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Andrey Pavlov, Janka Nôžková, Miroslava Šavrtková, Inna Matvienko and Nina Brutch

Abstract

Plants of 13 fibre flax varieties were tested for their photosensitivity and differences of stems structure while grown in long and short daylight. It was detected that seven varieties did not change time of flowering in short 12 hours daylight in comparison with long 19 hours daylight. The extended diversity of fibre flax reactions on photoperiod changes and its relative independence of photosensitivity degree were found. Also, weak but significant correlation was found between photosensitivity coefficient and the degree of leaves number increase (r = 0.57). At the same time photo insensitive variety Belosnezhka improved leaves number up to 34%. Numbers of fibre bundles, their individual and total area on the stem cross section were not changed or reduced. Width, height, perimeter and shape of fibre bundles on a cross sections changed multidirectional. The areas of stem, its wooden part and cavity on a cross section showed no significant differences between plants grown in long and short day conditions. Evaluated flax characters were not strictly correlated with each other except those indicating the structure of fibre bundles. For breeding it is important that their relationships are not strongly influenced by the environment.

Open access

Tamaz Kalabegishvili, Ivane Murusidze, Elena Kirkesali, Alexander Rcheulishvili, Ereri Ginturi, Nana Kuchava, Nanuli Bagdavadze, Eteri Gelagutashvili, Marina V. Frontasyeva, Inga Zinicovscaia, Sergey S. Pavlov and Andrey Y Dmitriev

Abstract

The synthesis of gold and silver nanoparticles by the blue-green algae Spirulina platensis for medical purposes was studied. A complex of optical and analytical methods was used in order to characterize produced nanoparticles. It was shown that the extracellular formation of metal nanoparticles of spherical shape with sizes in the range between 8 and 40 nm (the average size of 20-30 nm) takes place. The characteristics of gold and silver nanoparticles in the Spirulina biomass were compared. The role of biosorption processes in the synthesis of nanoparticles was estimated by using equilibrium dialysis. A positive influence of sonication on the process of microbial synthesis and yield of nanoparticles were demonstrated. The neutron activation analysis and the atomic absorption spectrometry were applied for characterizing the dynamics of gold and silver nanoparticles formation in the Spirulina platensis biomass. The neutron activation analysis was used for studying the elemental content of the Spirulina platensis biomass.

Open access

Katarína Ražná, Janka Nôžková, Lucia Hlavačková, Nina Brutch, Elizaveta Porokhovinova, Tatiana Shelenga and Andrey Pavlov

Abstract

MicroRNAs (miRNAs) are a class of non-coding RNAs about 20-24 nucleotides long. They play an important role in the gene regulation at the post-transcriptional level. They affect the plant genome response to environmental stress. The miRNA-based molecular markers is type of functional markers reported in very few plants. However, the information connected to the evaluation of genotypes by this type of markers within a single species is missing. Considering the stability, polymorphism, functionality and transferability potential of miRNA-based markers, the research was conducted to apply selected types of them (miR156b, miR408a and the combined type of miR156b/miR408a) for the genotyping analysis of eight flax genotypes of different origin together with the morphology analyses. A total of 145 miRNA loci were identified, of which 19 were unique. The highest numbers of miRNA loci (57) and unique fragments (9) as well as the highest percentage of polymorphism and the extent of polymerase chain reaction (PCR) amplification of miRNA fragments have been observed with the combination of miR156b-F and miR408-F markers. By means of the miRNA markers has been recorded the unique profile of the miRNA loci for individual accessions. The morphology study has shown that the genotypes are the same in the expression of selected morphological traits despite the different use and different places of origin. However, we have identified an interface between some of morphological traits and miRNA-based markers for genotyping the genetic resources of flax. By mutually linking these two types of markers, we were able to determine unique genotypes of flax.