Desiccation-Enhanced Maturation and Germination of Date Palm Somatic Embryos Derived from Cell Suspension Culture.

In vitro plant regeneration via somatic embryogenesis is a powerful tool for rapid, large-scale production of healthy true-to-type plants. This approach is suitable to preserve existing natural genetic variability and propagation of variability generated from genetic improvement programs, including crossing, somaclonal variation, mutagenesis, and somatic hybridization. This chapter outlines a simplified protocol for date palm regeneration via somatic embryogenesis induced in cell suspension cultures. In this protocol, culture medium composition is manipulated, including plant growth regulators and solid (addition of agar) and liquid media to achieve reduction of production cycle of somatic embryogenesis, which increases the multiplication rate of embryogenic callus and improves the quantity and quality of somatic embryos.

Microcalli Induction in Protoplasts Isolated from Embryogenic Callus of Date Palm.

Date palm (Phoenix dactylifera L.) production is severely hampered due to several pests and diseases. Biotechnological tools such as protoplast fusion appear as an alternative to ensure rapid genetic improvement and multiplication of this species. However, establishment of an effective system of plant regeneration from protoplasts culture is a prerequisite for date palm somatic hybridization. In this chapter, we describe an effective protocol to induce microcalli in protoplasts isolated from nodular callus of important Algerian date palm cultivars. In this protocol, the main factors influencing the isolation (i.e., enzymatic solution, mannitol concentration, duration, and mode of maceration) of protoplasts from the calli of Algerian date palm cultivars were optimized. Purified protoplasts were cultured on a semisolid medium supplemented with a hormonal balance of auxin and cytokinin to obtain microcalli formation.

A simplified Protocol to Induce Callogenesis in Protoplasts of Date Palm (Phoenix dactylifera L.) Cultivars.

BACKGROUND: In Algeria, date palm is currently confronted to the Bayoud disease. Biotechnological tools such as protoplastsfusion can appear as an alternative to ensure rapid multiplication and improvement of this species. OBJECTIVES: Callogenesis induction in protoplasts isolated from embryogenic callus of three date palm cultivars. MATERIALS AND METHODS: Some factors influencing the isolation and culture of protoplasts segregated from the calli of three date palm (Phoenix dactylifera L.) cultivars (Deglet Nour, Akerbouch and Degla Beida) were studied. Protoplasts of each cultivar were cultured on a semi-solid medium supplemented with various hormonal balances. RESULTS: Maceration with an enzymatic solution containing 1.5% cellulase and 1% macerozyme R10 in the presence of 0.5 M mannitol for more than 16 h with gentle agitation allows isolation of a great number of viable protoplasts. In addition, purification of protoplasts on a cushion of 21 or 25% sucrose was effective in cell debris removal and maximum recovery. The culture of isolated protoplasts on a semi-solidified Murashige and Skoog medium, with 0.3% agarose, 2 mg. L-1 2,4-D and 0.5 mg.L-1 BAP allowed good viable protoplast maintenance as well as cell wall regeneration. After more than two months of culture, cell divisions were still occurring and microcalli became visible to the naked eye, containing a large number of cells. CONCLUSIONS: The developed protocol can be useful for application of somatic hybridization to improve date palm cultivars.