preservation of a biodiversity, and to ensuring benefits for local population and national economy. Preservation of natural forest ecosystems is the main function of the majority of forest areas. The concept of preservation of a biodiversity of management of natural and semi-natural types of phytocenosis covers a wide range of approaches.

The influence of temperature (30 and 37°С), pH (3.0; 4.5; 7.0; 9.0; 11.0) and concentration of NaCl (0 and 5%) on the morphological and cultural properties of the yeast S. cerevisiae DAW-3a was studied. It was shown that the characteristic feature of the strain was the spherical shape of the cells in all modes of cultivation. In all investigated variants, the minimum cell sizes are marked in acidic media at pH 3.0. Increasing the concentration of NaCl in the medium also led to a decrease in cell size, revealed the presence of granular cytoplasm, lipid inclusions were revealed. As a result of simultaneous exposure to NaCl and temperature over a wide range of pH values yeast in variants with alkaline and neutral pH of the medium tolerated salt stress more easily. Giant colonies of the yeast in the absence of salt at 30°C had the maximum size on the medium with pH 4.5, at elevated temperature 37°C - on medium with pH 3.0. Under conditions of salt stress, a significant decrease in the size of the colonies was observed at all pH and temperature values. The study of resistance of the yeast S. cerevisiae for extreme factors is important for the development of biotechnologies using yeast strains tolerant to various types of stress.

We have studied the variability and heterogeneity of the antioxidant status parameters in liver of different mouse-like rodents inhabiting areas of normal and high technogenic radioactive levels (the Komi Republic and the 30km exclusion zone around the Chernobyl nuclear power station, CNPS). In organisms of mammals, the ionizing radiation in small doses can form the reaction initiating development of general adaptation syndrome. Small mammals from the CNPS exclusion zone are identified for the increased variability and heterogeneity of antioxidation activity and composition of liver phospholipids in contrast with the mammals of the Ukhta field station. The obtained data evidence a strong misbalance of cell systems for animals from the accident zone being highly prominent in the first three years after the accident. The high variability and heterogeneity of biochemical liver parameters are fixed for animals inhabiting low- or mean-radioactively polluted areas. The antioxidant status changes in liver of mouse-like rodents within the Chernobyl zone depend on species and age of animals and time gone after the accident. The obtained data respond about different damage degrees of the antioxidant protection system in liver cells of the study animals. Against the high variability of phospholipids’ quantitative composition in liver of mouse-like rodents from the accident zone, we respond on the increase in the heterogeneity of parameters for animals caught at the same place. The mouse-like rodents from the radioactive zone demonstrate a relatively stable composition of liver phospholipids in 21 years after the accident evidencing a relatively stable condition of liver cell membranes. The high heterogeneity of response reactions and the high variability of the study liver parameters in organism of rodents from natural populations inhabiting elevated radiation areas specifically produced by low-dose ionizing radiation. These effects enlarge the potency and adaptation of organisms on the cell level to new radioactively polluted environmental conditions.

The article presents the results of the analysis of annual rings of Scots pine growing on the territory of the Volga Upland (Terengulsky District, Ulyanovsk Region). 10 old trees were investigated, with an average age of 157 years, a maximum of 182 years. On the basis of the chronologies of the growth of model trees of the trial area, one generalized tree-ring chronology of ULN (1837-2012) was obtained, the duration of the series was 176 years. In the constructed chronology, the years with the minimum increment were identified: 1839, 1891, 1921, 1943, 1984, 2010; with the maximum: 1854, 1857, 1886, 1919, 1951, 1990. The greatest rise in growth was observed in 1943-1952. Wavelet analysis in chronology revealed cycles with a period of 13 and 20 years. Correlation analysis showed a positive response of annual rings to June precipitation and January temperature. Thus, the pine of the Volga Upland of the Ulyanovsk Region is sensitive to the lack of precipitation in the summer period, so it has a large dendroclimatic potential, for example, for the reconstruction of droughts of the Volga region.