Charles E. Hess Department of Environmental Horticulture University of California Davis, CA 95616 Research in the biology of adventitious root formation has a special place in science. It provides an excellent forum in which to pursue fundamental research on the regulation of plant growth and development. At the same time the results of the research have been quickly applied by commercial plant propagators, agronomists, foresters and horticulturists (see the chapter by Kovar and Kuchenbuch, by Ritchie, and by Davies and coworkers in this volume). In an era when there is great interest in speeding technology transfer, the experiences gained in research in adventitious root formation may provide useful examples for other areas of science. Interaction between the fundamental and the applied have been and continue to be facilitated by the establishment, in 1951, of the Plant Propagators' Society, which has evolved into the International Plant Propagators' Society, with active programs in six regions around the world. It is a unique organization which brings together researchers in universities, botanical gardens and arboreta, and commercial plant propagators. In this synergistic environment new knowledge is rapidly transferred and new ideas for fundamental research evolve from the presentations and discussions by experienced plant propagators. In the past 50 years, based on research related to the biology of adventitious root formation, advances in plant propagation have been made on two major fronts.

This book contains the majority of the presentations of the Second International Symposium on the Biology of Root Formation and Development that was hcld in Jerusa lem, Israel, June 23---28, 1996. Following the First Symposium on the Biology of Adventi tious Root Formation, held in Dallas. USA, 1993, we perceived the need to include all kinds of roots, not only the shoot-borne ones. The endogenous signals that control root formation. and the subsequent growth and development processes, are very much alike, re gardless of the sites and sources of origin of the roots. Therefore, we included in the Sec ond Symposium contributions on both shoot-borne (i.e., adventitious) roots and root-borne (i.e., lateral) roots. Plant roots have remained an exciting and an intriguing field of sciencc. During thc years that followed the first symposium, an exceptional proliferation of interest in root biology has developed, associated with the intensive research activity in this field and the contemporary developments in the understanding of root function and development. New methods have been applied, and old ideas and interprctations werc rccxamined. Alto gether, it became necessary to update our viewpoints and to expand them.

In the last four decades of the twentieth century the use of sweetpotato was diversified beyond their classification as subsistence, food security, and famine-relief crop. In developing countries they serve both as human food and for feeding livestock. In Western countries they appeal to health conscious consumers because of their nutritional aspects. The sweetpotato is very high in nutritive value, and merits wider use on this account alone. The book has 2 parts. A general one giving up-to-date information on the history, botany, cultivars, genetic engineering, propagation, diseases and pests, nutritional data and marketing; and a second part presenting data on sweetpotato growing practices in different areas of the world. The information should be useful to researchers, practitioners and crop administrators in different countries.

The third edition of a standard resource, this book offers a state-of-the-art, multi-disciplinary presentation of plant roots. It examines structure and development, assemblage of root systems, metabolism and growth, stressful environments, and interactions at the rhizosphere. Reflecting the explosion of advances and emerging technologies in the field, the book presents developments in the study of root origin, composition, formation, and behavior for the production of novel pharmaceutical and medicinal compounds, agrochemicals, dyes, flavors, and pesticides. It details breakthroughs in genetics, molecular biology, growth substance physiology, biotechnology, and biomechanics.

Since the first edition of our book "Tissue Culture in Fores try" in 1982 we have witnessed remarkable advances in cell and tissue culture technologies with woody perennials. In addition to forest biologists in government, industry, and universities, we now have molecular biologists, genetic engineers, and biochemists using cell and tissue cultures of woody species routinely. There fore, the time has come for an update of the earlier edition. In our present effort to cover new developments we have expanded to three volumes: 1. General principles and Biotechnology 2. Specific Principles and Methods: Growth and Development 3. Case Histories: Gymnosperms, Angiosperms and Palms The scientific barriers to progress in tree improvement are not so much lack of foreign gene expression in plants but our current inabili ty to regenerate plants in true-to-type fashion on a mas sive and economic scale. To achieve this in the form of an appro pr iate biotechnology, cell and tissue culture will increasing ly require a better understanding of basic principles in chemistry and physics that determine structural and functional relationships among molecules and macromolecules (proteins, RNA, DNA) within cells and tissues. These principles and their relationship with the culture medium and its physical environment, principles of clonal propagation, and genetic variation and ultrastructure are discussed in volume one.

This is a completely revised edition of the previously titled Solute Movement in the Soil-Root System. It describes in detail how plant nutrients and other solutes move in the soil in response to plant uptake, and it provides a basis for understanding processes in the root zone so that they can be modeled realistically in order to predict the effects of variations in natural conditions or our own practices.

Organogenesis entails the regulation of cell division, cell expansion, cell and tissue type differentiation, and patterning of the organ as a whole. It is essential to gain insight into how organs are initiated and how they develop. However, this very often is subject to technical difficulties as these processes take place embedded deep in tissues or are difficult to access or visualize. To achieve this, we need specialized techniques such as those concisely illustrated in Plant Organogenesis: Methods and Protocols. Chapters address topics such as how to study and image the structure of ovules and embryos of Arabidopsis thaliana, tools to establish cell lineages in order to visualize the contribution of each cell and cell division to the building of a mature organ, approaches to study the totipotency of several plant cells, techniques such as the use of fluorescence-activated cell sorting (FACS) to analyse transcriptomes and hormone levels in Arabidopsis, methods to investigate organogenesis in economically important crops, and computer-based approaches to bring everything together. Written in the successful Methods in Molecular BiologyTM series format, chapters include introductions to their respective topics, lists of the necessary materials and reagents, step-by-step, readily reproducible protocols, and notes on troubleshooting and avoiding known pitfalls. Authoritative and easily accessible, Plant Organogenesis: Methods and Protocols serves both professionals and novices with its well-honed methodologies in an effort to further our knowledge of this fascinating research field.

This book provides a comprehensive coverage of the advances in genetics and genomics research on rice. The chapters feature the latest developments in rice research and cover such topics as the tools and resources for the functional analysis of rice genes, the identification of useful genes for rice improvement, the present understanding of rice development and biological processes, and the application of this present understanding towards rice improvement. The volume also features a perspective on synthesis and prospects, laying the groundwork for future advances in rice genetics and genomics. Written by authorities in the field, Genetics and Genomics of Rice will serve as an invaluable reference for rice researchers for years to come.

Introduces readers to the chemical biology of plant biostimulants This book brings together different aspects of biostimulants, providing an overview of the variety of materials exploited as biostimulants, their biological activity, and agricultural applications. As different groups of biostimulants display different bioactivity and specificity, advances in biostimulant research is illustrated by different examples of biostimulants, such as humic substance, seaweed extracts, and substances with hormone-like activities. The book also reports on methods used to screen for new biostimulant compounds by exploring natural sources. Combining the expertise of internationally-renowned scientists and entrepreneurs in the area of biostimulants and biofertilisers, The Chemical Biology of Plant Biostimulants offers in-depth chapters that look at: agricultural functions and action mechanisms of plant biostimulants (PBs); plant biostimulants from seaweed; seaweed carbohydrates; and the possible role for electron shuttling capacity in elicitation of PB activity of humic substances on plant growth enhancement. The subject of auxins is covered next, followed closely by a chapter on plant biostimulants in vermicomposts. Other topics include: exploring natural resources for biostimulants; the impact of biostimulants on whole plant and cellular levels; the impact of PBs on molecular level; and the use of use of plant metabolites to mitigate stress effects in crops. Provides an insightful introduction to the subject of biostimulants Discusses biostimulant modes of actions Covers microbial biostimulatory activities and biostimulant application strategies Offers unique and varied perspectives on the subject by a team of international contributors Features summaries of publications on biostimulants and biostimulant activity The Chemical Biology of Plant Biostimulants will appeal to a wide range of readers, including scientists and agricultural practitioners looking for more knowledge about the development and application of biostimulants.