Development of Cryopreservation Technique for Meristems of Syringa vulgaris L. Cultivars

Abstract

Cryopreservation is considered to be one of the most effective methods for long-term storage of plant genetic resources, particularly for ornamental species. However, there is a very little research on cryopreservation of lilacs. In this study, for the first time the cryopreservation protocol (a variation of a pregrowth-dehydration method) was successfully applied to two cultivars of Syringa vulgaris: ‘Aucubaefolia’ and ‘Polina Osipenko’. Explants of both cultivars were able to withstand the different steps of the protocol, and high survival and regrowth percentages were obtained after exposure to liquid nitrogen (67–100% and 63–88%, respectively). The current study is mainly focused on the preculture conditions of the applied method. Based on our results, we propose the use of paclobutrazol (PBZ) with the combination of 6-benzylaminopurine (BAP) and thidiazuron (TDZ) in the preculture medium for increasing explant tolerance to subsequent dehydration and freezing. During post-LN recovery, the explants appeared morphologically normal, and after 12–16 weeks after thawing, they were propagated and cultured as normal plantlets. Therefore, the reported method is effective for long-term storage of lilac meristems and could be used to create a cryobank of achievements in lilac breeding.

Plants, Cells, Algae, and Cyanobacteria In Vitro and Cryobank Collections at the Institute of Plant Physiology, Russian Academy of Sciences—A Platform for Research and Production Center

“…Some of these original innovations have been patented and used for cryopreservation of plant specimens belonging to diverse taxonomical groups and material types, including seeds, cell cultures, shoot meristems, protocorms, etc. (Table 3) [123,138,[142][143][144][145][146][147][148][149][150][151][152][153][154][155][156][157][158][159][160]. IPPRAS cryobank collections are unique in terms of the diversity of specimens and represented taxa and the long-term preservation of viable plant material in LN.…”

“…Our studies indicated no significant differences in the main characteristics between plant material of various types before and after cryopreservation [123,134,135,155,156] (Table 3). Plants regenerated from cryopreserved shoot tips were visually healthy without morphological abnormalities (Figures 6-9) [145,150,154,155]. Strawberry plants regenerated from cryopreserved shoot tips were successfully acclimatized and produced fruits (Figure 6a,b) [140,152,155].…”

“…For example, in addition to conventional methods, we have developed an effective cryopreservation technique for in vitro shoot meristems based on the fast freezing of specimens without using any toxic cryoprotectants or programmable equipment [135,151,153]. By utilizing this technique, we can dehydrate the shoot tips of strawberry and meristem tissues from in vitro plantlets of raspberry, blackberry, lilac, honeysuckle, and rowan tree under the flow of sterile air, frozen in LN, and recovered after several years of cryostorage (Figures 7-9) [123,135,145,151,153].…”

“…In conclusion, researchers at IPPRAS cryobank have developed an effective system for long-term preservation of the collections of vegetatively propagated plant material that integrated the method of in vitro culture, cryopreservation, and ex vitro cultivation [135,152,153,155]. Using this system, the cryobank can store strains for the long term and effectively use numerous clones of ornamental, berry, and fruit plants for several decades [123,134,135,145]. Between 1977 and 2022, the IPPRAS cryobank was enriched with more than 1000 specimens (cell cultures, shoot meristems, and seeds) of different plant material belonging to 457 species of higher plants from 74 families [122,123,134,135,153].…”