Relevance. The use of modern biotechnological methods in breeding, namely the doubled haploid technology and marker-assisted selection, can significantly reduce the time for creating pure lines with valuable properties. Fusarium wilt is one of the economically important diseases of white cabbage. Therefore, the development of a MAS method for selecting doubled haploids resistant to fusarium wilt would allow fast selection of resistant pure lines. Moreover, the resistance testing can be done at any plant developmental stage.Materials and methods. The response of hybrids Gertsoginya F1, Poisk 2018 F1 (resistant samples, the originator – the Agrofirm “Poisk”) and Slava 1305 (susceptible sample, the originator – Federal Scientific Vegetable Center) towards Fusarium oxysporum f. sp. conglutinans infection was determined by evaluating their growth on the inoculated soil. To test the efficiency of the FocBNUf/r marker to the polymorphic region of the FocBo1 gene, the markers were tested on resistant and susceptible genotypes. Then the markers were applied to analyze 60 doubled haploids of 12 different genotypes.Results. It was demonstrated that the FocBNUf/r marker effectively differentiated resistant and susceptible samples. Doubled haploids were obtained from 12 different breeding samples for FocBNUf/r marker-based selection of fusarium wilt resistant plants. PCR testing of doubled haploids for fusarium resistance allowed us to select 6.7-100% of plants with the fusarium resistance gene in a homozygous state in 8 genotypes. 4 genotypes of doubled haploids that did not carry the resistance gene were eliminated from the breeding program.Conclusion. The FocBNUf/r marker effectively identified resistant and susceptible samples, as well as differentiates homozygous and heterozygous plants. FocBNUf/r marker was used to select resistant doubled haploids of white cabbage at the seedling stage. Thus, it was possible not only to accelerate the production of pure lines by obtaining doubled haploids, but also to accelerate the selection of valuable samples carrying the gene of resistance to fusarium, which makes it possible to avoid the labor-intensive selection of resistant lines on inoculated soil.

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.

Relevance. Lettuce (Latin: Lactúca satíva) is a species of annual herbaceous plant in the genus Lettuce of the Asteraceae family. As a vegetable crop, it is cultivated everywhere in the world, and its hydroponic cultivation technology has received special development in recent years. One of the common pathogens of lettuce is Pseudomonas cichorii, causing bacterial diseases of several important cultivated plants. In this regard, the study of the occurrence of this pathogen is important.Material and methodology. The study was conducted on the basis of the Department of Agrobiotechnology of the ATI of RUDN University. The samples were provided by a commercial manufacturer of lettuce grown on a flow-through hydroponic line under conditions of minimal microbial contamination. The study of phytopathogenic bacteria includes a number of stages: isolation of bacteria on semi-selective culture media and obtaining a pure culture of bacteria; setting a test for pathogenicity (virulence); studying the phenotypic properties of bacteria; determining the taxonomic position of the isolated strains by molecular methods. All studies were conducted in accordance with the standard methods of identification of phytopathogenic bacteria.Results. As a result of the work, the distribution of the species Pseudomonas cichorii in the hydroponic culture of lettuce in the Russian Federation was confirmed. Although, according to the EPPO database, P. cichorii was first described in Russia in 1965 by microbiological methods, but isolated bacteria are not available in microbiological collections to confirm this conclusion with appropriate diagnostic methods. Twelve isolates of P. cichoriiwere studied by a biochemical and phytopathological tests, and four isolates (01, 04, 06, and 12) that showed the greatest aggressiveness on host plants and tobacco leaves were identified by DNA sequencing of the 16S rRNA gene fragment. The obtained DNA fragments showed a high similarity (99-100%) with the sequences of P. cichoriifrom the Genebank. Evaluation of the virulence of the isolated isolates on a number of other cultivated plants, and the uniformity of their biochemical characteristics showed that they represent a group of bacteria specialized in lettuce.

Relevance. Plants of potato varieties are carriers of viral pathogens in a latent form. These viruses can be transmitted to clonal progeny of the carriers. The system of virus-free seed production facilitates the elimination of the viruses in seed potatoes and preserves the high productivity of potato varieties. The research goal was to develop a scheme for virus elimination in potato using biotechnological methods and to introduce this scheme in the production of virus-free tubers under the conditions of Primorsky krai.Material and methods. New promising variety Moryak (breeding number Pri-08-11-1), which was created in FSBSI “FSC of Agricultural Biotechnology of the Far East named after A.K. Chaiki”, was used as the research object. The mean yield of the new genotype is 34.1 t/ha, the potential yield is 40.1 t/ha. The dry matter content is 18.13-23.85%, the starch content is 12.10-17.24%, and the content of vitamin C is 17.46-23.12 mg/100 g. This variety has a high keeping quality of tubers (92.2-94.4%) and resistance to excessive soil moisture. Tissue culture and chemotherapy in combination with ribavirin (a concentration of 0.02-0.03%) and chitosan (0.01-0.1%) were used for virus elimination. Sprouts from the original tubers and plantlets were tested by EIA and qPCR for latent infection (PVX, PVY, PVA, PVS, PVM, PLRV).Results. A sequential increase in the concentration of ribavirin (from 0.02 to 0.03%) and chitosan (from 0.01 to 0.1%) and their alternation in different passages proved to be an effective method for virus elimination in plantlets. As the result of the research, the new scheme for the elimination of the most economically important potato viruses was developed and introduced, and virus-free seed material was obtained.