In vitro preservation of date palm (phoenix dactylifera l.)‎ embryogenic callus

Abstract EN

n vitro medium term conservation of tropical plant germplasm is widely used for most plant species.

Changes in the physical or chemical conditions had been used as a strategy for reducing the in vitro plant metabolism and prolonging the cultivation period.

Embryogenic callus cultures of Oshkingbeel and Friahy date palm cultivars were derived from shoot tip explants using Murashige and Skoog (MS) medium supplemented with 10 mg/l dichlorophenoxy acetic acid (2,4-D) and 3 mg/l 2- isopentenyladenine (2iP).

Cultures were stored at two temperature (20 and 27±2°C) in complete darkness.

Cultures were also subjected to different osmotic agents (sucrose and sorbitol) at different concentrations (0.087, 0.1, 0.2 or 0.4 M), which were added to medium supplemented with 10 mg /l 2,4-D and 3 mg/l 2iP.

Every three months of storage up to 15 months, cultures were evaluated for percentage of survived and germinated embryos.

After 15 months, the temperature of 20°C was more effective for the in vitro conservation of both cultivars concerning survival percentage and number of germinated embryos.

At this temperature, after 15 months of storage, the highest survival percentage was 86.7 and 93.3% for cvs Oshkingbeel and Friahy, respectively.

For osmotic agents, after 15 months, the highest survival percentage (66.7 %) was recorded with sorbitol at 0.4 M or sucrose at 0.2 M for cv Fraihy, whereas 60% of cv Oshkingbeel cultures were able to survive when preserved on medium containing 0.2 M sucrose.

Sorbitol at its different concentrations and 0.2 M sucrose were the most appropriate treatments for maintaining the cultures and increasing the number of germinated embryos of cvs Oshkingbeel and Fraihy cultures after the tested storage periods.