Plant Variation

Explains how our plant classification system works and looks at how scientists use it to identify and group plant species. The book also examines the variation between and within plants species and discusses how and why such variations have occurred.

Considers how the study of variation in plants has developed over the last 300 years.

We are in the midst of a biological revolution. Molecular tools are now providing new means of critically testing hypotheses and models of microevolution in populations of wild, cultivated, weedy and feral plants. They are also offering the opportunity for significant progress in the investigation of long-term evolution of flowering plants, as part of molecular phylogenetic studies of the Tree of Life. This long-awaited fourth edition, fully revised by David Briggs, reflects new insights provided by molecular investigations and advances in computer science. Briggs considers the implications of these for our understanding of the evolution of flowering plants, as well as the potential for future advances. Numerous new sections on important topics such as the evolutionary impact of human activities, taxonomic challenges, gene flow and distribution, hybridisation, speciation and extinction, conservation and the molecular genetic basis of breeding systems will ensure that this remains a classic text for both undergraduate and graduate students in the field.

Plants produce a considerable number of structures of one kind, like leaves, flowers, fruits, and seeds, and this reiteration is a quintessential feature of the body plan of higher plants. But since not all structures of the same kind produced by a plant are identical—for instance, different branches on a plant may be male or female, leaf sizes in the sun differ from those in the shade, and fruit sizes can vary depending on patterns of physiological allocation among branches—a single plant genotype generally produces a multiplicity of phenotypic versions of the same organ. Multiplicity in Unity uses this subindividual variation to deepen our understanding of the ecological and evolutionary factors involved in plant-animal interactions. On one hand, phenotypic variation at the subindividual scale has diverse ecological implications for animals that eat plants. On the other hand, by choosing which plants to consume, these animals may constrain or modify plant ontogenetic patterns, developmental stability, and the extent to which feasible phenotypic variants are expressed by individuals. An innovative study of the ecology, morphology, and evolution of modular organisms, Multiplicity in Unity addresses a topic central to our understanding of the diversity of life and the ways in which organisms have coevolved to cope with variable environments.

Far from being passive elements in the landscape, plants have developed many sophisticated chemical and mechanical means of deterring organisms that seek to prey on them. This volume draws together research from ecology, evolution, agronomy, and plant pathology to produce an ecological genetics perspective on plant resistance in both natural and agricultural systems. By emphasizing the ecological and evolutionary basis of resistance, the book makes an important contribution to the study of how phytophages and plants coevolve. Plant Resistance to Herbivores and Pathogens not only reviews the literature pertaining to plant resistance from a number of traditionally separate fields but also examines significant questions that will drive future research. Among the topics explored are selection for resistance in plants and for virulence in phytophages; methods for studying natural variation in plant resistance; the factors that maintain intraspecific variation in resistance; and the ecological consequences of within-population genetic variation for herbivorous insects and fungal pathogens. "A comprehensive review of the theory and information on a large, rapidly growing, and important subject."—Douglas J. Futuyma, State University of New York, Stony Brook

Clonality is widespread in plant species, and clonal plants often have a broad geographic range and long lifespan. Clonality can maintain high fitness in the short term, but vegetative reproduction is commonly considered to preclude adaptation to changing conditions. However, an increasing body of empirical and theoretical evidence suggests that epigenetic modifications such as DNA methylation can provide an alternative to gene-driven evolution through natural selection and allow clonal plants to maintain fitness in the long term. To deepen our understanding of clonal ecology, this collection of research papers and reviews focuses on how epigenetic regulation can encode phenotypic plasticity and contribute to the rapid adaptation of clonal plants to accelerating global and regional environmental changes.