Date palm biotechnology: Current status and prospective - an overview

The date palm is one of the most ancient plants, grows in the regions of Middle East, North Africa, South Sahel, East and South Africa. Its sexually propagation hampers propagation of true-to-type genotypes due to heterozygosity. The vegetative propagation is carried out with the offshoots, produced from axillary buds situated at the base of the trunk during the juvenile life of palm tree. Offshoot production is slow; their numbers are limited, laborious and can't meet the rapidly growing demand of varieties. To speed up the date palm genetic improvement, in vitro culture techniques could be handy; however, genotype influence limits the effective use. Bioreactor is being used for large-scale production of somatic embryos. Somaclonal variation is common among in vitro-derived date palm plants. However, it could broaden genetic variability together with mutagenesis; molecular markers AFLP used to identify variability and to select useful variants. Dwarf date palm hybrid was developed by embryo rescue by interspecific hybridization of Phoenix dactylifera and P. pusilla. In vitro germplasm conservation is done by cryopreservation for long-term storage. Alternatively, in vitro shoot cultures and plantlets are stored at 4°C for short term-storage. Micro-calli is produced from date palm protoplasts; Agrobacterium-mediated transformation succeeded in GUS gene expression in callus. Date palm genomics can distinguish multiple varieties and a specific region of the genome linked to gender. [PUBLICATION ABSTRACT]