CRYOPRESERVATION OF COFFEE (COFFEA-ARABICA L.) SEEDS - IMPORTANCE OF THE PRECOOLING TEMPERATURE

the effect of the precooling temperature on the survival rate of cryop reserved Coffea arabica seeds and excised zygotic embryos was investig ated. Seeds were desiccated to 0.2 g H2O.g(-1) dw, then cooled at 1 de grees C.min(-1) to various precooling temperatures. The optimal germin ation rate (70%) of cryopreserved seeds was achieved after precooling to -50 degrees C. After 4 months in culture, 30% of seeds developed in to normal seedlings. For embryos extracted after thawing from cryopres erved seeds, maximal survival rate (97%) was observed when seeds were immersed into liquid nitrogen directly after dehydration, without prec ooling. All viable embryos developed into normal seedlings after 2 mon ths in culture.