Recovery and Histological Changes of Date Palm Somatic Embryos After Crypreservation By Dehydration

Bekheet, Shawky; Amer, Ahmed M.; Sota, Valbona

doi:10.21608/ejchem.2024.288440.9694

Recovery and Histological Changes of Date Palm Somatic Embryos After Crypreservation By Dehydration

Document Type : Original Article

Authors

¹ Department of Plant Biotechnology, National Research Centre

² Department of Plant Biotechnology, Biotechnology Research Institute, National Research Centre

³ Department of Biotechnology, Faculty of Natural Sciences, University of Tirana, Albania

10.21608/ejchem.2024.288440.9694

Abstract

Cryopreservation of plant materials is the storage in liquid nitrogen (LN) in such a way, that viability is maintained and regeneration is obtained after rewarming. In this study, cryopreservation of date palm somatic embryos was examined through dehydration by air drying (20, 40, 60 and 80 minutes) or osmotic dehydration caused by sucrose (0.5, 1.0 and 1.5 M). After two months of cryostorage, survival, re-growth and recovery parameters were registered. Furthermore, the ultrastructure of somatic embryos cells was studied after cryostorage. Among three drying periods, the best results of survival were observed with 60 min exposure to air-flow cabinet. Also, the highest values of recovery parameters i.e., number of secondary embryos, embryos germination and numbers of proliferated shootlets were obtained using 60 min exposure period. Regarding osmotic dehydration, the maximum values of survival (50 %) and re-growth (45 %) were counted when somatic embryos were dehydrated by 1.0 M sucrose prior to cryopreservation. Also, the highest number of second embryos (5.90) was registered when somatic embryos were dehydrated with 1.0 M and 85 % of the embryos were able to germinate into healthy propagule. However, using 1.5 M sucrose for dehydration induced highest number of proliferated shootlets (5.50) after ten weeks of culturing on recovery medium. Histological screening revealed that cryopreservation by dehydration caused minimal cellular damage within the cells of date palm somatic embryos. Comparing to the non-cryopreserved cultures, some cell walls were broken and vacuole size and cytoplasm density were increased. The cells suffered some damage could divide and regenerate into normal tissues. Depending on our finding, we can conclude that dehydration especially osmotic dehydration (1.0 M sucrose) is an effective method can be used for cryopreservation of date palm tissue cultures.

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