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


Биология

Fragmentation of Quercetin and Naringenin and Photoinduced Processes under Laser Desorption/Ionization Conditions

We found that under laser desorption and ionization conditions, quercetin, belonging to the flavonol family, undergoes a decay, which occurs through a photoinduced reaction followed by dimerization of the forming biradical and by the subsequent fragmentation of the dimer. Naringenin, belonging to the flavonone family, also undergoes similar fragmentation, but owing to the lack of conjugation in the C ring, the forming biradical particle is not capable of further dimerization in the same way as observed for quercetin because of its low stability.

Type Specimens of Alchemilla L., Corispermum L., Koeleria Pers., Onosma L. Kept in the Sprygin Herbarium of Penza State University (PKM)

Sprygin Herbarium of Penza State University – the largest sci- entific Botanical collection with the international acronym of the PKM, founded in 1894 on the initiative of the largest naturalist Ivan Sprygin. In the collections of the Penza Herbarium contains about 170 000 herbarium sheets of vascular plants, mossy plants, algae, lichens and fungi, of which over 30 authentic samples. Since 2009, the Herbarium is the electronic cataloguing of the collection. Results of revision on the type of genus Alchemilla L. (Rosaceae), Corispermum L.

On the Study of the Genus Alchemilla L. (Rosaceae) in the Penza Region

As a result of critical revision, 37 species of the genus Alchemilla were revealed in the Penza region (Russia): A. acutiloba Opiz, A. atrifolia Zamelis, A. baltica G. Sam. ex Juz., A. breviloba H. Lindb., A. cheirochlora Juz., А. conglobata H. Lindb., А. cymatophylla Juz., А. decalvans Juz., А. exilis Juz., А. glabricaulis H. Lindb., А. hebescens Juz., A. heptagona Juz., A. hians Juz., А. hirsuticaulis H. Lindb., A. homoeophylla Juz., А. leiophylla Juz., А. lessingiana Juz., А. lindbergiana Juz., A. litwinowii Juz., A. macrescens Juz., А. micans Buser, A.

Screening of Genus Azospirillum for their Ability to Produce Extracellular Lignin-Peroxidase and the Degradation of Model Lignin Compounds and Azo Dyes

Lignin peroxidase is one of the main enzymes of fungi decomposers of wood, that is capable to many non-specific oxidation of aromatic and polycyclic compounds. By the beginning of our research there were virtually no data of the bacteria’s ability to produce the lignin peroxidase. Rather recently lignin peroxidase activity was detected by us in the washouts from the surface of the bacterial cells and in intracellular extracts of bacteria from genus Azospirillum.

The Influence of Aqueous Dispersions of Metal Nanoparticles on the Adhesive Properties of the Standard and Clinical Strains of Staphylococcus aureus

The initial stage of interaction of infectious agents with micro-organisms cells is the process of adhesion. So there is a need to develop methods that reduce the adhesive activity of microorganisms. Aim: to study the impact of water and water dialyzed dispersion of silver and copper nanoparticles obtained by biochemical synthesis, on the adhesive properties of the standard and clinical strains of S. aureus. Using standard techniques for cells of S.

Morphologigal Characteristics of Seeds of Some Iris L. Species in Saratov Region

The research presents the results of morphological study of seeds belong to five species of Iris L.: I. aphylla L., I. halophila Pall., I. pseudacorus L. I. pumila L., I. sibirica L. which existed in Saratov region and cultivated in the botanical gardens of national research of Saratov state university, previously named «N. G. Chernyshevsky».

Light Influence on Morphogenesis Wheat

In work results of research morphogenesis wheat are presented at presence or absence of the light factor. Influence of light on growth of all leaf shoot, activity of a cone of increase and growth of germinal root system of a seedling of wheat is established. In the presence of the light factor growth epicotyl begins with the moment of the termination of growth coleoptile. Growth epicotyl occurs synchronously to growth of a sheath of 1st leaf. In the absence of light growth coleoptile and epicotyl proceeds and after end of growth of a plate and a sheath of 1st leaf.

Antagonistic Activity of Bacterial Association of Apple Shoots Against Phytopathogenic Fungi

Microbial associations on surfaces and internal environment on shoots of apple sorts Golden Delicious, Wealthy and Berkutovka with symptoms of fungal infections were studied. 195 strains of epiphytic and endophytic bacteria, of which 8 strains had marked antagonistic activity against phytopathogenic fungi Alternaria alternaria, Aspergillus tubiengensis, Fusarium incarnatum equiseti, Fusarium tricinctum and Phoma fungicola were isolated. Antagonistic bacterial strains are identified as Bacillus amyloliquefaciens SA77, B. badius SA68, B. gibsonii SA104, B.

The Female Gametophyte Structure Features of Two Nicotiana Tabacum L. Mutant Lines

The embryo sacs structure in the two mutant lines of Nicotiana tabacum L. was investigated. The various disturbances in the megagametopyte structure were detected. In the М-3 line the gametophyte mutation suppresses the nucleus mitotic activity and cell walls initiation in embryo sacs. These disturbances lead to the formation of low-nuclear coenocytic or cellular gametophytes. In М-2 line the cellular gametophytes with increased number of cells and nucleus was dominated. The reason of this phenomenon is an increase of mitosis number during a gametophytogenesis.

Acoustic Communication Signals between Ants of the Genus Formica (Hymenoptera: Formicidae) and Myrmecophilous Beetles of the Genus Scydmaenus (Coleoptera: Staphylinidae)

In the article was given the mathematical approaches to classification and clustering of data of acoustic signals in communication between myrmecophilic beetles (Scydmaenus hellwigii) and ants (Formica rufa). For the first time for these species were used a cluster analysis which revealed four clusters, each of them has its own command from the beetle to the ant. Each command was defined by specific ranges of dominant frequencies and a range of medium amplitudes (the values of the parameters R).

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