IMPORTANCE OF PROTOPLAST CULTURE IN THE GENETIC IMPROVEMENT OF DATE PALM (PHOENIX DACTYLIFERA L.)

Totipotent protoplasts are considered as a very important tool for plant genetic improvement. Protoplast were isolated from embryogenic calli in both ‘Deglet nour’ and ‘Takerboucht’ genotypes, calli were initiated from shoot apical tips of young offshoots of adult female trees growing in the field under natural conditions.
Embryogenic calli were obtained from shoot apical tips of offshoots excised in small pieces cultured on solid medium with low concentrations of growth regulators. The calli formed were friable white and yellow nodular. The isolation of protoplasts was achieved by transferring the plant material in enzymatic solutions in the dark. The yield of protoplasts obtained was sufficient to initiate a protoplast culture. Generally, the number of protoplasts obtained was more than 1.5×10⁶. The protoplasts were cultured in both liquid and nurse culture. In terms of cell division rate, cell division was induced in both liquid culture and on nurse culture, but the best culture system was the feeder layer. The dividing cells developed to microcalli, which developed to calli on modified Murashige and Skoog medium. Calli were picked up and transferred on regeneration media to initiate plant organs.