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Structural, physiological and molecular aspects of heterogeneity in seeds: a review

Published online by Cambridge University Press:  22 February 2007

Angel Matilla*
Affiliation:
Departamento de Biología Vegetal, Laboratorio de Fisiología Vegetal, Facultad de Farmacia, Universidad de Santiago de Compostela, 15 782-Santiago de Compostela, A Coruña, Spain
Mercedes Gallardo
Affiliation:
Departamento de Biología Vegetal y Ciencias del Suelo, Laboratorio de Fisiología Vegetal, Facultad de Ciencias, Universidad de Vigo, E-36200-Vigo, Pontevedra, Spain
María Isabel Puga-Hermida
Affiliation:
Departamento de Biología Vegetal y Ciencias del Suelo, Laboratorio de Fisiología Vegetal, Facultad de Ciencias, Universidad de Vigo, E-36200-Vigo, Pontevedra, Spain
*
*Correspondence: Fax: +34 981 593 054 Email: bvmatilla@usc.es

Abstract

Higher plants have several strategies to perpetuate themselves under adequate ecophysiological conditions. The production of heterogeneous seeds is one such strategy. That is, to ensure the survival of the next generation, an individual plant might produce seeds that are heterogeneous with respect to the extent of dormancy, dispersion and persistence within the seed bank. Heterogeneity can affect not only certain physiological and molecular properties related to seed germination, but also such characteristics as colour, size and shape, parameters commonly used to differentiate morphs within a heterogeneous seed population. In heterogeneous seeds, the above features determine seed behaviour and alter their mechanism of germination. In this work, emphasis is placed on the existence of seed mutants having major alterations in characteristics of the testa and hormonal response. These mutants constitute a valuable tool for elucidating the mechanism of dormancy, germination and perpetuation of seeds. Finally, ontogeny and heterogeneity are reviewed, providing the first data related to the possible hormonal control of heterogeneity in seeds. These results raise the hypothesis that one of the factors triggering differences in germination among heterogeneous seeds may be an alteration in the signalling and action mechanism of ethylene and abscisic acid (ABA).

Type
Research Review
Copyright
Copyright © Cambridge University Press 2005

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References

Andersson, S. (1996) Seed size as a determinant of germination rate in Crepis tectorum (Asteraceae): evidence from a seed burial experiment. Canadian Journal of Botany 74, 568572.CrossRefGoogle Scholar
Angosto, T. and Matilla, A.J. (1993a) Germination, seed-coat structure and protein patterns of seeds from Adenocarpus decorticans and Astragalus granatensis growing at different altitudes. Seed Science and Technology 21, 317326.Google Scholar
Angosto, T. and Matilla, A.J. (1993b) Variations in seeds of three endemic leguminous species at different altitudes. Physiologia Plantarum 87, 329334.CrossRefGoogle Scholar
Angosto, T. and Matilla, A.J. (1994) Modifications in seeds of Festuca indigesta from two different altitudinal habitats. Seed Science and Technology 22, 319328.Google Scholar
Austenfeld, F.A. (1998) Seed dimorphism in Salicornia europea: nutrient reserves. Physiologia Plantarum 73, 502504.CrossRefGoogle Scholar
Bachmann, K. (1983) Evolutionary genetics and the genetic control of morphogenesis in flowering plants. Evolutionary Biology 16, 157208.CrossRefGoogle Scholar
Bailey, P.C., McKibbin, R.S., Lenton, J.R., Holdsworth, M.J., Flintham, J.E. and Gale, M.D. (1999) Genetic map locations for orthologous Vp1 genes in wheat and rice. Theoretical and Applied Genetics 98, 281284.CrossRefGoogle Scholar
Bakker, J.P., Poschlod, P., Strykstra, R.J., Bekker, R.M. and Thompson, K. (1996) Seed banks and seed dispersal: Important topics in restoration ecology. Acta Botanica Neerlandica 45, 461490.CrossRefGoogle Scholar
Barabé, D. and Jean, R.V. (1996) The constraints of global form on phyllotactic organization: the case of Symplocarpus (Araceae). Journal of Theoretical Biology 178, 393397.CrossRefGoogle Scholar
Baskin, C.C. and Baskin, J.M. (1998) Seeds: Ecology, biogeography and evolution of dormancy and germination. San Diego, Academic Press.Google Scholar
Baskin, J.M. and Baskin, C.C. (2004) A classification system for seed dormancy. Seed Science Research 14, 116.CrossRefGoogle Scholar
Baskin, J.M., Nan, X. and Baskin, C.C. (1998) A comparative study of seed dormancy and germination in an annual and a perennial species of Senna (Fabaceae). Seed Science Research 8, 501512.CrossRefGoogle Scholar
Beaudoin, N., Serizet, C., Gosti, F. and Giraudat, J. (2000) Interactions between abscisic acid and ethylene signaling cascades. Plant Cell 12, 11031115.CrossRefGoogle ScholarPubMed
Bekker, R.M., Bakker, J.P., Grandin, U., Kalamees, R., Milberg, P., Poschlod, P., Thompson, K. and Willems, J.H. (1998) Seed size, shape and vertical distribution in the soil: indicators of seed longevity. Functional Ecology 12, 834842.CrossRefGoogle Scholar
Bell, D.T., Plummer, J.A. and Taylor, S.K. (1993) Seed germination ecology in southwestern Western Australia. Botanical Review 59, 2473.CrossRefGoogle Scholar
Benech-Arnold, R.L., Fenner, M. and Edwards, P.J. (1992) Changes in dormancy level in Sorghum halepense seeds induced by water stress during seed development. Functional Ecology 6, 596605.CrossRefGoogle Scholar
Beneke, K., van Rooyen, M.W., Theron, G.K., van de Venter, H.A. (1993) Fruit polymorphism in ephemeral species of Namaqualand. III. Germination differences between the polymorphic diaspores. Journal of Arid Environments 24, 333344.CrossRefGoogle Scholar
Berger, A. (1985) Seed dimorphism and germination behaviour in Salicornia patula. Vegetatio 61, 137143.CrossRefGoogle Scholar
Bewley, J.D. (1997a) Seed germination and dormancy. Plant Cell 9, 10551066.CrossRefGoogle ScholarPubMed
Bewley, J.D. (1997b) Breaking down the walls – a role for endo-β-mannanase in release from seed dormancy?. Trends in Plant Science 2, 464469.CrossRefGoogle Scholar
Bewley, J.D. and Black, M. (1994) Seeds: Physiology of development and germination (2nd edition) New York PlenumCrossRefGoogle Scholar
Boesewinkel, F.D. and Bouman, F. (1995) The seed: structure and function Seed development and germination 124. Kigel J. Galili G. New York Marcel DekkerCrossRefGoogle Scholar
Brown, N.A.C. and Mitchell, J.J. (1984) Germination of the polymorphic fruits of Bidens bipinnata. South African Journal of Botany 3, 5558.CrossRefGoogle Scholar
Cavers, P.B. and Steel, M.G. (1984) Patterns of change in seed weight over time on individual plants. American Naturalist 124, 324335.CrossRefGoogle Scholar
Cerabolini, B., Ceriani, R.M., Caccianiga, M. De, Andreis, R. and Raimondi, B. (2003) Seed size, shape and persistence in soil: a test on Italian flora from Alps to Mediterranean coasts. Seed Science Research 13, 7585.CrossRefGoogle Scholar
Chaple, C.C.S., Shirley, B.W., Zook, M., Hammerschmidt, R. and Sommerville, S.C. (1994) Secondary metabolism in Arabidopsis pp. 9891030. Meyerowitz, E.M.;, Somerville, C.R.Arabidopsis. Cold Spring Harbor, NY, Cold Spring Harbor Laboratory Press.Google Scholar
Cheplick, G.P. and Sung, L.Y. (1998) Effect of maternal nutrient environment and maturation position on seed heteromorphism, germination, and seedling growth in Triplasis purpurea (Poaceae). International Journal of Plant Sciences 159, 338350.CrossRefGoogle Scholar
Chmielewski, J.G. (1999) Consequences of achene biomass, within-achene allocation patterns, and pappus on germination in ray and disc achenes of Aster umbellatus var. umbellatus (Asteraceae). Canadian Journal of Botany 77, 426433.CrossRefGoogle Scholar
Chmielewski, J.G., Semple, J.C., Burr, L.M. and Hawthorn, W.R. (1989) Comparison of achene characteristics within and among diploid and tetraploid clones of Solidago flexicaulis and their significance in germination and resource allocation studies. Canadian Journal of Botany 67, 18211832.CrossRefGoogle Scholar
Cook, A.D., Atsatt, P.R. and Simon, C.A. (1971) Doves and dove weed: multiple defenses against avian predation. BioScience 21, 277281.CrossRefGoogle Scholar
Corbineau, F., Côme, D. (1995) Control of seed germination and dormancy by the gaseous environment. pp. 397424. in Kigel, J.;, Galili, G.Seed development and germination. New York, Marcel Dekker.Google Scholar
Coste, F., Ney, B. and Crozart, Y. (2001) Seed development and seed physiological quality of field grown beans (Phaseolus vulgaris L.). Seed Science and Technology 29, 121136.Google Scholar
Couvillon, G.A. (2002) Cercis canadensis L. seed size influences germination rate, seedling dry matter, and seedling leaf area. HortScience 37, 206207.CrossRefGoogle Scholar
de Clavijo, E.R. (1994) Heterocarpy and seed polymorphism in Ceratocapnos heterocarpa (Fumariaceae). International Journal of Plant Science 155, 196202.CrossRefGoogle Scholar
Debeaujon, I. and Koornneef, M. (2000) Gibberellin requirement for Arabidopsis seed germination is determined both by testa characteristics and embryonic abscisic acid. Plant Physiology 122, 415424.CrossRefGoogle ScholarPubMed
Debeaujon, I., Leon-Kloosterziel, K.M. and Koornneef, M. (2000) Influence of the testa on seed dormancy, germination and longevity in Arabidopsis. Plant Physiology 122, 403413.CrossRefGoogle ScholarPubMed
Doucet, C. and Cavers, P.B. (1997) Induced dormancy and colour polymorphism in seeds of the bull thistle Cirsium vulgare (Savi) Ten. Seed Science Research 7, 399407.CrossRefGoogle Scholar
Egli, D.B. (1998) Seed biology and the yield of grain crops. Wallingford, CAB International.Google Scholar
Fenner, M. (1993) Environmental influences of seed size and composition. Horticultural Reviews 13, 183213.Google Scholar
Flintham, J.E. (2000) Different genetic components control coat-imposed and embryo-imposed dormancy in wheat. Seed Science Research 10, 4350.CrossRefGoogle Scholar
Funes, G., Basconcelo, S., Diaz, S. and Cabido, M. (1999) Seed size and shape are good predictors of seed persistence in soil in temperate mountain grasslands of Argentina. Seed Science Research 9, 341345.CrossRefGoogle Scholar
Gardocki, M.E., Zablocki, H., El-Keblawy, A. and Freeman, D.C. (2000) Heterocarpy in Calendula micrantha (Asteraceae): The effects of competition and availability of water on the performance of offspring from different fruit morphs. Evolutionary Ecology Research 2, 701718.Google Scholar
Grappin, P., Bouinot, D., Sotta, B., Miginiac, E. and Jullien, M. (2000) Control of seed dormancy in Nicotiana plumbaginifolia: Post-imbibition abscisic acid synthesis imposes dormancy maintenance. Planta 210, 279285.CrossRefGoogle ScholarPubMed
Groot, S.P.C. and Karssen, C.M. (1992) Dormancy and germination of abscisic acid-deficient tomato seeds: Studies with the sitiens mutant. Plant Physiology 99, 952958.CrossRefGoogle ScholarPubMed
Grossmann, K. and Hansen, H. (2001) Ethylene-triggered abscisic acid: a principle in plant growth regulation?. Physiologia Plantarum 113, 914.CrossRefGoogle Scholar
Grotewold, E., Drummond, B.J., Bowen, B. and Peterson, T. (1994) The myb -homologous P gene controls phlobaphene pigmentation in maize floral organs by directly activating a flavonoid biosynthetic gene subset. Cell 76, 543553.CrossRefGoogle ScholarPubMed
Gutterman, Y. (1980/1981) Annual rhythm and position effect in the germinability of Mesembryanthemum nodiflorum Israel Journal of Botany 29, 9397.Google Scholar
Gutterman, Y. (1992) Maternal effects on seeds during development. pp. 2759. Fenner, M. (Ed.) Seeds. The ecology of regeneration in plant communities. Wallingford, CAB International.Google Scholar
Gutterman, Y. (1994a) Long-term seed position influences on seed germinability of the desert annual, Mesembryanthemum nodiflorum L. Israel Journal of Plant Sciences 42, 197205.CrossRefGoogle Scholar
Gutterman, Y. (1994b) Strategies of seed dispersal and germination in plants inhabiting deserts. Botanical Review 60, 373425.CrossRefGoogle Scholar
Hacker, J.B. and Ratcliffe, D. (1989) Seed dormancy and factors controlling dormancy breakdown in buffel grass accessions from contrasting provenances. Journal of Applied Ecology 26, 201212.CrossRefGoogle Scholar
Harris, W.M. (1987) Comparative ultrastructure of developing seed coats of ‘hard-seeded’ and ‘soft-seeded’ varieties of soybean, Glycine max (L.). Merr. Botanical Gazette 148, 324331.CrossRefGoogle Scholar
Hendry, G.A.F., Thompson, K., Moss, C.J., Edwards, E. and Thorpe, P.C. (1994) Seed persistence: a correlation between seed longevity in the soil and ortho-dihydroxyphenol concentration. Functional Ecology 8, 658664.CrossRefGoogle Scholar
Hilhorst, H.W.M. (1995) A critical update on seed dormancy. I. Primary dormancy. Seed Science Research 5, 6173.CrossRefGoogle Scholar
Hilhorst, H.W.M. and Downie, B. (1995) Primary dormancy in tomato (Lycopersicon esculentum cv. Moneymaker): studies with the sitiens mutant. Journal of Experimental Botany 47, 8997.CrossRefGoogle Scholar
Hilhorst, H.W.M. and Toorop, P.E. (1997) Review on dormancy, germinability, and germination in crop and weed seeds. Advances in Agronomy 61, 111165.CrossRefGoogle Scholar
Himi, E., Mares, D.J., Yanagisawa, A. and Noda, K. (2002) Effect of grain colour gene ( R ) on grain dormancy and sensitivity of the embryo to abscisic acid (ABA) in wheat. Journal of Experimental Botany 53, 15691574.CrossRefGoogle ScholarPubMed
Hocking, P.J. (1982) Salt and mineral nutrient levels in fruits of two strand species, Cakile maritima and Arctotheca populifolia, with special reference to the effect of salt on the germination of Cakile. Annals of Botany 50, 335343.Google Scholar
Hodkinson, D.J., Askew, A.P., Thompson, K., Hodgson, J.G., Bakker, J.P. and Bekker, R.M. (1998) Ecological correlates of seed size in the British flora. Functional Ecology 12, 762766.CrossRefGoogle Scholar
Holdsworth, M., Kurup, S. and McKibbin, R. (1999) Molecular and genetic mechanisms regulating the transition from embryo development to germination. Trends in Plant Science 4, 275280.CrossRefGoogle Scholar
Huang, G., McCrate, A.J., Varriano-Marston, E. and Paulsen, G.M. (1983) Caryopsis structural and imbibitional characteristics of some hard red and white wheats. Cereal Chemistry 60, 161165.Google Scholar
Hulme, P.E. (1998) Post-dispersal seed predation and seed bank persistence. Seed Science Research 8, 513519.CrossRefGoogle Scholar
Imbert, E. (1999) The effects of achene dimorphism on the dispersal in time and space in Crepis sancta (Asteraceae). Canadian Journal of Botany 77, 508513.CrossRefGoogle Scholar
Imbert, E. (2001) Capitulum characters in the seed heteromorphic species, Crepis sancta (Asteraceae): variance partitioning and inference for the evolution of dispersal rate. Heredity 86, 7886.CrossRefGoogle Scholar
Imbert, E. (2002) Ecological consequences and ontogeny of seed heteromorphism. Perspectives in Plant Ecology, Evolution and Systematics 5, 1336.CrossRefGoogle Scholar
Imbert, E., Escarre, J. and Lepart, J. (1999) Differentiation among populations for life history, morphology, head traits and achene morph proportions in the heterocarpic species Crepis sancta (L.) Bornm. International Journal of Plant Sciences 160, 543552.CrossRefGoogle Scholar
Jaimand, K. and Rezaee, M.B. (1996) Variability in seed composition due to plant population and capitula zones of sunflower. Agrochimica 40, 4854.Google Scholar
Kawakami, N., Miyake, Y. and Noda, K. (1997) ABA insensitivity and low ABA levels during seed development of non-dormant wheat mutants. Journal of Experimental Botany 48, 14151421.CrossRefGoogle Scholar
Kelly, K.M., van Staden, J. (1985) Effect of acid scarification on seed coat structure, germination and seedling vigor of Aspalathus linearis. Journal of Plant Physiology 121, 3745.CrossRefGoogle Scholar
Kende, H., Van der Knaap, E. and Cho, H.T. (1998) Deepwater rice: A model plant to study stem elongation. Plant Physiology 118, 11051110.CrossRefGoogle Scholar
Khan, M.A. and Ungar, I.A. (2001) Alleviation of salinity stress and the response to temperature in two seed morphs of Halopyrum mucronatum (Poaceae). Australian Journal of Botany 49, 777783.CrossRefGoogle Scholar
Khan, M., Cavers, P.B., Kane, M. and Thompson, K. (1996) Role of the pigmented seed coat of proso millet (Panicum miliaceum L.) in imbibition, germination and seed persistence. Seed Science Research 7, 2125.CrossRefGoogle Scholar
Kigel, J. (1995) Seed germination in arid and semiarid regions. pp. 645700. in Kigel, J.;, Galili, G. (Eds) Seed development and germination. New York, Marcel Dekker.Google Scholar
Koller, D. (1972) Environmental control of seed germination. pp. 1101. in Kozlowski, T.T.Seed biology, Vol. 2, London, Academic Press.Google Scholar
Koornneef, M., Bentsink, L. and Hilhorst, H. (2002) Seed dormancy and germination. Current Opinion in Plant Biology 5, 3336.CrossRefGoogle ScholarPubMed
Kuang, A., Xiao, Y. and Musgrave, M.E. (1996) Cytochemical localization of reserves during seed development in Arabidopsis thaliana under spaceflight conditions. Annals of Botany 78, 343351.CrossRefGoogle ScholarPubMed
Legesse, N. and Powell, A.A. (1992) Comparisons of water uptake and imbibition damage in eleven cowpea cultivars. Seed Science and Technology 20, 173180.Google Scholar
Leishman, M.R. and Westoby, M. (1998) Seed size and shape are not related to persistence in soil in Australia in the same way as in Britain. Functional Ecology 12, 480485.CrossRefGoogle Scholar
Léon-Kloosterziel, K.M., Keijzer, C.J. and Koornneef, M. (1994) A seed shape mutant of Arabidopsis that is affected in integument development. Plant Cell 6, 385392.CrossRefGoogle ScholarPubMed
Leubner-Metzger, G. (2003) Hormonal and molecular events during seed dormancy release and germination. pp. 101112. in Nicolás, G.;, Bradford, K.J.;, Côme, D.;, Pritchard, H.W.The biology of seeds: Recent research advances. Wallingford, CABI Publishing.Google Scholar
Lijavetzky, D., Martínez, M.C., Carrari, F. and Hopp, H.E. (2000) QTL analysis and mapping of pre-harvest sprouting resistance in sorghum. Euphytica 112, 125135.CrossRefGoogle Scholar
Lloyd, A.M., Walbot, V. and Davis, R.W. (1992) Arabidopsis and Nicotiana anthocyanin production activated by maize regulators R and C1. Science 258, 17731775.CrossRefGoogle ScholarPubMed
Lloyd, D.G. (1984) Variation strategies of plants in heterogeneous environments. Biological Journal of the Linnean Society 21, 357385.CrossRefGoogle Scholar
Lokker, C. and Cavers, P.B. (1995) The effects of physical damage on seed production in flowering plants of Saponaria officinalis. Canadian Journal of Botany 73, 235243.CrossRefGoogle Scholar
Mandak, B. (1997) Seed heteromorphism and the life cycle of plants: A literature review. Preslia-Prague 69, 129159.Google Scholar
Manning, J.C., van Staden, J. (1985) The development and the ultrastucture of the testa and tracheid bar in Erythrina lysistemon Hutch. Protoplasma 129, 157167.CrossRefGoogle Scholar
Manning, J.C., van Staden, J. (1987) The role of the lens in seed imbibition and seedling vigor of Sesbania punicea (Cav.) Benth. (Leguminosae: Papilionoideae). Annals of Botany 59, 705713.Google Scholar
Maranon, T. (1989) Variations in seed size and germination in three Aegilops species. Seed Science and Technology 17, 583588.Google Scholar
Maun, M.A. and Payne, A.M. (1989) Fruit and seed polymorphism and its relation to seedling growth in the genus Cakile. Canadian Journal of Botany 67, 27432750.CrossRefGoogle Scholar
Maxwell, C.D., Zobel, A. and Woodfine, D. (1994) Somatic polymorphism in the achenes of Tragopogon dubius. Canadian Journal of Botany 72, 12821288.CrossRefGoogle Scholar
McCarty, D.R. (1995) Genetic control and integration of maturation and germination pathways in seed development. Annual Review of Plant Physiology and Molecular Biology 46, 7193.CrossRefGoogle Scholar
McDonald, A.W., Bakker, J.P. and Vegelin, K. (1996) Seed bank classification and its importance for the restoration of species-rich flood-meadows. Journal of Vegetation Science 7, 157164.CrossRefGoogle Scholar
McDonough, W.T. (1975) Germination polymorphism in Grindelia squarrosa. Northwest Science 49, 190200.Google Scholar
McEvoy, P.B. (1984) Dormancy and dispersal in dimorphic achenes of tansy ragwort, Senecio jacobaea L. (Compositae). Oecologia 61, 160168.CrossRefGoogle ScholarPubMed
McGinley, M.A. (1989) Within and among plant variation in seed mass and pappus size in Tragopogon dubios. Canadian Journal of Botany 67, 12981304.CrossRefGoogle Scholar
McKibbin, R.S., Bailey, P.C., Flintham, J.E., Gale, M.D., Lenton, J.R. and Holdsworth, M.J. (1999) Molecular analysis of the wheat VIVIPAROUS 1 (VP1) orthologue. pp. 113118. in Weipert, D. (Ed.) Eighth international symposium on preharvest sprouting in cereals: 1998. Detmold, Germany, Association of Cereal Research.Google Scholar
Meinke, D.W. (1994) Seed development in A. thaliana Arabidopsis pp. 253295. in Meyerowitz, E.M.;, Somerville, C.R. (Eds). Cold Spring Harbor, NY, Cold Spring Harbor Laboratory Press.Google Scholar
Meisert, A., Schulz, D. and Lehmann, H. (1999) Structural features underlying hardseededness in Geraniaceae. Plant Biology 1, 311314.CrossRefGoogle Scholar
Meisert, A., Schulz, D. and Lehmann, H. (2001) The ultrastructure and development of the light line in the Geraniaceae seed coat. Plant Biology 3, 351356.CrossRefGoogle Scholar
Michaels, H.J., Wilson, M.F., Bertin, R.I., Benner, B., Hartgerink, A.P., Lee, T.D. and Rice, S. (1988) Seed size variation: Magnitude, distribution and ecological correlates. Evolutionary Ecology 2, 157166.CrossRefGoogle Scholar
Milberg, P., Andersson, L. and Thompson, K. (2000) Large-seeded species are less dependent on light for germination than small-seeded ones. Seed Science Research 10, 99104.CrossRefGoogle Scholar
Moles, A.T., Hodson, D.W. and Webb, C.J. (2000) Seed size and shape and persistence in the soil in the New Zealand flora. Oikos 89, 541545.CrossRefGoogle Scholar
Oliveira, M. De, A. Matthews, S. and Powell, A.A. (1984) The role of split seed coats in determining seed vigor in commercial seed lots of soybean, as measured by the electrical conductivity test. Seed Science and Technology 12, 659668.Google Scholar
Patrick, J.W. and Offler, C.E. (2001) Compartmentation of transport and transfer events in developing seeds. Journal of Experimental Botany 52, 551564.CrossRefGoogle ScholarPubMed
Peco, B., Traba, J., Levassor, C., Sánchez, A.M. and Azcarate, F.M. (2003) Seed size, shape and persistence in dry Mediterranean grass and scrublands. Seed Science Research 13, 8795.CrossRefGoogle Scholar
Picciarelli, P., Piaggesi, A. and Lorenzi, R. (1994) ABA metabolite levels in developing embryos of Sechium edule. Advances in Horticultural Science 8, 201204.Google Scholar
Powell, A.A. (1989) The importance of genetically determined seed coat characteristics to seed quality in grain legumes. Annals of Botany 63, 169175.CrossRefGoogle Scholar
Powell, A.A. and Matthews, S. (1978) The damaging effect of water on dry pea embryos during imbibition. Journal of Experimental Botany 29, 12151229.CrossRefGoogle Scholar
Powell, A.A. and Matthews, S. (1980) The significance of damage during imbibition to the field emergence of pea (Pisum sativum L.) seed. Journal of Agriculture Science 95, 3538.CrossRefGoogle Scholar
Powell, A.A., Oliveira, M. De, A. Matthews, S. (1986a) The role of imbibition damage in determining the vigour of white and coloured seed lots of dwarf French beans (Phaseolus vulgaris). Journal of Experimental Botany 57, 716722.CrossRefGoogle Scholar
Powell, A.A., Oliveira, M. De, A. Matthews, S. (1986b) Seed vigour in cultivars of dwarf French bean ( Phaseolus vulgaris ) in relation to the colour of the testa. Journal of Agriculture Science 106, 419425.CrossRefGoogle Scholar
Prinzie, T.P. and Chmielewski, J.G. (1994) Significance of achene characteristics and within-achene resource allocation in the germination strategy of tetraploid Aster pilosus var. pilosis (Asteraceae). American Journal of Botany 81, 259264.Google Scholar
Puga-Hermida, M.I. (2003) The embryogenesis and germination of turnip tops seeds provokes important alterations in the ethylene production and ABA and polyamine levels. PhD Thesis, University of Vigo, Pontevedra, Spain.Google Scholar
Puga-Hermida, M.I., Gallardo, M., Rodríguez-Gacio, M.C. and Matilla, A.J. (2003a) The heterogeneity of turnip-tops (Brassica rapa) seeds inside the silique affects germination, the activity of the final step of the ethylene pathway, and abscisic acid and polyamine content. Functional Plant Biology 30, 767775.CrossRefGoogle ScholarPubMed
Puga-Hermida, M.I., Gallardo, M. and Matilla, A.J. (2003b) The zygotic embryogenesis and ripening of Brassica rapa seeds provokes important alterations in the levels of free and conjugated abscisic acid and polyamines. Physiologia Plantarum 117, 279288.CrossRefGoogle Scholar
Ramsay, G. (1997) Inheritance and linkage of a gene for testa-imposed seed dormancy in faba bean (Vicia faba L.). Plant Breeding 116, 287289.CrossRefGoogle Scholar
Ren, C.W. and Bewley, J.D. (1998) Seed development, testa structure and precocious germination of Chinese cabbage (Brassica rapa subsp. pekinensis). Seed Science Research 8, 385397.CrossRefGoogle Scholar
Roberts, J.A., Elliot, K.A., González-Carranza, Z.H. (2002) Abscission, dehiscence, and other cell separation processes. Annual Review of Plant Biology 53, 131158.CrossRefGoogle ScholarPubMed
Rocha, O.J. (1996) The effects of achene heteromorphism on the dispersal capacity of Bidens pilosa L. International Journal of Plant Sciences 157, 316322.CrossRefGoogle Scholar
Rodríguez-Gacio, M.C., Nicolás, C. and Matilla, A.J. (2004) The final step of the ethylene biosynthesis pathway in turnip tops (Brassica rapa L. cv. Rapa): Molecular characterization of the 1-aminocyclopropane-1-carboxylate oxidase BrACO1 throughout zygotic embryogenesis and germination of heterogeneous seeds. Physiologia Plantarum 121, 132140.CrossRefGoogle Scholar
Sakai, S. and Sakai, A. (1996) Why is there variation in mean seed size among plants within single populations? Test of the fertilization efficiency hypothesis. American Journal of Botany 83, 14541457.CrossRefGoogle Scholar
Simons, A.M. and Johnston, M.O. (1997) Developmental instability as a bet-hedging strategy. Oikos 80, 401406.CrossRefGoogle Scholar
Simons, A.M. and Johnston, M.O. (2000) Variation in seed traits of Lobelia inflata (Campanulaceae): sources and fitness consequences. American Journal of Botany 87, 124132.CrossRefGoogle ScholarPubMed
Spence, J., Vercher, Y., Gates, P. and Harris, N. (1996) ‘Pod shatter‘ in Arabidopsis thaliana, Brassica napus and B. juncea. Journal of Microscopy 181, 195203.CrossRefGoogle Scholar
Steber, C.M., Cooney, S.E. and McCourt, P. (1998) Isolation of the GA-response mutant sly1 as a suppressor of ABI1–1 in Arabidopsis thaliana. Genetics 149, 509521.CrossRefGoogle ScholarPubMed
Susko, D.J., Lovett-Doust, L. (1998) Variable patterns of seed maturation and abortion in Alliaria petiolata (Brassicaceae). Canadian Journal of Botany 76, 16771686.CrossRefGoogle Scholar
Susko, D.J., Lovett-Doust, L. (2000) Patterns of seed mass variation and their effects on seedling traits in Alliaria petiolata (Brassicaceae). American Journal of Botany 87, 5666.CrossRefGoogle ScholarPubMed
Takeno, K. and Yamaguchi, H. (1991) Diversity in seed germination behavior in relation to heterocarpy in Salsola komarovii Iljin. The Botanical Magazine 104, 207215.CrossRefGoogle Scholar
Tanowitz, B.D., Salopek, P.F. and Mahall, B.E. (1987) Differential germination of ray and disk achenes in Hemizonia increscens (Asteraceae). American Journal of Botany 74, 303312.CrossRefGoogle Scholar
Telenius, A. (1992) Seed heteromorphism in a population of Spergularia media in relation to the ambient vegetation density. Acta Botanica Neerlandica 41, 305318.CrossRefGoogle Scholar
Thompson, K., Band, S.R. and Hodgson, J.G. (1993) Seed size and shape predict persistence in soil. Functional Ecology 7, 236241.CrossRefGoogle Scholar
Thompson, K., Jalili, A., Hodgson, J.G., Hamzehée, B., Asri, Y., Shaw, S., Shirvany, A., Yazdani, S., Khoshnevis, M., Zarrinkamar, F., Ghahramani, M. and Safavi, R. (2001) Seed size, shape and persistence in the soil in an Iranian flora. Seed Science Research 11, 345355.Google Scholar
Thompson, K., Ceriani, R.M., Bakker, J.P. and Bekker, R.M. (2003) Are seed dormancy and persistence in soil related?. Seed Science Research 13, 97100.CrossRefGoogle Scholar
Torres-Ruiz, R.A. (1998) Embryogenesis Arabidopsis. pp. 223261. in Anderson, M.;, Roberts, J.A. (Eds) Annual plant reviews, Vol. 1, Boca Raton, Florida CRC Press.Google Scholar
Venable, D.L. (1985) The evolutionary ecology of seed heteromorphism. American Naturalist 126, 577595.CrossRefGoogle Scholar
Venable, D.L. and Burquez, A. (1989) Quantitative genetics of size, shape, life history, and fruit characteristics of the seed-heteromorphic composite Heterosperma pinnatum. I. Variation within and among populations. Evolution 43, 113124.Google ScholarPubMed
Venable, D.L. and Levin, D.A. (1985) Ecology of achene dimorphism in Heterotheca latifolia. 1. Achene structure, germination and dispersal. Journal of Ecology 73, 133145.CrossRefGoogle Scholar
Venable, D.L., Burquez, A., Corral, G., Morales, E. and Espinosa, F. (1987) The ecology of seed heteromorphism in Heterosperma pinnatum in Central Mexico. Ecology 68, 6576.CrossRefGoogle Scholar
Venable, D.L., Dyreson, E. and Morales, E. (1995) Population dynamic consequences and evolution of seed traits of Heterosperma pinnatum (Asteraceae). American Journal of Botany 82, 410420.CrossRefGoogle Scholar
Walck, J.L., Baskin, J.M. and Baskin, C.C. (1997) A comparative study of the seed germination biology of a narrow endemic and two geographically-widespread species of Solidago (Asteraceae). 1. Germination phenology and effect of cold stratification on germination. Seed Science Research 7, 4758.CrossRefGoogle Scholar
Warner, R.L., Kudrna, D.A., Spaeth, S.C. and Jones, S.S. (2000) Dormancy in white-grain mutants of Chinese spring wheat (Triticum aestivum L.). Seed Science Research 10, 5160.CrossRefGoogle Scholar
Weiss, P.W. (1980) Germination, reproduction and interferences in the amphicarpic annual Emex spinosa (L.) Campd. Oecologia 45, 244251.CrossRefGoogle ScholarPubMed
Wells, C.L. and Pigliucci, M. (2000) Adaptative phenotypic plasticity, the case of heterophylly in aquatic plants. Perspectives in Plant Ecology, Evolution and Systematics 3, 118.CrossRefGoogle Scholar
Westoby, M., Jurado, E. and Leishman, M.R. (1992) Comparative evolutionary ecology of seed size. Trends in Ecology and Evolution 7, 368372.CrossRefGoogle ScholarPubMed
Westoby, M., Leishman, M.R. and Lord, J. (1996) Comparative ecology of seed size and dispersal. Philosophical Transactions of the Royal Society of London, Series B 351, 13091318.Google Scholar
Williams, C.M. and Harper, J.L. (1965) Seed dimorphism and germination. I. The influence of nitrates and low temperatures on the germination of Chenopodium album. Weed Research 5, 141150.CrossRefGoogle Scholar
Wolfe, L.M. (1995) The genetics and ecology of seed size variation in a biennial plant, Hydrophyllum appendiculatum (Hydrophyllaceae). Oecologia 101, 343352.CrossRefGoogle Scholar
Wurzburger, J. and Koller, D. (1976) Differential effects of the parental photothermal environment on development of dormancy in caryopses of Aegilops kotschyi. Journal of Experimental Botany 27, 4348.CrossRefGoogle Scholar
Zhang, J. (1993) Seed dimorphism in relation to germination and growth of Cakile edentula. Canadian Journal of Botany 71, 12311235.CrossRefGoogle Scholar
Zhang, J. (1994) Early seedling development in relation to seed mass and morph in Cakile edentula. Canadian Journal of Botany 72, 402406.CrossRefGoogle Scholar
Zhang, J. (1995) Differences in phenotypic plasticity between plants from dimorphic seeds of Cakile edentula. Oecologia 102, 353360.CrossRefGoogle ScholarPubMed