IMPORTANCE OF SUCROSE FOR THE ACQUISITION OF TOLERANCE TO DESICCATIONAND CRYOPRESERVATION OF OIL PALM SOMATIC EMBRYOS

In the present work, the importance of preculture with high sucrose co ncentration for the acquisition of resistance of oil palm somatic embr yos to desiccation and cryopreservation was underlined. Survival of no n-pregrown control embryos decreased for dehydration periods longer th an 10 hrs. No survival was obtained after freezing in liquid nitrogen whatever the desiccation duration. With pregrown control embryos, 100% survival was noted whatever the dehydration period. Survival after fr eezing in liquid nitrogen was possible without dehydration (40%) but i t was dramatically improved after 12 (70%) and 16 hrs of desiccation ( 80%). Thermal analysis revealed that crystallization still occurred in non-pregrown embryos after 16 hrs of dehydration. With pregrown embry os, a glass transition only was recorded after dehydration periods of 12 and 16 hrs which ensured the highest survival rates.