Cryopreservation provides long-term storage of the gene pool of potato varieties in cryobanks at extremely low temperatures. Currently, droplet vitrification is the most widely used method for cryopreservation of potato varieties, which is constantly improving to increase the regeneration rates of the stored plant material. Different modifications of this method are used in the world’s leading potato genebanks. This paper presents the results of studying the effect of cultivation conditions after plunging into liquid nitrogen and thawing of shoots tips and axillary buds of in vitro plants on their postcryogenic recovery. The droplet-vitrification method modified at VIR was used for cryopreservation. The factor “prolonged dark incubation of explants” did not have a significant effect on the frequency of post-cryogenic regeneration of the studied varieties except for one variety (Krepysh), for which a significant increase in the regeneration rate was observed for the shoot tips cultivated in the darkness compared to the cultivation under the photoperiod 16/8 hours (light/darkness). The frequency of post-cryogenic regeneration of shoot tips was higher than that of the axillary buds for all varieties; however, these differences were significant (p < 0.05) only in two cases: for the variety Udacha (a photoperiod of 16/8 hours) and for the variety Krepysh (the dark incubation). The results of two-factor analysis of variance indicate that there is no effect of interaction of factor 1 (prolonged dark incubation) and factor 2 (explant type) on the ability of varieties to post-cryogenic recovery. Taking into account the obtained results, the further cryopreservation of an extended subset of 9 varieties was carried out using shoot tips, which, after freezing-thawing, were cultivated under the photoperiod of 16/8 hours. The frequency of post-cryogenic regeneration of these varieties varied from 30 to 60 %. A significant effect of genotype on postcryogenic recovery has been established. The ability of varieties to regenerate shoots after freezing and thawing was not related to the values of morphogenic indices of in vitro plants. The age of the meriklons (2–4 years) did not significantly affect either the morphogenic indices or the frequency of post-cryogenic regeneration.

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It was found that genotypes can be divided into three groups: with accelerated, medium and late morphogenesis during the morphological structure formation. The outcomes are based on the in vitro study of the ontogenesis of 35 potato varieties. Intensive regenerative ability is inherent to potato varieties which formed regenerants during 20–25 days. Varieties with medium morphogenesis were regenerated during 30–35 days. Microplants which formed 4–6 internodes during 40 or more days were characterized by late morphogenesis. The data obtained revealed that the maturity group did not affect the in vitro formative process. Assignment of a variety to a specific morphological group allows a differentiated approach to be applied to its maintenance in the genetic collection and its use in the in vitro replication process.

The main biological feature of potato varieties is vegetative reproduction. This mode of reproduction can be associated with problems due to the physiological ageing of the crop and the accumulation of specific pathogens causing reduced tuber yields. In order to avoid these problems, potato seed production widely uses modern biotechnological methods. The use of meristemic technologies allows preserving the identity of the biomaterial in the process of maintaining the potato collection in vitro, but even under these conditions there is a threat that modifications of individual economically valuable traits may get fixed. In potato varieties, such non-heritable deviations manifest themselves in the form of a shift in phenophases and the period of tubers ripening. The use of modern high-tech methods of varietal resources storage implemented on the basis of biotechnological approaches, makes it possible to maintain high quality of biomaterial. At the same time, mobility and practicality remain the main criteria for the effectiveness of different storage methods, depending on the extent to which they can be used in practice. In this review, the collection of varieties at Russian Potato Research Center is used as an example for considering the main stages of the formation and functioning of a modern Bank of Healthy Potato Varieties (BHPV), which supplies various regions of the Russian Federation with high-quality phytopathogen-free potato varieties.

The article studied the passage of interstage periods and the yield formation of tubers of 93 potato varieties with different ripening periods. The selection of base clones was carried out in northern and southern conditions of Primorsky District in Arkhangelsk Oblast and the highlands of the North Caucasus at an altitude of 2 300–2 500 m above sea level. The growth, development and formation of tubers was significantly influenced by the length of day in the northern region and long sunshine hours in the highlands. The multiplication coefficient of plants in the highlands increased by 1.2–2.3 times compared to the northern region, while the highest increase was observed in late-ripening varieties. The weight of tubers of the early and mid-early ripening varieties was exceeded by 1.9–2.7 times compared with the northern region; the weight of the later period varieties was exceeded by 2.9–3.1 times.