In vitro conservation of embryogenic cultures of date palm using osmotic mediated growth agents

This study was carried out to investigate the effect of mannitol, sorbitol and sucrose as osmotic agents on in vitro conservation of embryogenic cultures of date palm (Phoenix dactylifera, L.) Bartamoda and Sakkoty cultivars. Embryogenic cultures was obtained using MS medium supplemented with 10 mg/l 2,4-dichlorophenoxy acetic acid (2,4-D) and 3 mg/l isopentenyl adenine (2iP). Among the three types of osmotic substances used for slow growth conservation, sucrose at all concentrations gave the highest percentage of survival with Sakkoty cultivar. However, addition of 40 g/l or 60 g/l mannitol and 20 g/l sorbitol showed the highest percentage of survival percentage with Bartamoda cultivar. The different sucrose concentrations caused higher numbers of germinated embryos of the two cultivars compared with mannitol or sorbitol. Also, the number of germinated embryos was increased with increasing the storage periods till the ninth month. Genetic stability was determined using random amplified polymorphic DNA (RAPD) analysis. There were no clear genetic differences between the two osmotic agents used for preservation. The preserved cultures of Sakkoty cultivar gave the high percent of similarity while Bartamoda cultivar gave low percent of similarity. From the obtained results we can recommend using 40 g/l mannitol or 20 g/l sorbitol for in vitro preservation of Bartamoda cultivar of date palm and 20 g/l of sucrose for Sakkoty cultivar.