Биология

There are 17 nestbird species at the Volga River riverside’s precipices and slopes of right-bank ravines in the south of Saratov district in 1996–2007 were found. Spatial location of the species along the riversides is determined by sedimentary layers interchange: sands of senoman, chalks of thuron, flasks and marls of santon, flasks of palaeogene, clays of neogene. 

Basic regularities of abundance changing in different local relief formations in recreation forest are discovered. Main factors stipulated similarities and differences of bird population dynamics in plateau and gully-ravine habitats were studied on the ground of all-the-year-round absolut bird census. 

The information on a history of creation of the Herbarium of SSU is given. The structure of funds of the Herbarium (the basic departments, nominal collections) is considered. The modern condition of the Herbarium is reflected. On the basis of a database of the Herbarium the quantitative information on one of the largest families of the Bottom Volga region – Сyperaceae is given.  

We studied the gender particularities in renal hypertension development and the dynamics of cardiovascular effects of immobilization stress in normotensive and hypertensive male and female rats. Also, we investigated the cardiovascular sensitivity to adrenaline and propranolol in normotensive and hypertensive males and females. We revealed the stronger sympathetic control of cardiovascular activity in females vs. males that may be partly responsible for the greater cardiovascular stress resistance in females compared with males. 

Microbial ecological systems of Aphis pomi Deg. digestive tract in territory of the Saratov region was studied. 23 bacteria species belonging to 15 genera was revealed. Curtobacterium flacumfaciens causing diseases at plants was among them.

Azospirillum can directly or indirectly stimulate growth of plants and improve yield of at least several plant species. Structural distinctions LPS O-antigen determinate antigen variations Azospirillum species. Thirty eight strains of Azospirillum were screening. The fact that most research strains demonstrated cross-reactions with model strains underlie the division into three serotypes, including eight serovariants. Seven strains demonstrated cross-reactions only with genus-specific antibodies and have been separated into individual group.

The effects of toxin producing entheropathogenic Escherichia coli on blood microcirculation in ventral mesentery of white rats were studied. The increasing of blood flow velocity in capillaries has been observed under the influence of toxins in the course of short intervals.

The renovations to the ecological formulas of 36 species were made on the basis of 117 phytocoenotic descriptions in Saratov region. The entering of 8 new species in ecological scales of L.G. Ramenskiy et al (1956) are proposed/ In this paper the enumeration of additional species and their ecological formulas are adduced.

In a course of investigation of seed productivity under the pollenless regime of flowering in 154 natural populations of 98 species of 46 the Asteraceae genera from Saratov province gametophytic apomixis has been discovered in populations of 24 species from 14 genera. For the first time this mode of reproduction has bean revealed in 7 genera and 16 species of the family (Hieracium largum, Pilosella echioides, Tragopogon dubius, Lactuca serriola, Scorzonera ensifolia, Chondrilla latifolia. Ch.

The habitation of three species of the Cobitidae family (Misgurnus fossilis, Cobitis taenia, and Cobitis melanoleuca) in the reservoirs of the Northern Lower-Volga region is confirmed. That of two species of the family (Cobitis rossomeridionalis and Sabanejewia aurata) in the region is hypothesized.