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Effects of developmental status and dehydration rate on characteristics of water and desiccation-sensitivity in recalcitrant seeds of Camellia sinensis

Published online by Cambridge University Press:  19 September 2008

Patricia Berjak*
Affiliation:
Plant Cell Biology Research Unit, Department of Biology, University of Natal, King George V Ave, Durban, 4001South Africa
Christina W. Vertucci
Affiliation:
U.S. Department of Agriculture, Agriculture Research Service, National Seed Storage Laboratory, Fort Collins, CO 80523, USA
N. W. Pammenter
Affiliation:
Plant Cell Biology Research Unit, Department of Biology, University of Natal, King George V Ave, Durban, 4001South Africa
*
* Correspondence

Abstract

The effect of rate of dehydration was assessed for embryonic axes from mature seeds of Camellia sinensis and the desiccation sensitivity of axes of different developmental stages was estimated using electrolyte leakage. Rapidly (flash) dried excised axes suffered desiccation damage at lower water contents (0.4 g H2O (g DW)−1) than axes dried more slowly in the whole seed (0.9 g H2O (g DW)−1). It is possible that flash drying of isolated axes imposes a stasis on deteriorative reactions that does not occur during slower dehydration. Differential scanning calorimetry (DSC) of the axes indicated that the enthalpy of the melting and the amount of non-freezable water were similar, irrespective of the drying rate.

Very immature axes that had completed morphogenesis and histodifferentiation only were more sensitive to desiccation (damage at 0.7 g H2O (g DW)−1) than mature axes or axes that were in the growth and reserve accumulation phase (damage at 0.4 g H2O (g DW)−1). As axes developed from maturity to germination, their threshold desiccation sensitivity increased to a higher level (1.3−1.4 g H2O (g DW)−1). For the very immature axes, enthalpy of the melting of tissue water was much lower, and the level of non-freezable water considerably higher, than for any other developmental stage studied.

There were no marked correlations between desiccation sensitivity and thermal properties of water. Desiccation sensitivity appears to be related more to the degree of metabolic activity evidenced by ultrastructural characteristics than to the physical properties of water.

Type
Research Papers
Copyright
Copyright © Cambridge University Press 1993

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References

Berjak, P., Farrant, J.M. and Pammenter, N.W. (1989) The basis of recalcitrant seed behaviour. Cell biology of the homoiohydrous seed condition. pp 89108in Taylorson, R.B. (Ed.) Recent advances in the development and germination of seeds. New York, Plenum Press.CrossRefGoogle Scholar
Berjak, P., Pammenter, N.W. and Vertucci, C.W. (1992) Homoiohydrous (recalcitrant) seeds: Developmental status, desiccation sensitivity and the state of water in axes of Landolphia kirkii Dyer. Planta 186, 249261.CrossRefGoogle ScholarPubMed
Derbyshire, W. (1982) The dynamics of water in heterogeneous systems with emphasis on subzero temperatures. pp 339450in, Franks, F. (Ed.) Water, a comprehensive treatise, Vol 7: Water and aqueous solutions at subzero temperatures. New York, London, Plenum Press.CrossRefGoogle Scholar
Ellis, R.H., Hong, T.D. and Roberts, E.H. (1990) An intermediate category of seed storage behaviour? I. Coffee. Journal of Experimental Botany 41, 11671174.CrossRefGoogle Scholar
Ellis, R.M., Hong, T.D., Roberts, E.H. and Soetisna, U. (1991) Seed storage behaviour in Elaeis guineensis. Seed Science Research 1,99104.CrossRefGoogle Scholar
Farrant, J.M., Berjak, P. and Pammenter, N.W. (1985) The effect of drying rate on viability retention of recalcitrant propagules of Avicennia marina.South African Journal of Botany 51, 432438.CrossRefGoogle Scholar
Farrant, J.M., Pammenter, N.W. and Berjak, P. (1986) The increasing desiccation sensitivity of recalcitrant Avicennia marina seeds with storage time. Physiologia Plantarum 67, 291298.CrossRefGoogle Scholar
Farrant, J.M., Pammenter, N.W. and Berjak, P. (1988) Recalcitrance—a current assessment. Seed Science and Technology 16, 155166.Google Scholar
Farrant, J.M., Berjak, P. and Pammenter, N.W. (1993) Studies on the development of the desiccation sensitive seeds of Avicennia marina (Forssk.) Vierh.: The acquisition of germinability and response to storage and dehydration. Annals of Botany. In press.CrossRefGoogle Scholar
Finch-Savage, W.E. (1992a) 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. (1992b) Seed development in the recalcitrant species Quercus robur L.: germinability and desiccation tolerance. Seed Science Research 2, 1722.CrossRefGoogle Scholar
Hong, T.D. and Ellis, R.H. (1990) A comparison of maturation drying, germination, and desiccation tolerance between developing seeds of Acer pseudoplatanus L. and Acer platanoides L. New Physiologist 116, 589596.CrossRefGoogle 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
Pritchard, H.W. (1991) Water potential and embryonic axis viability in recalcitrant seeds of Quercus rubra. Annals of Botany 67, 4349.CrossRefGoogle Scholar
Pritchard, H.W. and Prendergast, F.G. (1986) Effects of desiccation and cryopreservation on the in vitro viability of embryos of the recalcitrant seed species Araucaria huntsteinii, Shumk. Journal of Experimental Botany 37, 13881397.CrossRefGoogle Scholar
Senaratna, T. and McKersie, B.D. (1983) Dehydration injury in germinating soybean (Glycine max L. Merr.) seeds. Plant Physiology 72,620624.CrossRefGoogle ScholarPubMed
Vertucci, C.W. (1989) Relationship between thermal transitions and freezing injury in pea and soybean seeds. Plant Physiology 90, 11211128.CrossRefGoogle ScholarPubMed
Vertucci, C.W. (1990) Calorimetric studies of the state of water in seed tissues. Biophysical Journal 58, 14631471.CrossRefGoogle ScholarPubMed
Vertucci, C.W. and Leopold, A.C. (1987) The relationship between water binding and desiccation tolerance in tissues. Plant Physiology 85, 232238.CrossRefGoogle ScholarPubMed
Vertucci, C.W., Berjak, P., Pammenter, N.W. and Crane, J. (1991) Cryopreservation of embryonic axes of an homoiohydrous (recalcitrant) seed species in relation to calorimetric properties of tissue water. Cryo Letters 12, 339350.Google Scholar
Wesley-Smith, J., Vertucci, C.W., Berjak, P., Pammenter, N.W. and Crane, J.(1992) Cryopreservation of desiccation sensitive axes of Camellia sinensis in relation to dehydration, freezing rate and the thermal properties of tissue water. Journal of Plant Physiology 140, 596604.CrossRefGoogle Scholar