Abstract
Date palm is propagated by offshoot and tissue culture to produce plants that are true- to- type, which leads to decreased genetic diversity. Cryopreservation is used for the preservation of genetic resources of a wide range of plant species for short- to long-term storage. Callus induction was achieved for four cultivars (Ajwa, Khodary, Ruthana, and Sukary) on MS medium with 2,4-dichlorophenoxyacetic acid (2,4-D) (2.5 mg/l) and a-naphthaleneacetic acid (NAA) (5-7.5 mg/l) in combination with benzyladenine (BA) (0.5-1 mg/l). The calli were cryopreserved by encapsulation vitrification and dehydration methods. Survival and regeneration after cryopreservation in liquid nitrogen ranged from 51-57% and 29.66-41.33%, respectively, among the cultivars with encapsulation vitrification method. However, survival and regeneration was much low with dehydration method as compared to encapsulation vitrification and it was ranged from 16-24.66% and 27-33.66%, respectively. Genetic fidelity was assessed using SCoT markers in regenerated plantlets after cryopreservation and compared to mother plants as well as with tissue culture raised plantlets. Out of a total of 118 amplicons produced by 18 SCoT primers, 114 were monomorphic and the remaining were polymorphic. This low genetic variation indicates the clonal genetic stability of the regrown plantlets after cryopreservation.