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Effects of differential drying rates on viability retention of recalcitrant seeds of Ekebergia capensis

Published online by Cambridge University Press:  19 September 2008

N. W. Pammenter*
Affiliation:
Plant Cell Biology Research Unit, Department of Biology, University of Natal, Durban, 4041 South Africa
Valerie Greggains
Affiliation:
NERC Unit of Comparative Plant Ecology, Department of Animal and Plant Sciences, The University, Sheffield S10 2TN, UK
J. I. Kioko
Affiliation:
Plant Cell Biology Research Unit, Department of Biology, University of Natal, Durban, 4041 South Africa
J. Wesley-Smith
Affiliation:
Plant Cell Biology Research Unit, Department of Biology, University of Natal, Durban, 4041 South Africa
Patricia Berjak
Affiliation:
Plant Cell Biology Research Unit, Department of Biology, University of Natal, Durban, 4041 South Africa
W. E. Finch-Savage
Affiliation:
3Horticulture Research International, Wellesbourne, Warwick CV35 9EF, UK
*
*Fax: +27 31 260 2029 E-mail: [email protected]

Abstract

The drying rate of whole seeds of Ekebergia capensis (Meliaceae) was shown to influence the response to desiccation, with rapidly dried seeds surviving to lower water contents. Short-term rapid drying (to water contents higher than those leading to viability loss) actually increased the rate of germination. The form of the time course of decline of axis water content varied with drying rate; slow drying could be described by an exponential function, whereas with rapid drying initial water loss was faster than predicted by an exponential function. These observations suggest that slow drying brought about homogeneous dehydration and that the rapid drying was uneven across the tissue. This raised the possibility that the different responses to dehydration were a function of different distributions of water in the axis tissue under the two drying regimes. However, ultrastructural observations indicated that different deleterious processes may be occurring under the different drying treatments. It was tentatively concluded that a major cause of viability loss in slowly dried material was likely to be a consequence of aqueous-based processes leading to considerable membrane degradation. Uneven distribution of tissue water could not be rejected as a contributory cause of the survival of rapidly dried seeds to low bulk water contents. The differential response to dehydration at different drying rates implies that it is not possible to determine a ‘critical water content’ for viability loss by recalcitrant seeds.

Type
Physiology & Biochemistry
Copyright
Copyright © Cambridge University Press 1998

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References

Beckett, R.P. (1997) Pressure-volume analysis of a range of poikilohydric plants implies the existence of negative turgor in vegetative cells. Annals of Botany 79, 145152.CrossRefGoogle Scholar
Berjak, P. and Pammenter, N.W. (1997) Progress in the understanding and manipulation of desiccation-sensitive (recalcitrant) seeds. pp 689703in Ellis, R.M.; Black, M.; Murdoch, A.J.; Hong, T.D. (Eds) Basic and applied aspects of seed biology: Proceedings of the Fifth International Workshop on Seeds, Reading, 1995, Kluwer Academic Publishers.CrossRefGoogle Scholar
Berjak, P., Farrant, J.M. and Pammenter, N.W. (1989) The basis of recalcitrant seed behaviour. pp 89108in Taylorson, R.B. (Ed.) Recent advances in the development and germination of seeds. New York, Plenum Press.CrossRefGoogle Scholar
Berjak, P., Vertucci, C.W. and Pammenter, N.W. (1993) Effects of developmental status and dehydration rate on characteristics of water and desiccation-sensitivity in recalcitrant seeds of Camellia sinensis. Seed Science Research 3, 155166.CrossRefGoogle Scholar
Berjak, P., Farrant, J.M., Mycock, D.J. and Pammenter, N.W. (1990) Recalcitrant (homoiohydrous) seeds: the enigma of their desiccation-sensitivity. Seed Science and Technology 18, 297310.Google Scholar
Berjak, P., Mycock, D.J., Wesley-Smith, J., Dumet, D. and Watt, P. (1996) Strategies for in vitro conservation of hydrated germplasm. pp 1952in Normah, M.N.; Narimah, M.K.; Clyde, M.M. (Eds) In vitro conservation of plant genetic resources. Kuala Lumpur, Malaysia, Percetakan Watan Sdn.Bhd.Google Scholar
Chin, H.F. and Roberts, E.H. (1980) Recalcitrant crop seeds. Kuala Lumpur, Malaysia, Tropical Press SDN.BHD.Google Scholar
Corbineau, F., Salmen Espindola, L., Vinel, D. and Côme, D. (1997) Cellular and metabolic events associated with dehydration of recalcitrant Araucaria angustifolia embryos. pp 715721in Ellis, R.M.; Black, M.; Murdoch, A.J.; Hong, T.D. (Eds) Basic and applied aspects of seed biology: Proceedings of the Fifth International Workshop on Seeds, Reading, 1995, Kluwer Academic Publishers.CrossRefGoogle Scholar
Crowe, J.H., Crowe, L.M., Carpenter, J.F. and Aurell Wistrom, C. (1987) Stabilization of dry phospholipid bilayers and proteins by sugars. Biochemical Journal 242, 110.CrossRefGoogle ScholarPubMed
Farrant, J.M., Berjak, P. and Pammenter, N.W. (1985) The effect of drying rate on viability retention of propagules of Avicennia marina. South African Journal of Botany 51, 432438.CrossRefGoogle Scholar
Farrant, J.M., Pammenter, N.W., Berjak, P. and Walters, C. (1997) Subcellular organization and metabolic activity during the development of seeds that attain different levels of desiccation tolerance. Seed Science Research 7, 135144.CrossRefGoogle Scholar
Finch-Savage, W.E. (1992) Embryo water status and survival in the recalcitrant species Quercus robur L.: evidence for a critical moisture content. Journal of Experimental Botany 43, 663669.CrossRefGoogle Scholar
Finch-Savage, W.E. (1996) The rôle of developmental studies in research on recalcitrant and intermediate seeds. pp 8397in Poulsen, K., Stubsgaard, F. and Ouédraogo, A.-S. (Eds) Improved methods for the handling and storage of intermediate/recalcitrant tropical forest tree seeds. Rome, IPGRI.Google Scholar
Finch-Savage, W.E. and Blake, P.S. (1994) Indeterminate development in desiccation-sensitive seeds of Quercus robur L. Seed Science Research 4, 127133.CrossRefGoogle Scholar
Fu, J.R., Zhang, B.Z., Wang, X.P., Qiao, Y.Z. and Huang, X.L. (1990) Physiological studies on desiccation, wet storage and cryopreservation of recalcitrant seeds of three fruit species and their excised embryonic axes. Seed Science and Technology 18, 743754.Google Scholar
Leprince, O., Deltour, R. and Hendry, G.A.F. (1993) Impaired NADPH metabolism during loss of desiccation tolerance in germinating Zea mays seeds. pp 393397in Côme, D.; Corbineau, F. (Eds) Fourth international workshop on seeds. Basic and applied aspects of seed biology. Paris, ASFIS.Google Scholar
Leprince, O., Deltour, R., Thorpe, P.C., Atherton, N.M. and Hendry, G.A.F. (1990) The role of free radicals and radical processing systems in loss of desiccation tolerance in germinating maize (Zea mays L.) seeds. New Phytologist 116, 573580.CrossRefGoogle Scholar
Normah, M.N., Chin, H.F. and Hor, Y.L. (1986) Desiccation and cryostorage of embryonic axes of Hevea brasiliensis Muell.-Arg. Pertanika 9, 299303.Google Scholar
Pammenter, N.W., Vertucci, C.W. and Berjak, P. (1991) Homeohydrous (recalcitrant) seeds: dehydration, the state of water and viability characteristics in Landolphia kirkii. Plant Physiology 96, 10931098.CrossRefGoogle ScholarPubMed
Pammenter, N.W., Vertucci, C.W. and Berjak, P. (1993) Responses to dehydration in relation to non-freezable water in desiccation-sensitive and -tolerant seeds. pp 867872in Côme, D.; Corbineau, F. (Eds) Fourth international workshop on seeds. Basic and applied aspects of seed biology. Paris, ASFIS.Google Scholar
Pritchard, H.W. (1991) Water potential and embryonic axis viability in recalcitrant seeds of Quercus rubra. Annals of Botany 67, 4349.CrossRefGoogle Scholar
Roberts, E.H. (1973) Predicting the storage life of seeds. Seed Science and Technology 1, 499514.Google Scholar
Salmen Espindola, L., Noin, M., Corbineau, F. and Côme, D. (1994) Cellular and metabolic damage induced by desiccation in recalcitrant Araucaria angustifolia embryos. Seed Science Research 4, 193201.CrossRefGoogle Scholar
Vertucci, C.W. (1990) Calorimetric studies on the state of water in seed tissues. Biophysical Journal 58, 14631471.CrossRefGoogle ScholarPubMed
Vertucci, C.W. (1993) Towards a unified hypothesis of seed aging. pp 739746in Côme, D.; Corbineau, F. (Eds) Fourth international workshop on seeds. Basic and applied aspects of seed biology. Paris, ASFIS.Google Scholar
Vertucci, C.W. and Farrant, J.M. (1995) Acquisition and loss of desiccation tolerance. pp 237271in Kigel, J.; Galili, G. (Eds) Seed development and germination. New York, Basel, Hong Kong, Marcel Dekker Inc.Google Scholar