Y.L. Hor P.C. Stanwood and H.F. Chin
Pertanika Journal of Tropical Agricultural Science, Volume 16, Issue 2, August 1993
Keywords: Cryopreservation, Coffea liberica, desiccation, freezing treatments
Published on:
Desiccation of Coffea liberica seeds for 6 days in an air-conditioned room reduced seed and attached embryo moisture from 52.58% and 47.49% to 14.58% and 12.56% respectively. Seed germination and viability of the attached embryo were maintained at moderate levels of 66% and 38 % respectively. However, none of the desiccated seeds or embryos survived freezing in liquid nitrogen. Excised embryos desiccated in the lamina flow cabinet lost their moisture very rapidly from 36.8% to 9.27% within 1.5 hours. More than 70% of these embryos survived the desiccation. Moreover, partially desiccated embryos at 17.17% moisture or less survived subfreezing temperatures. Between 35% to 50% survived slow freezing to -38°C, but this was reduced to approximately 30% when they were subsequently plunged into liquid nitrogen. Fast freezing by direct plunge into liquid nitrogen also resulted in 10% to 35 % survival. Desiccation of excised coffee embryos for 0.5h to 17.17% moisture was optimal for cryopreservation, irrespective of the speed of freezing. Differential thermal analyses of seed tissues suggest that the absence of freezable water is an important factor for successful cryopreservation of excised coffee embryos. However, the importance of initial vigour, moisture variation and recovery media is also discussed.
ISSN 1511-3701
e-ISSN 2231-8542