Efficiency of cryoprotectants for in vitro and ex vitro germination of cryopreserved Jatropha curcas seeds

Abstract

To investigate the effects of different cryoprotectants on germination and seedling development of jatropha (Jatropha curcas L.) seeds after cryopreservation, two experiments were performed under in vitro and ex vitro conditions. Nine treatments were used for both experiments, as follows: T1-No cryoprotectants (control); T2- glycerol 2 M (20minutes); T3-sucrose 0.4 M (20minutes); T4-glycerol 2 M (20minutes) + PVS2 (10minutes);T5-glycerol 2M(20minutes) + PVS2 + phloroglucinol1%(10minutes); T6-sucrose 0.4 M (20 minutes) + PVS2 (10 minutes); T7-sucrose 0.4 M (20 minutes) + PVS2 + phloroglucinol 1% (10 minutes); T8-glycerol 2 M (20 minutes) + sucrose 0.4 M (20 minutes) + PVS2 (10 minutes); and T9-glycerol 2 M (20 minutes) + sucrose 0.4 M (20 minutes) + PVS2 (10 minutes) + phloroglucinol 1% (10 minutes). After cryopreservation, seeds without cryoprotectants (T1) or with sucrose 0.4 M + PVS2 (T6) returned the best germination percentages after seven days of in vitro culture, 29.5% and 25%, respectively. However, they were not significantly different. For the ex vitro experiment, seed germination percentage was higher in organic substrate. These results indicate that cryopreservation of jatropha seeds can be accomplished without cryoprotectants, and faster germination is obtained in organic substrate.