|Wesley-Smith, James - UNIV. OF KWAZULU-NATAL|
|Chmielarz, Pawel - POLISH ACADEMY OF SCIENCE|
|Pammenter, Norman - UNIV. OF KWAZULU-NATAL|
|Berjak, Patricia - UNIV. OF KWAZULU-NATAL|
Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: October 17, 2006
Publication Date: January 1, 2008
Citation: Walters C, J. Wesley-Smith, J. Crane, L.M. Hill, P. Chmielarz, N.W. Pammenter and P. Berjak. 2008. Cryopreservation of recalcitrant (i.e. desiccation-sensitive) seeds. pp. 465-484. In B. Reed (ed.) Plant Cryopreservation: A practical guide. Springer Publishing, New York, NY. Interpretive Summary: Approximately 10 to 20% of angiosperm species produce seeds that do not survive complete desiccation. These so-called “recalcitrant” seeds also do not survive conventional storage conditions used in genebanks. However, seeds from many of these species are amenable to cryopreservation. Cryopreservation is largely an engineering problem, and the physical attributes of the tissue or propagule are dominant factors in developing successful procedures. This book chapter details cryopreservation techniques used for recalcitrant seeds.
Technical Abstract: “Recalcitrant” seeds do not survive conventional storage conditions used in genebanks and so must be cryopreserved. Many of the procedures used to cryopreserve recalcitrant seeds balance damage induced by desiccation and freezing stresses, and mitigate the latter through rapid cooling treatments. The main physical attributes to consider for various cryopreservation strategies are the water potential, water content and size of the selected tissue to be cryoexposed. Physiological attributes consider desiccation tolerance, in-vitro germination procedures and cryoprotectants. Mortality resulting from cryoexposure may impose severe and inadvertent selection pressures on genes that regulate phenology, embryo development and germination.