Effect of Cryopreservation on the Ex Vitro Establishment of Olive Plants Regenerated via Somatic Embryogenesis

Abstract

Cryopreservation is considered the best technique for the safe, long-term conservation of embryogenic cultures. However, before integrating it into a somatic embryogenesis system, the influence of cryopreservation on the final production of plants should be investigated. The objective of this investigation was to evaluate the effect of cryopreservation on the regeneration performance of olive embryogenic cultures as well as on the quality of the plants obtained and their response to ex vitro establishment. In order to analyze the influence of the genotype, all the investigations were carried out in two genetically distinct embryogenic lines. The results obtained revealed no variation in the regeneration potential or the quality of the regenerated plants due to cryopreservation. The subsequent multiplication, rooting, and acclimatization steps were not influenced by cryopreservation either, although a significant genotype × cryopreservation interaction was found for shoot length during the multiplication step. The genotype played an important role, determining the quality of the regenerated plants and some aspects of the multiplication and rooting phases. This investigation revealed that the droplet-vitrification procedure optimized for the cryopreservation of olive somatic embryos can be efficiently used for the long-term conservation of olive embryogenic lines.

Cryopreservation of Indigenous Plums and Monitoring of Multiplication and Rooting Capacity of Shoots Obtained from Cryopreserved Specimens

“…A significant decrease in the multiplication capacity of shoots regenerated from cryo-preserved explants using droplet vitrification was also reported in apple [54], while shoots of cherry plum were even unable to multiply over two successive subcultures after regrowth [55]. On the other hand, the multiplication step of olive cultures established from somatic embryos was not affected by cryo-preservation, although a significant interaction between genotype and cryo-preservation was found for shoot length during multiplication [56].…”

“…Considering rooting rate as a parameter of rooting ability, shoots of all genotypes regenerated from explants cryo-preserved by the D cryo-plate method and of five genotypes cryo-preserved using the V cryo-plate method rooted with equal efficiency as dissection controls, while other rooting parameters varied significantly; the direction of variation depended on the genotype and the parameter being monitored. Bradaï and Sánchez-Romero [56] observed no significant differences in the parameters assessed in the rooting and acclimatization phases of olive plantlets regenerated from cryo-preserved embryogenic cultures. Nonetheless, slightly higher values of rooting percentage, number of roots per rooted shoot, and root length were achieved in shoots derived from cryo-preserved cultures of some lines compared with those obtained in control and unfrozen cultures.…”

Optimization of Key Technologies for Induction of Embryogenic Callus and Maturation of Somatic Embryos in Korean Pine (Pinus koraiensis)

“…Therefore, EC cryopreservation technology is of great significance [45]. After cryopreservation, the culture can be restored at any time when needed.…”

Somatic Embryogenesis in Olive

“…In a second article, Bradaï and Sánchez-Romero [42] investigated the influence of cryopreservation on the regeneration performance of olive embryogenic cultures and the quality of the plants obtained, analyzing their behavior on the subsequent steps required for ex vitro plant establishment. No effect of cryopreservation could be observed on the regeneration potential or the regenerated plants.…”