The present work is devoted to investigation of the possibility to apply methods of Marker-Assisted Selection (MAS) to introgression the SalTol QTL into genotypes of elite Russian varieties of rice. It was shown that microsatellite markers Rm493, may be effectively used to control transfer the SalTol QTL genes into Russian populations of rice. Based on the highly productive variety "Novator", we obtained the lines Nov-129 and Nov-148 carrying loci SalTol in homozygous state. The lines Nov-129 and Nov-148 are used as an improved salt tolerance donor source to obtain hybrids tolerance to salinity.

The purpose of this research by the way of investigating the molecular genetic structure of a highly variable fungal phytopathogen Pyricularia oryzae Cav., to determine effective genes for the development of a strategy for immunogenetic protection against rice blast in conditions of epiphytotic development of the disease in the south of Russia, which would combine high efficacy with both environmental friendliness and resource and energy saving, to ensure country's food security. The knowledge of local pathotype diversity of Pyricularia oryzae Cav. and the (a)virulence genes in rice-growing regions of Russia may allow the prediction of new races and its interaction in local agro-ecology. The identification of virulence gene may become an indispensable theoretical basis for the development of genetic sources with long-lasting resistance to rice blast. Based on molecular and genetic approaches, the genetic structure and biodiversity of the phytopathogenic fungus Pyricularia oryzae Cav. in the south of Russia were considered. The monitoring was studied and it isolated 57 strains of the pathogen from the damaged herbal material collected from the fields in eight agro-ecological rice-growing regions of the Krasnodar Region (Russian Federation): Krasnoarmeysky, Kalininsky, Krymsky, Abinsky, Temryuksky, Seversky, Slavyansky districts, Krasnodar, Rostov Region (Russian Federation)-Proletarsky district and the Republic of Adygea (Russian Federation). A multiplex PCR technique was applied on the basis of fragment analysis to identify the virulent fungal isolates. 33 fungal genotypes with unique genetic profiles were identified among the studied races of Pyricularia oryzae Cav. Their DNA profiles were created. The studied isolates of the pathogen of rice blast were classified using morphological and microbiology cultural features. Based on the phytopathological test using differentiation rice varieties, the quantitative and qualitative composition of (a)virulence genes in fungal races was established. Effective genes for pathogen resistance, which are recommended for breeding programs for the development of rice varieties resistant to rice blast, were identified in the south of Russia.

Rice (Oryza sativa L.) plants were subjected to NaCl stress within 35 days. The shoot dry weight, root dry weight, total survival percentage and contents of inorganic ions in dry samples of stressed plants were measured to identify the physiological adaptive mechanisms by which rice plants at vegetative stage tolerate salt stresses. Laboratory testing of the 10 rice cultivars showed that the salt concentration for the treatment is especially significant for assessment of the relationship between ion accumulation and salt tolerance. Salt treatment strongly stimulated accumulations of Na + , Na + /K + ratio, Clin shoot and root and reduced K + , NO 3 contents in both organs under 1.2% NaCl stress condition, but not always under 0.6% NaCl concentration. It was shown significantly negative correlation (p<0.5) between the Na + content and dry weight of shoot and root under 1.2% NaCl stress condition. Also, was founded significantly negative impact (p<0.5) of Clions on biomass growth and survival rice plants and positive relationship (p<0.5) among the root dry weight and K + , NO 3 content under the high NaCl concentration (1.2% NaCl). So, in addition to Na + , the contributions of Clto abiotic stresses of rice should not be ignored.

Grain productivity of rice is significantly reduced by dangerous disease – blast. Therefore, the development of resistant high yielding rice varieties with the Pi group of genes is important. Use of molecular markers linked with the loci of resistance significantly optimizes the breeding process. The purpose of the research is to develop rice lines combining 2-6 loci of resistance to blast: Pi-1, Pi-2, Pi-33, Pi-ta, Pi-b, Pi-40 by molecular marking. Materials and Methods. As donors of resistance genes foreign samples were used, recipient – Russian varieties. In the studies we used micro-satellites markers and PCR analysis. Results. In the first stage of the research as a result of hybridization domestic lines with genes Pi-l, Pi-2, Pi-33 were obtained. At the second stage – hybrids with all 3 genes were developed. In the third stage genes Pi-b and Pi-ta and on the fourth – Pi-40 were introduced. Conclusion. As a result, rice genotypes, combining 6 loci of blast resistance were developed with use of marker assisted selection.

The article presents the results of the conducted analysis of research works about the effect of size of flag leaves and awns on winter wheat productivity. The genetic potential of the variety, which can be realized on the basis of its biologic characteristics largely influences on its productivity. Productivity is a complex trait that is controlled by a complex genetic system closely connected with many factors of environment. The size and duration of assimilation surface are the most important components of biologic and agricultural yield of wheat. Many researchers showed that the amount and duration of photosynthesis by leaf surface are the main factors limiting productivity in the definite conditions of growing, and the size of leaf surface correlates with grain productivity. Photosynthetic parts of winter wheat include not only leaves, but also stems, heads, awns, etc. The conducted analysis of the literature showed that there is no consensus on the effect of flag leaves on wheat yield formation. Therefore it’s necessary to fulfill the study and evaluation of the part of flag leaves and awns in the formation of winter soft wheat productivity in the Rostov region.