No abstract

The viability of pollen of 5 collectible varieties of Russian plum of the Pushkinskiye and Pavlovskiye VIR Laboratories SPB before and after cryopreservation was studied. It was found that a significant factor for the level of pollen viability is “variety” (p=0.07), the factors “cryopreservation” (p=0.457), “year” (p=0.221), as well as the interaction of the factors “variety× cryopreservation” (p=0.172), were not significant at the p<0.05 level of significance. For long-term storage of Russian plum pollen in liquid nitrogen, the year of pollen collection is not a significant factor. For most genotypes, no negative impact of cryoсonservation on pollen viability was revealed. The varieties ‘Aureus’, 'Podarok Sankt-Peterburgu’ and ‘Exotica’ after cryopreservation for 1 year showed a tendency to increase the pollen viability indicators.

Successful application of the CRISPR/Cas genome editing system to various crops largely depends on the correct choice of target genes that may be purposefully changed to improve yield, quality, and resistance to biotic and abiotic stressors. The objective of this work was systematizing and cataloguing the information on the confirmed target genes for crop improvement. The latest systematic review was presented on peer-reviewed scientific papers (indexed in the Scopus database) published before August 17, 2019. The present study covers the period from August 18, 2019 to March 15, 2022. The search according to the given algorithm revealed 2090 publications, and their analysis showed that only 685 original papers contained the results of gene editing for 28 crops (the search included 56 crops). A significant part of these publications described the application of genome editing to target genes previously identified in similar works or the studies were associated with reverse genetics, while only 136 publications contained data on editing new target genes whose modification was aimed at improving plant traits important for breeding. The total number of target genes in cultivated plants that were edited to improve properties of breeding value over the entire period of the CRISPR/Cas system application was 287. A detailed analysis of the editing of new target genes is presented in this review. The studies were most often aimed at increasing plant productivity and disease resistance as well as improving the properties of plant materials. Observations are made whether it was possible to obtain stable transformants at the time of publication and whether the editing technique was applied to non-model cultivars. For a number of crops, however, the range of modified cultivars was significantly expanded, specifically for wheat, rice, soybean, tomato, potato, rapeseed, grapevine, and maize. In a vast majority of cases, agrobacterium-mediated transformation was used to deliver the editing construct; less often it was bioballistics, protoplast transfection or haploinducers. The desired change in traits was most often achieved by gene knockout. In some cases, knockdown and nucleotide substitutions were applied. The base-editing and prime-editing approaches have increasingly been used to make nucleotide substitutions in crop genes. The emergence of a convenient CRISPR/Cas editing system helped to significantly intensify the development of molecular genetics specific to many crop species.

Background. VIR’s potato collection is one of the oldest and richest; however, it is constantly exposed to viruses that negatively affect useful agronomic properties of tubers. Close monitoring of the phytosanitary state of potato accessions helps to select the most effective method of therapy for subsequent healing of infected plants and obtaining high-quality planting material.Materials and methods. The research was aimed at improving the health of 18 varieties of Solanum tuberosum L. from the VIR collection. Testing for the presence of viruses was based on the ICA and RTPCR techniques, and the consequent healing was performed using the methods of meristem culture and cryotherapy.Results and conclusions. During the field test of potato plants, PVX, PVS and PVA were found to be the most common viruses. PSTVd was completely absent in all tested accessions. The effectiveness of in vitro healing of potato plants from viruses was assesses using meristem culture. The percentage of healed plants was 0% for PVS, 0% for PVX, 33.4% for PVA, 50% for PLRV, 72.3% for PVY, and 83.4% for PVM. Healing with meristem culture was shown to be the most effective against PVY and PVM. While assessing the effectiveness of post-cryogenic restoration of potato microplants, the level of post-cryogenic regeneration of the shoot tips in potato microplants was determined at 22.3% on average for a sample. The minimum was observed in k-16762 ‘Sagita N’ (5%), and the maximum in k-1378 ‘Marta’ (41.7%). Analysis of the effectiveness of potato recovery from viruses by in vitro cryotherapy showed that the percentage of recovered plants was 100% for PVY, 100% for PVA, 88.9% for PVM, 77.8% for PVS, 44.4% for PVX. Thus, the techniques of apical meristem culture and cryotherapy proved to be effective against PVY, PVA and PVM viruses. However, in the case of multiple infections, it is necessary to combine elements of different healing protocols to increase the effectiveness of the healing procedure.

In the northwestern agro-ecological region of the country, with its shortened plant growing season, plant resistance to various diseases, early harvests, and problems of their storage, a promising and effective intervention is the use of growth stimulants. To enhance growth, plants were treated with an amino acid preparation (glycine) at dosage rates 20, 40, 60, 80, 100 and 120 mg/l. The reference sample was treated with water. The experimental samples exceeded the reference in mean fruit weight; the greatest increase of fruit weight and dry matter content was observed in the 5th sample (fruit weight: 0.79 g, dry matter content: 10.2%). Sample No. 3 contained the highest amount of sugars, with the preparation's dosage 40 mg/l: 9.56%, which was higher than the reference by 2.44% (sample No. 1). This excess refers to monosaccharides and disaccharides. The content of malic, citric, oxalic and tartaric acids in all experimental samples was higher than in the reference; the best results were shown by sample No. 6, with the dosage 100 mg/l.