Effect of different conservation periods with different sucrose concentrations on conserving somatic embryo clusters of date palm (Phoenix dactylifera L.) under minimal growth

The present study was conducted to investigate the possibility of using in vitro slow growth 
storage for date palm (Phoenix dactylifera L.) germplasm conservation to promote germplasm 
exchange and rapid propagation when necessary. Multiplied somatic embryo clusters of date palm 
cv. Sukkary were used as the conserved explants. Different conservation periods (4, 8, and 12 
months) with different sucrose concentrations (30, 60, 90 or 120 g/l) supplemented to conservation 
medium which consists of 1/2 strength Murashige and Skoog (MS) basal salts medium, 30 g/l 
mannitol, 0.05 mg/l (BA) benzyladenin, 0.1 mg/l (NAA) naphthalene acetic acid and 8 g/l agar, 
under low temperature (15 C) and dark incubation  conditions, were examined to determine the  
survival and re-growth capacity of conserved explants after returning to the normal growth 
conditions. Contents of total soluble sugars (TSS), non reducing sugars (NRS) and reducing sugars 
(RS) were also determined as physiological changes during conservation periods. Results showed 
that conservation medium supplemented with 90 or 120 g/l sucrose gave the highest significant 
value of survival percentage, after 12 month conservation period. Best recovery performance under 
normal growth conditions for conserved somatic embryo clusters under studied minimal growth 
conditions was achieved when 90 g/l sucrose was used in conservation medium for 8 months