Cryopreservation of Smirnovia iranica (Sabeti) Seeds and Evaluation of Cryopreserved Seeds under Laboratory, Greenhouse and Natural Habitat Conditions

Smirnovia iranica (Sabeti) synonym: Smirnovia turkestana (Bunge) is a deciduous perennial bushy species of the Fabaceae (Papilionaceae) family. The species grow on sand dunes of desert areas, having a deep vertical root and very long horizontal or lateral roots. They have an important role in natural vegetation of desert and sand dune stabilization. Limited growing areas, grazing due to good palatability, and foliage quality of the plant have put this species under threat. Seed preservation under cryogenic conditions at -196ºC is an important approach to conserve seeds for a long period. In this study, seeds of the S. iranica were collected from natural habitats of the plants and three pre-cryopreservation treatments including PVS2, Desiccation, and 30%Glycerol were applied before transferring the seeds into liquid nitrogen (LN) at -196ºC for 1 week, 1 month, and 1 year (in 2015). Subsequently, the seeds were removed from the liquid nitrogen, imposed to heat shock and evaluated under laboratory, greenhouse and natural habitat conditions. The cryopreserved seeds of various cryopreservation periods germinated normally under laboratory and greenhouse conditions. In laboratory conditions, there were no significant differences between periods of seed storage in cryogenic conditions for seed germination trait. The highest seed germination percent (84%) was observed in the desiccation pre-cryopreservation treatment. In pre-cryopreservation treatments as well as cryogenic storage periods under greenhouse conditions, seed germination and seedling establishment were significantly different. In natural habitat, the cryopreserved seeds germinate and grow to normal seedlings and plants. The results showed that S. iranica seeds can be successfully stored in cryogenic conditions for a long period.