Izvestiya of Saratov University.
ISSN 1816-9775 (Print)
ISSN 2541-8971 (Online)


Биология

The Coefficient of Replenishment for the Commercial Stock of Catfish from the Release of Its Juvenile by Weighing Batch of 2 Grams in the Reservoirs of the Volga-Caspian Fishery Basin

The practical value of the coefficient of commercial replenishment of fish stocks, due to the variety of its use in different areas of fisheries research, design work, restoration activities, and management decisions was highlighted. For many species of fish there is no information on the indicator under consideration. Catfish, one of the valuable commercial species, is included in this category.

Modern Cadastre of Vectors and Other Reservoirs of Tularemia Microbe Found in Tularemia Foci of Different Types, Situated in the Territory of Russia

At the present stage of the studies only Ixodidae ticks can be classed by the types of foci, being the main blood-sucking vectors of the tularemia agent. Other blood-sucking arthropods, considering the species abundance and wide-spread occurrence and certain habitat versatility, can be tularemia vectors in several or even in all types of foci. These are the following: primarily, gamaside and argasid ticks, as well as bloodsucking insects.

Morphogenesis and Reproductive Ability Monocarpic Escape Hosta sieboldiana (Hook.) Engl. (Hostaceae) in the Conditions of the Novosibirsk Region

The results of studying the morphogenesis of monocarpic escape during the seasonal development of Hosta sieboldiana are presented. It is shown that organ-forming processes of generative organs occur in the spring-summer vegetation of the shoot. Generative shoot is formed at 75–76 of days to flowering. Established, that the cone of increase of the escape differentiates intrarenal II to VIII stages of organogenesis. The flowers are laid in the acropolis direction. Duration of flowering was 25–38 days, fruiting 29–30 days.

Changes in the Permeability of the Blood-Brain Barrier in the Development of Alzheimer’s Disease in Mice

In our study on mice with an injection model of Alzheimer’s disease (AD), beta-amyloid detection in the brain tissue was evaluated using immunohistochemistry and confocal analysis. An accumulation of toxic protein was shown in different areas of the brain, predominantly in the cortex and in the hippocamp (place of beta-amyloid injection). Neurofunctional tests were conducted to confirm the development of AD.

Peculiarities of Spatial Distribution of the Bottom Fauna in the River Kan (Tributary of the Middle Yenisei, Krasnoyarsk Region)

In the rivers of the Yenisei basin, benthic invertebrates play a major role in feeding most valuable Siberian fish species. This report presents advanced material on zoobenthos of the river Kan (one of the major tributaries of the Yenisei in its middle course). Litho-psammo-rheophilic biocenosis of benthic invertebrates was the most developed, 99 species and forms were recorded there. The total number of zoobenthos was formed from mayflies, caddisflies and chironomids; biomass – from caddisflies and mayflies.

The Additional Data about Spring Beetles Fauna (Insecta: Coleoptera) of the Natural Monument «Rasskazan’ Lake» (Saratov Province)

The present work is a continuation of the inventory of the coleopterofauna of the water-terrestrial ecotones of the nature monument «Rasskazan’ Lake» Balashov district of Saratov province, which began in 2017. The study concerned the spring fauna of the period of occurrence of the Khoper river in low water after floods and the beginning of the stagnation of the lake water level.

New Associations of Steppe Vegetation in National Park «Khvalynsky»

The article considers the issue of studying the steppe vegetation of the Khvalynsky National Park from the standpoint of ecologophytocenotic and ecologo-floristic approaches to the classification of vegetation. New associations Alysso tortuosi-Artemisietum salsoloidis Lysenko ass. nov. hoc loco, Euphorbio glareosae-Festucetum valesiacae ass. nov. hoc loco, Artemisio marschallianae-Stipetum pennatae Lysenko ass. nov. hoc loco, Astragalo varii-Bromopsietum inermis Lysenko ass. nov. hoc loco, Astragalo albicaulis-Stipetum lessingianae Lysenko ass. nov.

Ecological Features of the Development of Rooted Systems of Vegetable Cultures at Different Level of Moisture

The article presents the results of studying the dynamics of the formation of the root and above-ground mass of spring soft wheat, virgin and fallow cenoses under the conditions of 2012 and 2018. The dynamics of the placement of the root system of cultivated plants in the grain-pair crop rotation over the vegetation phases was revealed. It was shown that spring wheat forms the secondary root system during the growing season only in favorable meteorological conditions, mainly within the 0–50 cm layer (74%).

The New Experience Use of Malaise Trap for the Study of the Beetles Fauna (Insecta: Coleoptera) of National Park «Khvalynsky» (Saratov Oblast)

The article describes the new experience of the long-term use of the Malaise trap (tent trap) for the season 2018–2019 on the territory of the National Park «Khvalynsky» (Saratov province). During this period, 44 species of beetles belonging to 19 families were recorded 6 species: Leiodes obesa (Schmidt, 1841), Philonthus concinnus (Gravenhorst, 1802), Mordellistena humeralis (Linnaeus, 1758), M. intersecta Emery, 1876, M. purpureonigrans Ermisch, 1963 and Scraptia fuscula P. W. J. Muller, 1821 were recorded in the fauna of Saratov oblast for the first time.

Economic and Biological Characteristics of the New Generation of Winter Wheat Varieties

The aim of the work is a comparative assessment of economic and biological characteristics (yield and crop structure elements, winter hardiness, morphological structure of the stem) of the new generation of winter soft wheat varieties. The studies were conducted in 2017–2019 in the conditions of the South-East of the Central black earth region. The object of research is winter wheat, represented by varieties Steppe 135, Basalt, Chernozem 115, Chernozem 130 and Basalt 2, created at different times of selection work.

Pages