In Vitro Conservation of Date Palm Somatic Embryos Using Growth-Retardant Conditions

In vitro conservation is carried out to maintain disease-free genetic materials, in a small area, protected against pests, insects, soil problems (alkaline, acidic, excess salinity, lack of organic matter, too dry, or too wet), climatic changes, and high-multiplication potential. A requirement of successful in vitro conservation is that the plants can be regenerated into complete plants rapidly when desired. The current work describes in vitro propagation and conservation techniques employing slow-growth conditions of date palm somatic embryo cultures. Clusters of somatic embryos resulting from an indirect micropropagation protocol are conserved in MS culture medium supplemented with an osmotic agent (sucrose at 90 g/L) combined with a growth-retardant hormone (abscisic acid) at 2 mg/L incubated at low temperature (18 °C) and low light intensity (10 μmol/m²/s). The survival and plant recovery rates are recorded after 10 months. Date palm somatic embryo clusters can be conserved for up to 10 months without subculture with high survival rates. Successfully conserved somatic embryos multiply and germinate to regenerate plants with well-developed shoots and roots, which survive acclimatization and field transfer.