In vitro Propagation of Date Palm Cultivars Magdoul and Safwai through Somatic Embryogenesis

The success of genetic conservation, cloning and possible genetic transformation requires an effective micropropagation protocol in vitro. For date palm (Phoenix dactylifera L.), there seems to be a lot of reported genotypic variation influencing optimum in vitro protocols. Two different cultivars of date palm Safawi and Magdoul were investigated to establish efficient protocol for callus induction, somatic embryogenesis, shoot proliffaration in vitro and plant acclimization ex vitro. The highest value of callus induction and relative water content (RWC) was reached at 25.0 mg L-1 2, 4-D and 5.0 mg L-1 2iP; 10 mg L-1 2, 4-D and 8.0 mg L-1 2iP for cvs. Safawi and Magdoul, respectively. The highest percentage of callus producing somatic embryos were 92.25% and 96.18% obtained on MS medium fortified with 6.0 mg L-1 2iP with 1.0 or 3.0 mg L-1 NAA for cvs. Safawi and Magdoul, respectively. High root formation occured on 2 and/or 2.5 mg L-1 NAA alone or with of 0.5 mg L-1 IBA. Regenerated plantlets were successfully acclimatized ex vitro with a 55-70% survival rate. The present article gives an update of the current approaches of date palm micropropagation with emphasis on the plant regeneration through somatic embryogenesis. It highlights key factors that influence in vitro differentiation and evaluated somatic embryos from embryogenic lines established from two cultivars with respect to their ability to germinate and be converted into plantlets

Cryopreservation of Embryogenic Callus of Date Palm (Phoenix dactylifera) cv. Magdoul through Encapsulation-Dehydration Technology

To overcome the genetic deterioration and the extinction of date palm genotypes and species as result of environmental challenges, it has become necessary to develop techniques that allow the remaining genetic resources to be persevered under in-vitro conditions for long period without a substantial decline in the vitality, genetic stability and low survival. The development of an effective cryopreservation method for date palm (cv. Magdoul) via an encapsulation-dehydration method for long term conservation was researched in this study. Embryogenic callus, obtained from shoot tip culture, was used as explants and exposed to different concentration of sucrose (0.0, 0.5, 0.75, 1.0 and 1.5 M) combined with dehydration time (0–10 days) and different drying time (1–10 h). It was found that using sucrose at 0.75 M was more effective compared with using 1.0 and 1.5 M. Among the drying time tested, 4 h gave the best result for survival. The interaction treatment between sucrose, dehydration and moisture content (MC) was studies. After different periods of time in liquid nitrogen, the greatest values of survival (74.4%) and regrowth (71.25%) after 6 weeks of storage were obtained when 0.75 M sucrose for three days followed by 4 h dehydration period with a 39.50% MC was applied. The present results indicated that encapsulation-dehydration can be applied as a simple and effective protocol to a diverse range of cv. Magdoul genetic resources using embryogenic calli. © 2020 Friends Science Publisher