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Using hydrothermal time concepts to model seed germination response to temperature, dormancy loss, and priming effects in Elymus elymoides

  • Susan E. Meyer (a1), Susan B. Debaene-Gill (a2) and Phil S. Allen (a2)
Abstract
Abstract

Hydrothermal time (HTT) describes progress toward seed germination under various combinations of incubation water potential ( ) and temperature (T). To examine changes in HTT parameters during dormancy loss, seeds from two populations of the bunchgrass Elymus elymoides were incubated under seven temperature regimes following dry storage at 10, 20 and 30°C for intervals from 0 to 16 weeks. Fully after-ripened seeds were primed for 1 week at a range of s. Data on germination rate during priming were used to obtain a HTT equation for each seed population, while data obtained following transfer to water were used to calculate HTT accumulation during priming. HTT equations accurately predicted germination time course curves if mean base water potential, b(50), was allowed to vary with temperature. b(50) values increased linearly with temperature, explaining why germination rate does not increase with temperature in this species. b(50) showed a linear decrease as a function of thermal time in storage. Slopes for the T × b(50) relationship did not change during after-ripening. This thermal after-ripening time model was characterized by a single base temperature and a constant slope across temperatures for each collection. Because the difference between initial and final b(50)s was uniform across tempera-tures, the thermal after-ripening requirement was also a constant. When seeds were primed for 1 week at −4 to −20 MPa, accumulation of HTT was a uniform 20% of the total HTT requirement. When primed at 0 to −4 MPa, HTT accumulation decreased linearly with decreasing priming potential, and a hydrothermal priming time model using a constant minimum priming potential adequately described priming effects. Use of these simple HTT relationships will facilitate modelling of germination phenology in the field.

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*Correspondence Fax: + 1 (801) 375 6968 Email: semeyer@sisna.com
References
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Allen P.S. and Meyer S.E. (1998) Ecological aspects of seed dormancy loss. Seed Science Research 8, 183191.
Allen P.S., White D.B., Russer K. and Olson G. (1992) A method for controlling water potential in seed germination research. HortScience 27, 364366.
Allen P.S., Debaene S.B.G. and Meyer S.E. (1993a) Regulation of grass seed germination under fluctuating moisture regimes. pp. 387–392 in Côme D., Corbineau F. (Eds) Proceedings of the fourth international workshop on seeds.ParisASFIS.
Allen P.S., White D.B. and Markhart A.H. (1993b) Germination of perennial ryegrass and annual bluegrass seeds subjected to hydration–dehydration cycles. Crop Science 33, 10201025.
Allen P.S., Meyer S.E. and Khan M.A. (2000) Hydrothermal time as a tool in comparative germination studies. pp. 401410in Black M.; Bradford K.J.; Vazquez-Ramos J. (Eds) Seed biology: advances and applications, Wallingford, CAB International.
Anonymous (1998) Rules for testing seeds. Lincoln, NE, Association of Official Seed Analysts.
Bauer M.C., Meyer S.E. and Allen P.S. (1998) A simulation model to predict seed dormancy loss in the field for Bromus tectorum L. Journal of Experimental Botany 49, 12351244.
Beckstead J., Meyer S.E. and Allen P.S. (1995) Effects of after-ripening on cheatgrass (Bromus tectorum) and squirreltail (Elymus elymoides) germination. pp. 165–172 in Roundy B.A.; McArthur E.D.; Haley J.S.; Mann D.K. (Compilers) Proceedings: Wildland shrub and arid land restoration symposium.USDA Forest Service General Technical Report INT-GTR-315, Ogden, UT, USDA.
Bradford K.J. (1990) A water relations analysis of seed germination rates. Plant Physiology 94, 840849.
Bradford K.J. (1995) Water relations in seed germination. pp. 351396 in Kigel J.; Galili G. (Eds) Seed development and germination. New York, Marcel Dekker.
Bradford K.J. and Haigh A.M. (1994) Relationship between accumulated hydrothermal time during seed priming and subsequent seed germination rates. Seed Science Research 4, 6369.
Cheng Z.Y. and Bradford K.J. (1999) Hydrothermal time analysis of tomato seed germination responses to priming treatments. Journal of Experimental Botany 50, 8999.
Christensen M., Meyer S.E. and Allen P.S. (1996) A hydrothermal time model of seed after-ripening in Bromus tectorum L. Seed Science Research 6, 155163.
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, 7180.
Dahal P., Bradford K.J. and Haigh A.M. (1993) The concept of hydrothermal time in seed germination and priming. pp. 10091014 in Côme D.; Corbineau F. (Eds) Proceedings of the fourth international workshop on seeds: basic and applied aspects of seed biology. Paris, ASFIS.
Debaene-Gill S.B., Allen P.S. and White D.B. (1994) Dehydration of germinating perennial ryegrass seeds can alter rate of subsequent radicle emergence. Journal of Experimental Botany 45, 13011307.
Dutta S. and Bradford K.J. (1994) Water relations of lettuce seed thermoinhibition. II. Ethylene and endosperm effects on base water potential. Seed Science Research 4, 1118.
Ellis R.H., Covell S., Roberts E.H. and Summerfield R.J. (1986) The influence of temperature on seed germination rate in grain legumes. II. Intraspecific variation in chickpea at constant temperatures. Journal of Experimental Botany 37, 15031515.
Gummerson R.J. (1986) The effect of constant temperatures and osmotic potentials on the germination of sugar beet. Journal of Experimental Botany 37, 729741.
Hardegree S.P. and Emmerich W.E. (1990) Partitioning water potential and specific salt effects on seed germination of four grasses. Annals of Botany 66, 587595.
Meyer S.E. and Monsen S.B. (1991) Habitat-correlated variation in mountain big sagebrush (Artemisia tridentata ssp. vaseyana) seed germination patterns. Ecology 72, 739742.
Meyer S.E., McArthur E.D. and Jorgensen G.R. (1989) Variation in germination response to temperature in rubber rabbitbrush (Chrysothamnus nauseosus: Asteraceae) and its ecological implications. American Journal of Botany 76, 981991.
Meyer S.E., Kitchen S.G. and Carlson S.L. (1995) Seed germination timing patterns in Intermountain Penstemon. American Journal of Botany 82, 377389.
Ni B.R. and Bradford K.J. (1992) Quantitative models characterizing seed germination responses to abscisic acid and osmoticum. Plant Physiology 98, 10571068.
Ni B.R. and Bradford K.J. (1993a) Germination and dormancy of abscisic acid- and gibberellin-deficient mutant tomato (Lycopersicon esculentum) seeds. Sensitivity of germination to abscisic acid, gibberellin and water potential. Plant Physiology 101, 607617.
Ni B.R. and Bradford K.J. (1993b) Sensitivity of ABA- and GA-deficient mutant tomato seeds to ABA, GA and water potential. pp. 555560 in Côme D.; Corbineau F. (Eds) Proceedings of the fourth international workshop on seeds: basic and applied aspects of seed biology. Paris, ASFIS.
Rowse H.R., McKee J.M.T. and Higgs E.C. (1999) A model of the effects of water stress on seed advancement and germination. New Phytologist 143, 273279.
Saleki R., Young P.G. and Lefebvre D.D. (1993) Mutants of Arabidopsis thaliana capable of germination under saline conditions. Plant Physiology 101, 839845.
SAS Institute (1990) SAS procedures guide version six (3rd edition). Cary, NC, SAS Institute Inc.
Tarquis A.M. and Bradford K.J. (1992) Prehydration and priming treatments that advance germination also increase the rate of deterioration of lettuce seeds. Journal of Experimental Botany 43, 307317.
Taylor A.G., Allen P.S., Bennett M.A., Bradford K.J., Burris J.S. and Misra M.K. (1998) Seed enhancements. Seed Science Research 8, 245256.
Vertucci C.W. (1989) The effects of low water contents on physiological activities of seeds. Physiologia Plantarum 77, 172176.
Vertucci C.W. and Farrant J.M. (1995) Acquisition and loss of desiccation tolerance. pp. 237272 in Kigel J.; Galili G. (Eds) Seed development and germination. New York, Marcel Dekker.
Vertucci C.W. and Leopold A.C. (1984) Bound water in soybean seed and its relation to respiration and imbibitional leakage. Plant Physiology 75, 114117.
Welbaum G.E., Tissaoui T. and Bradford K.J. (1990) Water relations of seed development and germination in muskmelon (Cucumis melo L.). III. Sensitivity of germination to water potential and abscisic acid during development. Plant Physiology 92, 10291037.
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Seed Science Research
  • ISSN: 0960-2585
  • EISSN: 1475-2735
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