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Relationship between accumulated hydrothermal time during seed priming and subsequent seed germination rates

Published online by Cambridge University Press:  19 September 2008

Kent J. Bradford  and
Anthony M. Haigh
Kent J. Bradford*
Affiliation:
Department of Vegetable Crops, University of California, Davis, CA 95616-8631, USA
Anthony M. Haigh
Affiliation:
Faculty of Horticulture, University of Western Sydney, Hawkesbury, Richmond, NSW 2753, Australia
*
* Correspondence
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Abstract

Seed germination rates are sensitive to both temperature (T) and water potential (ψ). The times to germination of seeds imbibed at suboptimal T and/or reduced ψ are inversely proportional to the amounts by which T exceeds a base temperature (Tb) and ψ exceeds a base water potential (ψb). Germination rates across a range of suboptimal T and ψ can be normalized on the basis of the hydrothermal time accumulated in excess of these thresholds. However, seeds can also progress metabolically toward germination even at T or ψ too low to allow radicle emergence to occur. Seeds preimbibed at low ψ and dried back, or primed, germinate more rapidly upon subsequent reimbibition. We show here that the increase in germination rates of tomato (Lycopersicon esculentum Mill.) seeds resulting from seed priming is linearly related to the hydrothermal time accumulated during the priming treatment. The threshold temperature (Tmin = 7.05°C) and water potential (ψmin = −2.50 MPa) for metabolic advancement were considerably lower than the corresponding thresholds for radicle emergence of the same seed lot (Tb = 11°C; ψb = −0.71 MPa), allowing the accumulation of hydrothermal priming time that is subsequently expressed as more rapid germination when T or ψ increase. The hydrothermal time model can now be applied to quantify and analyse germination rates of seeds across the entire range of suboptimal T and ψ at which metabolic progress toward radicle emergence is possible.

Keywords

Hydrothermal timeLycopersicon esculentum Millseed germinationseed primingtemperaturetomatowater potential
Type
Research Papers
Information
Seed Science Research , Volume 4 , Issue 2 , June 1994 , pp. 63 - 69
Copyright
Copyright © Cambridge University Press 1994

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References

Akers, S.W. and Holley, K.E. (1986) SPS: a system for priming seeds using aerated, polyethylene glycol or salt solutions. HortScience 21, 529–531.CrossRefGoogle Scholar
Ali, A., Machado, V.S. and Hamill, A.S. (1990) Osmo-conditioning of tomato and onion seeds. Scientia Horticulturae 43, 213–224.CrossRefGoogle Scholar
Allen, P.S., Debaene, S.B.G. and Meyer, S.E. (1993) Regulation of grass seed germination under fluctuating moisture regimes. pp 387–392 in Côme, D. and Corbineau, F. (Eds) Proceedings, fourth international workshop on seeds: Basic and applied aspects of seed biology. Paris, Association pour la Formation Professionelle de l'Interprofession Semences.Google Scholar
Argerich, C.A. and Bradford, K.J. (1989) The effects of priming and ageing on seed vigour in tomato. Journal of Experimental Botany 40, 599–607.CrossRefGoogle Scholar
Battaglia, M. (1993) Seed germination physiology of Eucalyptus delegatensis R.T. Baker in Tasmania. Australian Journal of Botany 41, 119–136.CrossRefGoogle Scholar
Bradford, K.J. (1986) Manipulation of seed water relations via osmotic priming to improve germination under stress conditions. HortScience 21, 1105–1112.CrossRefGoogle Scholar
Bradford, K.J. (1990) A water relations analysis of seed germination rates. Plant Physiology 94, 840–849.CrossRefGoogle ScholarPubMed
Bradford, K.J. (1994) Water relations in seed germination. In press in Kigel, J., Galili, G., (Eds) Seed development and germination. New York, Marcel Dekker, Inc.Google Scholar
Coolbear, P. and McGill, C.R. (1990) Effects of a low-temperature pre-sowing treatment on the germination of tomato seeds under temperature and osmotic stress. Scientia Horticulturae 44, 43–54.CrossRefGoogle Scholar
Dahal, P. and Bradford, K.J. (1990) Effects of priming and endosperm integrity on seed germination rates of tomato genotypes. II. Germination at reduced water potential. Journal of Experimental Botany 41, 1441–1453.CrossRefGoogle Scholar
Dahal, P. and Bradford, K.J. (1994) Hydrothermal time analysis of tomato seed germination at suboptimal temperature and reduced water potential. Seed Science Research 4, 71–80.Google Scholar
Dahal, P., Bradford, K.J. and Jones, R.A. (1990) Effects of priming and endosperm integrity on seed germination rates of tomato genotypes. I. Germination at suboptimal temperature. Journal of Experimental Botany 41, 1431–1439.CrossRefGoogle Scholar
Dahal, P., Bradford, K.J. and Haigh, A.M. (1993) The concept of hydrothermal time in seed germination and priming. pp 1009–1014 in Côme, D. and Corbineau, F. (Eds) Proceedings, fourth international workshop on seeds: Basic and applied aspects of seed biology. Paris, Association pour la Formation Professionelle de l'Interprofession Semences.Google Scholar
Finch-Savage, W.E. and Phelps, K. (1993) Onion (Allium cepa L.) seedling emergence patterns can be explained by the influence of soil temperature and water potential on seed germination. Journal of Experimental Botany 44, 407–414.Google Scholar
Fyfield, T.P. and Gregory, P.J. (1989) Effects of temperature and water potential on germination, radicle elongation and emergence of mungbean. Journal of Experimental Botany 40, 667–674.CrossRefGoogle Scholar
Gordon, A.G. (1973) The rate of germination. pp 391–409 in Heydecker, W. (Ed.) Seed ecology. London, Butterworths.Google Scholar
Gray, D., Steckel, J.R.A. and Hands, L.J. (1990) Responses of vegetable seeds to controlled hydration. Annals of Botany 66, 227–235.CrossRefGoogle Scholar
Gummerson, R.J. (1986) The effect of constant temperatures and osmotic potential on the germination of sugar beet. Journal of Experimental Botany 37, 729–741.CrossRefGoogle Scholar
Haigh, A.M. (1988) Why do tomato seeds prime? Physiological investigations into the control of tomato seed germination and priming. PhD Dissertation, Macquarie University, Sydney, Australia.Google Scholar
Haigh, A.M., Barlow, E.W.R., Milthorpe, F.L. and Sinclair, P.J. (1986) Field emergence of tomato, carrot and onion seeds primed in an aerated salt solution. Journal of the American Society for Horticultural Science 111, 660–665.CrossRefGoogle Scholar
Hanson, A.D. (1973) The effects of imbibition drying treatments on wheat seeds. New Phytologist 72, 1063–1073.Google Scholar
Hegarty, T.W. (1977a) Seed activation and seed germination under moisture stress. New Phytologist 78, 349–359.Google Scholar
Hegarty, T.W. (1977b) Seed and seedling susceptibility to phased moisture stress in soil. Journal of Experimental Botany 28, 659–668.Google Scholar
Hegarty, T.W. (1978) The physiology of seed hydration and dehydration, and the relation between water stress and the control of germination: a review. Plant Cell and Environment 1, 101–119.CrossRefGoogle Scholar
Heydecker, W. (1973) Germination of an idea: the priming of seeds. University of Nottingham School of Agriculture Report 1973/1974, 50–67.Google Scholar
Heydecker, W. and Coolbear, P. (1977) Seed treatments for improved performance. Survey and attempted prognosis. Seed Science and Technology 5, 353–425.Google Scholar
Khan, A.A. (1992) Preplant physiological seed conditioning. Horticultural Reviews 14, 131–181.CrossRefGoogle Scholar
McKeon, G.M. (1985) Pasture seed dynamics in a dry monsoonal climate. II. The effect of water availability, light and temperature on germination speed and seedling survival of Stylosanthes humilis and Digitaria ciliasis. Australian Journal of Ecology 10, 149–163.Google Scholar
Michel, B.E. (1983) Evaluation of the water potentials of solutions of polyethylene glycol 8000 both in the absence and presence of other solutes. Plant Physiology 72, 66–70.Google Scholar
Ni, B.-R. and Bradford, K.J. (1992) Quantitative models characterizing seed germination responses to abscisic acid and osmoticum. Plant Physiology 98, 1057–1068.CrossRefGoogle ScholarPubMed
Roberts, E.H. (1988) Temperature and seed germination. pp 109–132 in Long, S.P. and Woodward, F.I. (Eds) Plants and temperature. Cambridge, Society for Experimental Biology.Google Scholar
Rowse, H.R., Goodman, D. and Grey, H. (1986) A model of seed germination. National Vegetable Research Station Annual Report 1986, 99–100.Google Scholar
Tarquis, A. and Bradford, K.J. (1992) Prehydration and priming treatments that advance germination also increase the rate of deterioration of lettuce seed. Journal of Experimental Botany 43, 307–317.CrossRefGoogle Scholar
Vertucci, C.W. and Roos, E.E. (1990) Theoretical basis of protocols for seed storage. Plant Physiology 94, 1019–1023.Google Scholar
Wilson, A.M. (1973) Responses of crested wheatgrass seeds to environment. Journal of Range Management 26, 43–46.Google Scholar