This review is devoted to the description of chemical peculiarities of industrial oil crops cultivated (or prospective for cultivation) in Russia, which are stored in the VIR collection. Different crops have similar fatty acids biosynthesis pathways, but each species has its own individualities in the chemical composition of the oil and its genetic control. The diversity of oil crop chemical composition opens the possibility of its multipurpose utilization practically in all industrial segments. Sunflower, rapeseed, flax, mustard, camelina and safflower are cultivated in Russia as oil crops. Castor beans, perilla, lallemantia and noog are not cultivated on an industrial scale, but have original oil properties and are prospective for future cultivation. Hemp and poppy seeds contain oil valuable for food, but they are not widespread. Cotton and peanut oils are prospective for industrial purposes when early, already created varieties of these crops will be cultivated in Russia. Oil properties depend on the ratio of its basic fatty acids: saturated (stearic, palmitic) and unsaturated (oleic, linoleic, linolenic). As a rule, lauric, myristic and palmitoleic acids are determined in minor quantities. The oil of Brassicaceae crops also includes arachidic, eicosenoic, eicosadienoic, behenic, erucic and lignoceric acids. Fatty acids accumulation is influenced by growing conditions, though it has strict genetic control.

Background. Linseed solin varieties were created for nutrition, but the effect of oil fatty acid (FA) composition on other characters is not clear. Materials and methods. Using 6 inbreeding generations from 26 heterogeneous flax accessions were generated 19 high (HL), 7 medium (ML) and 14 low linolenic (LL) lines. For each lines contents of 5 basic FA: palmitic, stearic, oleic (OLE), linoleic (LIO) and linolenic (LIN); the ratio LIO/LIN, oil iodine number, vegetative period (VP) phases and plants size were evaluated. Development of CAPS marker for LuFAD3A gene was performed using idtdna.com. Sequencing of LIN genes sites was done in the Centre MCT SPBGU and Eurogen. Results. ANOVA showed significant differences HL, ML and LL groups for PAL, OLE, LIO, LIN, LIO/LIN, IOD. Considerable decrease of LIN, causes asymmetric changes in FA ratio and correlations between them and other traits. Factor analysis revealed the influence of two factors. The first one divided lines according to their LIN level and characters associated with it, the second one according to the VP and OLE. LIN synthesis is controlled by two complementary genes LuFAD3A and LuFAD3B. Sequencing of LuFAD3A gene 1 exon of 6 lines revealed a mutation (G255 A255), resulting in formation of stop codon. Developed developed CAPS-marker confirmed the homozygosity of hybrids between LL (gc-391) and HL lines (gc-65, 109, 121). Descendants of hybrid between gc-109 and gc-391 ripened 8-10 days earlier than gc-391. CAPS markers of LuFAD3B gene revealed differences between HL, ML, LL lines. Sequencing of this gene first exon and the beginning of the second one in 3 lines (1HL, 2LL) showed that this method reveals a mutation in the second restriction site, located in the 2 exon (C6 T6), and causing the replacement Hys Tyr. Conclusion. Lines from GC have wide variability of FA and other agronomic characters, combination of which will expand the cultivation of solin.

Flax is one of the oldest oil crops, but only since the end of the twentieth century nutritional use of its whole seeds and flour has been resumed. This crop has been evaluated for its oil fatty acid composition, content of sterols and tocopherols, carbohydrate composition of mucilage, but a comprehensive study has never been carried out, so the aim of the work was to identify differences in the metabolomic profiles of flax lines contrasting in color and size of seeds. The biochemical composition of seeds from 16 lines of the sixth generation of inbreeding was tested using gas chromatography coupled with mass spectrometry. In total, more than 90 compounds related to sugars (78% of the identified substances), free fatty acids (13%), polyatomic alcohols (5%), heterocyclic compounds, free amino acids, phytosterols and organic acids (no more than 2.5% in total) were identified. Statistical analyses revealed six main factors. The first is a factor of sugar content; the second one affects most of organic acids, as well as some free fatty acids, not related to reserve ones, the third factor is related to compounds that play a certain role in the formation of “storage” substances and resistance to stress, the fourth factor is influencing free polar amino acids, some organic and free fatty acids, the fifth one is a factor of phenolic compounds, the sixth factor combined substances not included in the first five groups. Factor analysis made it possible to differentiate all 16 lines, 10 of which occupied a separate position by one or two factors. Interestingly, the first two factors with the highest loads (20 and 15% of the total variability, respectively) showed a separate position of the gc-432 line, which differed from the others, not only by chemical composition, but also by the phenotype of the seeds, while gc-159 differed from the rest ones by the complex of organic acids and other substances taking about 1% of the extracted substances of the seed. Thus, the analysis of metabolomic profiles is promising for a comprehensive assessment of the VIR flax genetic collection, which has wide biochemical diversity.

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.

The review summarizes diverse knowledge about the problem ofLinum usitatissimumL. response on photoperiod. Within this species, high genetic variability of the photosensitivity degree and influence of photoperiod on different plants characters were discovered. It was shown that in flax, earliness of flowering in long daylight is not strictly related to the low photosensitivity, and late genotypes with low photosensitivity can be found. In short daylight, various plant characters of different genotypes can be stable or display different reactions: increase or decrease their values. Also, the degree of photosensitivity does not have stable correlations with agronomic characters.

Background. There are strict requirements for a modern flax cultivar. It must have a whole set of valuable characters, including rust resistance.Materials and methods. The flax collection of 2485 accessions held by VIR was evaluated using artificial provocative infection.Results. Almost all domestic and foreign accessions and varieties collected before 1957 were highly or extremely susceptible to rust. Five Russian kryazhs1 and cv. ‘GDS-3’ developed at VIR were found to retain rust resistance up to the present moment. Lines derived from them and from three foreign varieties, with an identified number of the original effective R genes, were submitted to breeders. Nineteen donors with a set of economically useful traits, analogous to cvs. ‘Orshansky 2’ and ‘Prizyv 81’ and carrying the same genes, were produced and distributed to breeders. The VIR collection holds 10 donors of rust resistance with high fiber content developed at the All-Russian Research Institute of Flax. Some donors of resistance to other diseases released by the same Institute also possess high rust resistance, thus forming a rich stock of source material. The first cultivar relatively resistant to rust (‘L-1120’) was released in 1951. Possessing polygenic resistance, it was also resistant to Fusarium wilt and lodging, so it was widely used for breeding other cultivars with similar characteristics. As their cultivation expanded, the harvest losses caused by rust dropped. The first rust-resistant cultivar with oligogenic resistance (‘Tomsky 16’) appeared in 1990. By now, many cultivars protected by R genes of rust resistance have been developed. They combine this trait with resistance to Fusarium and lodging, high yield, and high fiber content. Flax rust incidence is not a problem anymore.Conclusion. Plant breeders have at their disposal a rich stock of source material preserved in the VIR collection to produce resistant flax cultivars. The use of rust resistance donors in hybridization cannot disrupt the most important properties of a cultivar.