Increase of plants resistance to adverse environmental factors is considered to be the basic factor affecting the production of sustainable yields and high quality of agricultural crops. Anomalously high and low temperatures, water logging and drought, bacterial infections and herbivore attack compose significant risk factors during cultivation of different agricultural crops including tomatoes. In last decades great attention is paid to the possibility of plants protection against oxidative stress via biofortification with selenium. Effect of selenium biofortification in adverse ecological conditions of the Chechen republic (high humidity and low temperature) on yield and biochemical characteristics of two tomatoes varieties (Utro, Krasny Velican) was investigated. Dose of 4 mg Se/sq. m in triple processing during vegetation resulted in 18.9-89.9% increase of fruit yield depending on the cultivar tolerance to cladosporium. For the first time the possibility of selenium utilization in protection of plants against cladosporium was demonstrated. Biofortification of plants with selenium resulted in 1,36-1.41 increase of ascorbic acid content, 1.1 times – of carbohydrates, 1.13- 1.22 times – of titratable acidity, 1.9-1.23 time – of betacarotene, 1.55-1.36 times – of licopene. Taste index of tomato fruit also increased by 10%. 16 Fold fortification level of tomato fruit provides 22-29 % from the adequate selenium consumption level with 300 g of the product.

Relevance. The purpose of this work is to create new discrete competitive tomato genotypes based on modern biotechnological approaches with increased resistance to the tobacco mosaic virus, economically valuable traits and adapted to the soil and climatic conditions of cultivation in the southern regions of the Russian Federation.Methods. At the first stage of the study, SSR markers taken from literature sources were tested [1;2] and PCR conditions were optimized for the identification of target Tm genes (Tm2a, Tm22, providing resistance to tobacco mosaic virus at the tissue level) in the breeding material available in the department of vegetable and potato growing.Results. Two informative molecular markers Tms 37 and UMD 2060 were selected, which reveal the allelic difference between resistant and susceptible samples. Hybridization of FMS tomato lines with samples having the desired genes of interest in the genotype for obtaining tomato lines resistant to TMV was carried out. Seeds of paternal forms - donors of target genes were obtained for their further use in breeding work. The scientific novelty lies in the study of the discrete genetic material of Solanumlycopersicum, used in the breeding process, and preserving its functions in a new genetic environment.

Preservation of tomatoes takes place by appropriate preparation of raw materials, packing in a container and sealing it with subsequent heat treatment. In the course of our studies on the suitability  of new varieties  for canning, we noted that all varieties  reacted differently  to heat treatment. For example, the forward variety, which has high taste qualities, had a sugar-acid index of 8,44,  compared to 7,04-7,51  in other varieties,  the tasting commission was estimated at 3,1-4,6 points, which is lower than other varieties, due to cracking of the skin of the fetus. After a year of storage, the sugar and acid index, depending on the variant, was 9,18-9,93, which indicates high taste qualities of the fruit. It was noted that the higher flavor qualities, regardless of the storage time, were in option 2.  For the varieties  Festive, Carat and Forward, the best was option 3. By the end of storage, it was 11,82 for the Festive variety, 10,51  for the variety Karat and 11,98  from Forward. According to the sugar-acid index of all the varieties studied, we distinguished Forward. We found that the sugar-acid index was higher than the taste, both before and after canning, in all varieties,  indicating  their high taste qualities. A higher score was given to variants 1 (control), 3 and 4. In variant 5, a sharper smell of garlic was noted.

Qualitative and quantitative evaluation of tomatoes carote-noid composition is considered to be the basis of tomato selection. Among known methods of identification and carotenoid content determination thing layer chromatography (TLC) is characterized by inexpensive, quick and availab-le method of analysis. Comparison of individual tomato carotenoid content data obtained using wellknown empirical formulas and based of TLC separation on chromatoraphic paper was achieved. Empirical formulas for the determination of lycopene and beta-carotene concentrations were shown to give high variations in beta-carotene content and decreased values of total carotenoids concentration values. Developed conditions of chromatographic separation and identification of selected carotenoids are based on different polarity of individual pigments and specific absorption spectra of the latter. Method of thin layer chromatography may serve as a quick and effective method for quality evaluation of tomato fruit of different color and determination of beta-carotene, ζ-carotene, neurosporene, lycopene and lutein content.