No 3 (2024)

Histological events occurring in the calluses of Lavandula angustifolia Mill. at the initial stages of in vitro culture (1 passage) were described for the first time. It was found that the non-morphogenic callus is mainly represented by parenchymal tissue with few morphogenetic foci, mostly degenerated. In morphogenic calluses the morphogenesis pathways such as de novo organogenesis and indirect in vitro somatic embryogenesis have been identified and multiple developing morphogenetic foci have been noted also. The question of the realization of the pluri- and totipotency properties of callus cells in vitro is discussed. The histological data can be used in choosing the direction of application of regenerants obtained from calluses of this valuable essential oil and medicinal plant in various cell technologies.

The results of a phenology study of 78 species of perennial plants from biomorphological groups of chamaephytes, hemicryptophytes and geophytes over a 20-year period (1996—2015) are discussed. Against the background of air temperature and precipitation changes of the warm season in Novosibirsk, the timing shift in phenological events have been analyzed using calculated linear trends. It is found that the trends for species groups are multidirectional and vary significantly in magnitude. At the same time, most of the shifts in phenology are due not to trends, but to the interannual variability of climatic indicators.

We performed a parasitological survey of helminths of 398 waterfowl specimens from an ecologically unique territory of southern Karelia (North-West Russia). This is the first study of species composition and infection of birds that are definitive hosts of Bilharziella polonica have been obtained. The trematoda of Bilharziella polonica has been recorded only in seven species of birds — mallard, teal, garganey, goldeneye, tufted duck, shoveler, and red-necked grebe. The species of B. polonica has been recorded of red-necked grebe for the North-West of Russia for the first time. The role of infected birds of Bilharziella polonica in support of schistosomiasis, a disease that causes morbidity for causing human cercarial dermatitis or swimmer’s itch, were shown. We present data that life cycle of Bilharziella polonica is successfully implemented in the conditions of Karelia.

In this work, the cryoprotective properties of dipeptide L-carnosine (β-alanyl-L-histidine) were studied on slices of the olfactory cortex of the brain of rats. Changes in the activity of N-methyl-D-aspartate receptors were analyzed as the most vulnerable to the effect of cryopreservation (CP), for this purpose, extracellular NMDA potentials were recorded. Slices were incubated with L-carnosine (20 mM) in the medium and frozen at a slow rate (0.1°C/min) down to –10°C and after CS (30 days) they were heated at the same rate (0.1°C/min) to +37°C. The effectiveness of cryoprotection of L-carnosine was determined by changes in the amplitudes of NMDA potentials after CP compared to before CP. The dipeptide restored the pH of the freezing medium 6.9 (without L-carnosine) to the optimum pH 7.3—7.4, promoted dehydration of free water from slices after CP, inhibited the development of glutamate excitotoxicity in slices. The data obtained prove that L-carnosine exhibits the properties of a non-toxic effective cryoprotector in the nervous tissue of warm-blooded non-hibernating animals.

Using the patch-clamp method in the whole-cell configuration, it was shownthat external potassium ions play an important role in the regulation of calcium-activated chloride currents. A clear dependence of the amplitude of chloride currents on changes in the concentration of external potassium is shown. Changes in concentration of sodium, magnesium and calcium ions from membrane outside have no so significant effect, like outside potassium ions. The effect of potassium on the amplitudes of chloride currents is significantly greater than the effect it has on other cell ionic currents — sodium, potassium, cation. There is reason to believe that a change in the amplitudes of chloride currents contributes to the pathophysiological processes characteristic of hypokalemia and hyperkalemia.

As a result of comprehensive researches in the Lake Arbakalir and the Spring Charsky Goryachi klyuch during the growing season in 2021, the physical and chemical parameters of water, species and phytocenotic diversity of vegetation were studied. 56 taxa from 7 divisions of which 31 species belong to flowering plants, 22 species to macroalgae, one species in each to bryophytes, horsetails and lycophytes were identified in the flora of water bodies. Two species are included in the Red Book, both at the federal and regional levels. Two species are classified as relict. The structure of the flora contains species of three ecotypes, of which 38 species (67.9 %) belong to true aquatic plants. 18 associations from 12 formations were identified in the syntaxonomic structure of aquatic and coastal aquatic vegetation. Based on factor analysis, the main factors influencing the distribution of phytocenoses are water temperature, pH, mineralization, and main cation, anion and nutrient contents.

The article studies the mass of fine (up to 2 mm in diameter) roots of woody species and the patterns of their distribution across the soil profile in post-agricultural forest communities in the middle taiga of Karelia, Russia. Forest site characteristics were determined in sampling plots established following conventional procedures. The root mass was determined by the soil monolith method. Analysis showed that young communities developed a greater mass of fine roots compared to older stands. The total root occupation of the top mineral layer of soil was higher than in the forest floor. In most cases, both coniferous and deciduous roots prevailed in mineral soil layer. The relationship between fine root mass and basal area was identified.