ON THE POSSIBILITY OF LONG-TERM SEED STORAGE OF THREE SPECIES OF ANNUAL CULTIVATED PLANTS IN SEED BANKS

One of the effective forms of ex situ preservation of plant biological diversity is seed banks. The International Council of Botanical Gardens has proposed two temperature regimes for seed storage: low positive temperatures (+5 о C) and shallow freezing (–20 о C). The most valuable genetic resources are recommended to be stored in conditions of deep seeds freezing in liquid nitrogen (–196 о C) or in vapors above it (about –160 о C). A comparative study of the effect of different seed storage regimes (at + 5 о C, –20 о C and under deep freezing conditions at –196 о C) of annual, economically important species: flax – Linum usitatissimum L., foxtail millet – Setaria italica (L.) Beauv. and lacy phacelia – Phacelia tanacetifolia Benth. on their viability and plant development in the field has been conducted. Freezing of these species’ seeds did not have a significant effect on laboratory and field germination, as well as did not cause any non-viable, ugly seedlings or plants. The plants went through a full cycle of development and formed full-fledged seeds. Freezing of lacy phacelia seeds did not significantly affect the number of flowers in private inflorescences. But the number of inflorescences on one specimen was significantly greater than that of control plants, both axillary and apical. Consequently, the seed productivity of plants obtained from frozen seeds may be higher than that of control plants. The root system of this species from seeds after cryopreservation was the most developed. Cryopreservation is the most promising method of storing seeds of the studied species, as it provides longer periods of preserving their viability.