The recalcitrant seeds rambutan( Nephelium lappaceum). durian (Durio zibethinus) and cempedak
(Artocarpus inleger) have a high critical moisture content (below which ·rapid loss of viability occurs of
27.0%, 26.0% and 37.9%,respectively. The critical moisture for embroys were higher at 39.0%
for rambutan, 53.9% for durian and 43.2% for Cempedak. Differential Thermal analysis of the embroyos
confirmed that their threshhold moistures (below which there is no freezable water) were lower than their critical
moistureS. The Threshhold moistures for rambutan, durian and cempedak embryos were approximately 30%,
32% and 33% respectively. It is suggested that unsuccessful attempts at cryopreservation of embroyos of
'recalcitrant seeds in the past maybe due to the absence of safe window between the high critical moisture
content and the threshhold moisture. This results in freezing injury at the higher moistures and dehydration
injury' at the lower moistures. Potential techniques to overcome this and improve cryopreservation of recalcitrant
seed embryos are discussed
