Cryopreservation of Woody Crops: The Avocado Case

Abstract

Recent development and implementation of crop cryopreservation protocols has increased the capacity to maintain recalcitrant seeded germplasm collections via cryopreserved in vitro material. To preserve the greatest possible plant genetic resources globally for future food security and breeding programs, it is essential to integrate in situ and ex situ conservation methods into a cohesive conservation plan. In vitro storage using tissue culture and cryopreservation techniques offers promising complementary tools that can be used to promote this approach. These techniques can be employed for crops difficult or impossible to maintain in seed banks for long-term conservation. This includes woody perennial plants, recalcitrant seed crops or crops with no seeds at all and vegetatively or clonally propagated crops where seeds are not true-to-type. Many of the world’s most important crops for food, nutrition and livelihoods, are vegetatively propagated or have recalcitrant seeds. This review will look at ex situ conservation, namely field repositories and in vitro storage for some of these economically important crops, focusing on conservation strategies for avocado. To date, cultivar-specific multiplication protocols have been established for maintaining multiple avocado cultivars in tissue culture. Cryopreservation of avocado somatic embryos and somatic embryogenesis have been successful. In addition, a shoot-tip cryopreservation protocol has been developed for cryo-storage and regeneration of true-to-type clonal avocado plants.

Dielectric Properties of Phosphatidylcholine Membranes and the Effect of Sugars

“…The biological significance of carbohydrate molecules and developments of their biomedical and industrial applications have stimulated intensive research toward gaining knowledge of the alteration of membrane physicochemical properties by the presence of sugars. The protection of higher plant cells from the consequences of prolonged dehydration with the help of oligo-and polysaccharides represents a prominent example of the stabilizing effect exerted by sugars on biological membranes [1][2][3]. Simple carbohydrates represent one of the major protecting excipients in preservation of cells during freeze-drying [4].…”

On the Utility of Longwave-Infrared Spectral Imaging for Remote Botanical Identification

“…Initial analyses of the Huntington Gardens imagery revealed a regular array of trees near the facility's northern extremity that uniformly ID'd as Quercus robur. This proved to be an orchard of Persea americana (avocado) trees comprising a collection of numerous P. americana cultivars that supports a cryopreservation research program [39].…”

Cryopreservation of Hazelnut (Corylus avellana L.) Axillary Buds from In Vitro Shoots Using the Droplet Vitrification Method

“…The PVS2 treatment applied for 90 min induced a greater reduction in regrowth (60.0%) in the control (−LN) explants than the same duration of PVS3 application (70.0%), further suggesting that for the hazelnut axillary buds PVS3 is less toxic than PVS2. This response could be related to the presence of DMSO in the composition of PVS2, which can cause damage at cellular levels [56,59,60].…”