Fern Conservation: Spore, Gametophyte, and Sporophyte Ex Situ Storage, In Vitro Culture, and Cryopreservation

Chapter

Abstract

Many species of ferns and lycophytes are threatened by habitat destruction, over-collecting, invasive species, and climate change, and plans to secure their in situ and ex situ conservation are urgently needed. However, there has not been a development of standard methods for fern ex situ storage and conservation, as there has been for seed plants. This is likely due to the fact that ferns have been less studied and are less understood than seed plants and that there has been less funding and institutional focus on them for conservation purposes when compared with domesticated or wild seed plants. Tissues from different stages of the fern and lycophyte life cycle can be used as a ready source of germplasm for ex situ conservation. Spore storage is generally the most efficient method for ex situ fern conservation, but there are also situations where storing gametophytes or sporophytes can be extremely useful. The longevity of spores at −20 °C, the standard seed banking temperature, may vary with the species. Storage in LN should improve longevity in spores and is likely necessary for non-spore tissues. Recent results of a study on the viability of spores, gametophytes, and sporophytes after 20 years of storage in liquid nitrogen is used as a case study to illustrate the potential of these methods. The state of current methods and needs for further research and application are discussed. While there is much more to learn, these tools are available for fern ex situ conservation and should be implemented on a broader scale to preserve rare fern taxa and provide materials for future restoration and research.

Keywords

Cryopreservation Ex situ conservation Gametophyte Liquid nitrogen Spore 

Notes

Acknowledgements

We would like to thank Callihan A and Lindsey K for their contribution to the propagation and acclimation of diverse fern species at CREW and Thomas A and Stewart K for the work on the initial banking of spores and gametophytes. Also special thanks to Barber S, Pritchard H, Dickie J, Davies R (UK), Estrelles E (Spain), Mikula A (Poland), Magrini S (Italy), Walters C, Hill L, Wolkis D (USA), Reyes-Jaramillo I (Mexico), Randi M (Brazil), Sershen (South Africa), Huang YM (Taiwan), Cicuzza D, Bin W, Yang X-Y (China), Schnell J, McGill C (New Zealand), and Offord C (Australia) for their contributions in the development of Table 11.1 and Suggii N and From M for information on in vitro sporophyte collections. Fern spore, gametophyte, and sporophyte collections used in this work would not be possible without the help and the donations of multiple collectors and researchers from diverse institutions, including Bannister S, Yoshinaga A, Kawakami K, and staff of the Krohn Conservatory.

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© Springer International Publishing AG, part of Springer Nature 2018

Authors and Affiliations

  1. 1.Center for Conservation and Research of Endangered WildlifeCincinnati Zoo & Botanical GardenCincinnatiUSA
  2. 2.Comparative Seed Biology Group, Comparative Plant and Fungal Biology DepartmentRoyal Botanic Gardens KewRichmondUK

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