Using Vitrification–Dehydration Method as a New Protocol for In-vitro Cryopreservation of Date Palm Shoot Tip Cultivars

Abstract

This study was conducted to develop an in vitro method for the short-term conservation of the planting materials of date palm (Phoenix dactylifera). The conservation of the genetic resources of date palm species and germplasm represented by the cryopreservation of biological material, such as shoot tips of date palm dropped in LN (Liquid Nitrogen) at low temperatures, is a safe method. The main objective of this study was the collection and in vitro germplasm preservation of the date palm cultivars, and this study evaluated the in vitro preservation and genetic stability of date palm shoot tip explants using dimethyl sulfoxide (DMSO) in the medium for long-term storage. Shoot tip explants of about 2-3 cm in length were excised from in vitro cultures and were transferred to preservation media. The results showed that the highest rates of survival (80%) and recovery (75%) were observed with 1.2 M sucrose. To determine the effect of vitrification on freezing tolerances, cultures were exposed to a solution that dissolved the glaze for 60-80 minutes. The maximum survival rate obtained with exposed cultures was 85%. RAPD (randomly amplified polymorphic DNA) was used to explain the differences in the genetic characteristics of cryogenic tissue cultures and non-cryogenic tissues of date palm. Both were similar to the germinated date palm in the open field. Finally, the cryopreserved plants were able to adapt to free-living conditions after acclimatization, All aspects will contribute to the improvement of the currently available techniques for the in vitro germplasm conservation of date palms.