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Résumé :
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This book about seeds focuses upon their two most important functions-dormancy and germination. The topics covered include the types of dormancy, theories of the relationship between dormancy and germination, the timing of germination, the various factors that control germination, and the general aspects of germination in different sorts of habitats. Our book differs from others on seed germination in six important ways. It contains a chapter on procedures for doing germination studies so that laboratory and greenhouse results can be extrapolated to the field. Information on many topics (such as dormancy-breaking requirements of seeds with each type of dormancy and genetics of seed dormancy and germination) is placed into an ecological context. A critical evaluation of methodology used in soil seed bank studies of plant communities is presented which shows that many researchers have sampled mixtures of persistent and transient seed banks rather than persistent seed banks only. Data were compiled on species with different life forms growing in the major vegetation types on earth to gain a world perspective on geographical/ecological relationships of the dormancy-breaking and germination requirements of seeds. Data on environmental conditions required to break seed dormancy and stimulate germination have been synthesized for species with specialized life cycles and/or habitats, including parasites, saprophytes, orchids, carnivorous plants, aquatics, halophytes, and psammophytes; this information has been put into an ecological context. For the first time, an attempt has been made to unravel the evolutionary/phylogenetic origins and relationships of the various kinds of seed dormancy and to explain the conditions under which each may have evolved.
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