Exposure of pineapple shoot tips to liquid nitrogen and cryostorage do not affect the histological status of regenerated plantlets

Abstract

Conservation of pineapple (Ananas comosus L. Merr.) genetic resourcesincluding cryopreservation in liquid N2 at-196°Cis essential for future breeding programmes to develop new varieties with improved agronomic performance. However, the potentially deleterious effects of cryopreservation on subsequent plant regrowth should be evaluated before large-scale development of cryobanks is implemented. This paper describes the histological analysis of pineapple plantlets regenerated from cryopreserved shoot tips. Two controls were included in the study: i) conventional micropropagation-derived plantlets, and ii) plants from shoot tips subjected to pre-cryostorage conditioning treatments but never exposed to liquid N2. Histological studies of roots, leaves and stems were conducted after 45 days of hardening. No statistically significant differences with the controls were observed in any of the histological parameters evaluated, which supports the practical value of cryopreservation of pineapple germplasm.

Morpho-Anatomical and Physiological Assessments of Cryo-Derived Pineapple Plants (Ananas comosus var. comosus) after Acclimatization

“…The newly developed leaves that adapted to ex vitro conditions (Figure 1B,E,H) exhibited a growth pattern with a more vertical orientation and increased width, which is indicative of greater metabolic efficiency and physiological adaptation to the specific environmental conditions [44]. These leaves exhibited a perfectly defined anatomical structure (Figure 1C,F,I), similar to that previously observed by Villalobos-Olivera et al [28] and González et al [46] in acclimatized pineapple plants from in vitro systems. These leaves exhibited the aquifer parenchyma, a specialized structure of plants with CAM metabolism that allows for higher efficiency in water use [36,57,58].…”

“…Several research papers have mentioned success in acclimating cryo-derived pineapple plants [10,[26][27][28]. However, there have been only a few studies on assessments of morpho-anatomical characteristics in cryo-derived pineapple plants during/after acclimatization [26,28].…”

“…Several research papers have mentioned success in acclimating cryo-derived pineapple plants [10,[26][27][28]. However, there have been only a few studies on assessments of morpho-anatomical characteristics in cryo-derived pineapple plants during/after acclimatization [26,28]. Furthermore, these studies do not describe the metabolic changes in cryo-derived plants during the transition from the in vitro to the ex vitro environment.…”