This volume contains selected papers presented at the First Balkan Botanical Congress. The articles refer to all groups of plants and to all scientific disciplines in plant sciences and cover several major themes of current interest to botanists: taxonomy, geobotany and evolution: flora, vegetation, geographical distribution, pollen morphology and deposition, biodiversity, conservation, phytosociology biochemistry, metabolism and bioenergetics: secondary metabolites, enzymes, membrane transport, virus infection ecology and ecophysiology: metal accumulation and tolerance, toxicity and pollution, bio-monitoring systems, dynamics of vegetation communities, leaf structure and ecological types, UV-B and ozone radiation, pesticides and herbicides, ecological evaluation, management and protection of ecosystems, adaptation, photosynthesis structure and its dynamics: organization and molecular characterization of biomembranes and different cell structures and organelles, ultrastructure, anatomy, biosynthesis and localization of different cell compounds genetics, plant breeding and biotechnology: gene transfer, genetic engineering, genetic sterility and diversity, biodiversity and conservation, in vitro regeneration, micropropagation, genotype-environment interaction growth, development and differentiation: differentiation of cell structures, reproductive biology, photoreceptors, crop simulation model, regulators and plant morphogenesis, plant growth patterns, somatic-embryogenesis and organogenesis.

The International Society of Root Research sponsored the Symposium "Root Demographics and Their Efficiencies in Sustainable Agriculture, GrassLands and Forest Ecosystems," July 14-18, 1996, at the Madren Conference Center, Clemson University, Clemson, South Carolina, USA. The conference was a continuation of a series of international symposiums on root research held every three to four years. Symposiums have also been held twice in Vienna, Austria, and once in Uppsala, Sweden, and Almaty, Kazahkstan prior to the meeting at Clemson University. The sponsoring society has made a particular effort in these symposia to include root scientists from the former Soviet Union because of the importance of exchanging information on a worldwide basis. This symposium continued and promoted that effort by providing travel grants to several scientists from that region; however, funds for that purpose were limited. Therefore, in compiling these proceedings, a number of papers from scientists from the former Soviet Union and former Warsaw Pack countries have been included even though the scientists were not actually present for the SymPOSIum.

Achievements today in plant biotechnology have already surpassed all previous expectations. Plant biotechnology, integrated with classical breeding, is now on the verge of creating the evergreen revolution' to solve the world's envisaged tripled demand for food, agricultural commodities and natural products. New biotechnologies are being continuously adapted to agricultural practices, opening new vistas for plant utilization. Plant biotechnology is changing the plant scene in three major areas: (1) growth and development control (vegetative, generative and propagation), (2) protecting plants against the ever-increasing threats of abiotic and biotic stress, (3) expanding the horizons by producing specialty foods, biochemicals and pharmaceuticals. The potential for improving plant and animal productivity and their proper use in agriculture relies largely on newly-developed DNA biotechnology and molecular markers. These techniques enable the selection of successful genotypes, better isolation and cloning of favorable traits, and the creating of transgenic organisms of importance to agriculture. These areas were extensively discussed at the 9th international congress of the International Association of Plant Tissue Culture and Biotechnology, Plant Biotechnology and In Vitro Biology in the 21st Century', which was held in Jerusalem in June 1998. The present book of proceedings contains the variety of scientific achievements and techniques that were presented: Basic and Applied Aspects of Growth, Development and Differentiation; Genetic Manipulations: Transformation and Gene Expression, Hybridization, Haploidization and Mutagenesis; Genetic Stability and Instability, Selection and Variability; Regulation of Primary and Secondary Metabolism; Model Systems: Cell Cycle, Transport and Signal Transduction; Biotechnology for Plant Protection: Abiotic and Biotic Stress; Biotechnology for Crop Improvement: Yield, Quality and Production of Valuable Substances; Novel Micropropagation Methods; New Markets and Commercial Applications; Intellectual Property Rights.

The Fifth International Symposium on Nitrogen Fixation with Non-legumes was held in Florence (Italy) on 10-14 September, 1990. Earlier Symposia of this series were held in Piracicaba (Brazil), Banf Alberta (Canada), Helsinki (Finland) and Rio De Janeiro (Brazil). The Symposium's main objectives were to bring together scientists working in many different fields of nitrogen fixation, to stimulate discussion on this important process and to have an appraisal of the most recent studies concerning nitrogen fixation with non-legumes. The Symposium was attended by 230 scientists from 32 different countries. This volume collects the contributions of 65 lectures and 87 posters, which are an up-to-date account of the state of knowledge on biological nitrogen fixation with non-legumes. The book provides a valuable reference source not only for specialists in nitrogen fixation, but also for researchers working on related aspects of agronomy, biochemistry, genetics, microbiology, molecular biology and plant physiology. It is with great pleasure that we aknowledge the contributions of the authors in assuring the prompt pubblication of this volume. We would also like to express our thanks to Kluwer Academic Publishers B.V. for the publication of these Proceedings. M. Polsinelli R. Materassi M. Vincenzini ORGANIZING COMMITTEE President M. Polsinelli M. Vincenzini Secretary F. Favilli Treasurer E. Galli E. Gallori L. Giovannetti R. Materassi M.P. Nuti M.R. Tredici SCIENTIFIC COMMITTEE M. Bazzicalupo Florence, Italy H. Bothe Cologne, West Germany R.H. Burris Madison, U.S.A.

The 1997 European Conference on Spectroscopy of Biological Molecules (ECSBM) is the seventh in a biennial series of conferences devoted to the applications of molecular spectroscopy to biological molecules and related systems. The interest of these conferences rests mainly on the relationship between the structure and physiological activity of biological molecules and related systems of which these molecular species form part. This volume ofECSBM contains articles prepared by the invited lecturers and those making poster presentations at the seventh ECSBM. The reader will find mainly applications of vibrational spectroscopy to protein structure and dynamics, biomembranes, molecular recognition, nucleic acids and other biomolecules and biological systems containing specific chromophors. Biomedical applications of vibrational spectroscopy are expanding rapidly. On the other hand, a significant number of the papers describe applications of other methods, such as NMR, circular dichroism, optical absorption and fluorescence, X-ray absorption and diffraction and other theoretical methods. One aim has been to achieve a well balanced, critically comparative review of recent progress in the field of biomolecular structure, bonding and dynamics based on applications of the above spectroscopic methods. A great part of the contributions included in this volume are devoted to biomedical and biotechnological applications and provide a broadly based account of recent applicationS in this field. The content of this book has been organized in sections corresponding mainly to the different types of biological molecules investigated. This book includes also another section related to theoretical methods where MO calculations of vibrational frequencies dominate clearly the topic.

Volumes I and 2 of this Plant Biotechnology series reviewed fundamental aspects of plant molecular biology and discussed production and analysis of the first generation of transgenic plants of potential use in agriculture and horticulture. These included plants resistant to insects, viruses and herbicides, which were produced by adding genes from other organisms. Realisation of the potential of plant breeding has led to a resurgence of interest in methods of altering the structure, composition and function of plant constituents, which represents an even greater challenge and offers scope for improving the quality of a wide range of agricultural products. This, in tum, has resulted in a re-evaluation of priorities and targets by industry. Volume 3 of this series considers the biochemical and gentic basis of the biosynthesis of plant products such as starch, lipids, carotenoids and cell walls, and evaluates the ways in which biosynthesis of these products can be modified for use in the food industries. Authors also cover the biosynthesis of rare secondary products and the function and application of proteins for plant protection and therapeutic use. The emphasis throughout is on the relationship between fundamen tal aspects of biosynthesis and structure-function relationships, and application of this knowledge to the redesigning and altering of plant products by molecular genetics."

Several fundamental advances were announced at the Seventh International Symposium on Molecular Plant--Microbe Interactions held in Edinburgh in 1994. These included the cloning and identification of plant resistance genes involved in recognition of pathogens; the description of genetically engineered plants with novel resistance to pathogens; characterization of the molecular basis of pathogenicity of fungal and bacterial plant pathogens; and the mechanisms of communication used during recognition between symbiotic rhizobia and their host legumes. Participants in the Symposium contributed a series of papers that represent the leading edge of research in this important area of plant and microbial science. These articles are brought together to form this book, which will be essential reading for research workers, advanced students and others interested in keeping abreast of this rapidly developing area.

Dr Samuel Johnson, that famous eighteenth century lexicographer, said of oats 'A grain which in England is generally given to horses but in Scotland supports the people'. And presumably it was a Scotsman who riposted 'But what people and what horses ' That exchange encapsulates much of the history and role of oats - a cereal, once important as human food in parts of northern Europe but latterly used mainly as animal feed, especially favoured for horses. Although no longer a major food anywhere, oats still have a special and favoured niche in the cuisine of people living in the cooler and wetter regions of some parts of northern Europe. However, there is currently a resurgence of interest in the crop, because there is now considerable scientific evidence to support the view of Scotsmen who never doubted its dietary value. This book - very much an international effort, carefully orchestrated by Robert Welch - traces the origin, history and scientific progress which forms a sound basis for any further crop improvement and for broadening the utilization and marketing of oat products. Should rational consider ations lead to an increase in the importance of this cereal, I, for one, would be glad since I believe the rural landscape is the poorer for the increased rarity of golden fields of rippling oats which I used to be involved in harvesting."

This is the second volume in the series Nutrients in Ecosystems. Sulphur as an essential plant nutrient has received little attention. This is explained by the facts that sulphur was obviously in sufficient supply from the atmosphere, from soil and as a by-product in mineral fertilizers. Increases in the yield potential and thus in the nutrient requirement of modern crops, however, as well as remarkable changes in SO2 emissions by private households, power stations and industry, associated with legislative measures to reduce air and water pollution, have altered the situation to a large extent. In particular the public concerns about forest decline and pollution-induced climatic changes have initiated extensive research programs on the physiological functions of sulphur in plants, on the occurrence and plant availability of sulphur in agricultural and forest soils and on the chemistry of sulphur compounds in the tropo- and stratosphere. This book cannot be an encylcopedia of sulphur in all the media mentioned nor in all ecozones of the globe. However, it aims to give an overview of our present knowledge with a special focus on the sulphur situation in agrosystems of industrialised Western Europe. The ecological trends for sulphur observed in this region during recent decades are likely to be mirrored wherever industrialisation and urbanisation take place and where an increasing standard of living demands clean air, good drinking water and nutritious food. Agricultural production systems, therefore, require well-founded information on the actual sulphur nutrition and potential sulphur-fertilizer requirement of crops and soils respectively. It is hoped that this book will provide this information and will encourage further research where open questions still exist.

Over the past decade, advances in molecular biology have provided the impetus for a resurgence of interest in plant metabolism. At a general level, the potential for modifying the quantity or quality of harvestable crop products through genetic manipulation has provided an agronomic rationale for seeking a greater understanding of primary plant metabolism and its regulation. Moreover, the now facile techniques for transformation of many plant species and the consequential capacity to manipulate the amounts of specific individual enzymes within specific cell types provides an exciting direct approach for studying metabolic problems. Such transgenic plants are also becoming invaluable tools in studies at the interface between metabolism and other sub-disciplines such as physiology and ecology. The interest generated in plant metabolism by these developments has also encouraged the re-introduction of more conventional biochemical techniques for metabolic analysis. Finally, in common with other areas of cell biology, the wealth of information that can be obtained at the nucleic acid level has provided the stimulus for identification and characterisation of metabolic processes in far greater detail than previously envisaged. The result of these advances it that researchers now have the confidence to address problems in plant metabolism at levels not previously attempted. This book presents the proceedings of an international conference held on 9-11 January 1997 at St Hugh's College, Oxford under the auspices of the Phytochemical Society of Europe.

In the Netherlands the Institute for Soil Fertility Research plays a major role in soil biological, soil physical and plant nutritional research on the availability of nitrogen to crops. Main subjects of research are nitrogen turnover in the crop-soil ecosystem through biological transformations, nitrogen transport through the soil and nitrogen losses by leaching, denitrification and volatilization, and nitrogen use efficiency of various crops and cropping systems. The current knowledge in the different fields of research is integrated in simulation models. Simulation models not only make it possible to summarize and structure knowledge, but also, after verification, to extra- late the knowledge to situations different from the situations that have actually been studied. Such research is also carried out in other European and non-European countries. To compare the various simulation models currently in use, a workshop was organized by the Institute for Soil Fertility Research on 5-6 June 1990 on the occasion of its centennial. The title of the workshop was 'Nitrogen turnover in the soil-crop:: cosystem: modelling of biological transformations, transport of nitrogen and nitrogen use efficiency'. The 40 Jarticipants, who came from Canada and various European countries, were requested to run their model with data Jrovided by the Institute prior to the workshop. Data from 18 cases were made available to the participants: three ocations, three treatments, and two seasons.

Tropical climates, which occur between 23 Degrees30'N and S latitude (Jacob 1988), encompass a wide variety of plant communities (Hartshorn 1983, 1988), many of which are diverse in their woody floras. Within this geographic region, temperature and the amount and seasonality of rainfall define habitat types (UNESCO 1978). The F AO has estimated that there 1 are about 19 million km of potentially forested area in the global tropics, of which 58% were estimated to still be in closed forest in the mid-1970s (Sommers 1976; UNESCO 1978). Of this potentially forested region, 42% is categorized as dry forest lifezone, 33% is tropical moist forest, and 25% is wet or rain forest (Lugo 1988). The species diversity of these tropical habitats is very high. Raven (1976, in Mooney 1988) estimated that 65% of the 250,000 or more plant species of the earth are found in tropical regions. Of this floristic assemblage, a large fraction are woody species. In the well-collected tropical moist forest of Barro Colorado Island, Panama, 39. 7% (481 of 1212 species) of the native phanerogams are woody, arborescent species (Croat 1978). Another 21. 9% are woody vines and lianas. Southeast Asian Dipterocarp forests may contain 120-200 species of trees per hectare (Whitmore 1984), and recent surveys in upper Amazonia re corded from 89 to 283 woody species ~ 10 cm dbh per hectare (Gentry 1988). Tropical communities thus represent a global woody flora of significant scope.

All biomass is derived from photosynthesis. This provides us with food fuel, as well as fibre. This process involves conversion of solar energy, via photochemical reactions, into chemical energy. In plants and cyanobacteria, carbon dioxide and water are converted into carbohydrates and oxygen. It is the best studied research area of plant biology. We expect that this area will assume much greater importance in the future in view of the depleting resources ofthe Earth's fuel supply. Furthermore, we believe that the next large increase in plant productivity will come from applications of the newer findings about photosynthetic process, especially through manipulation by genetic engineering. The current book covers an integrated range of subjects within the general field of photosynthesis. It is authored by international scientists from several countries (Australia, Canada, France, India, Israel, Japan, Netherlands, Russia, Spain, UK and USA). It begins with a discussion of the genetic potential and the expression of the chloroplast genome that is responsible for several key proteins involved in the electron transport processes leading to O evolution, proton release and the production of 2 NADPH and A TP, needed for CO fixation. The section on photosystems discusses 2 how photosystem I functions to produce NADPH and how photosystem II oxidizes water and releases protons through an "oxygen clock" and how intermediates between the two photosystems are produced involving a "two electron gate".

JACQUES S. BECKMANN & THOMAS C. OSBORN Extraordinary progress has been made in the analyses of the genetic structures of higher eukaryotic genomes. Only ten years elapsed between the initial proposals to use molecular DNA markers for the generation of a complete linkage map of the human genome [5, 17] and the first description of a 10 centimorgan map of one of its chromosomes [22], soon to be followed by others. The availability of molecular DNA markers, henceforth called genomic markers [for a review of their properties see 1, 2, 20], represents a milestone in genetics by providing the capacity for complete genetic coverage of all genomes. It is important to remember that the nature of the DNA polymorphism or of the specific method used to uncover it can be quite different for different marker loci. The genetic variation detected can be a result of a simple point mutation, a DNA insertion/deletion event, or a change in repeat copy number at some hypervariable DNA [11] or micro satellite [21] motif. Currently, the methods of detection can involve use of restriction endonucleases, nucleic acid hybridization, or DNA sequence amplification. Each of these sources of var iation and methods of detection can have utility for different applications. Furthermore, new approaches for the detection of DNA polymorphism are constantly emerging. The primary concern here is that the monitored poly morphism defines a genetic marker 'useful' for the desired application.

Significant developments in recent years have led to a deeper understanding of the role and function of carotenoids in photosynthesis. For the first time the biological, biochemical, and chemical aspects of the role of these pigments in photosynthesis are brought together in one comprehensive reference volume. Chapters focus on the photochemistry of carotenoids in light harvesting and photoprotection, the nature and distribution of carotenoids in photosynthetic organisms, their biosynthesis, the herbicidal inhibition of carotenogenesis and the xanthophyll cycle'. Throughout details are given of the various methodologies used. A detailed appendix provides physical data for the major compounds. Carotenoids in Photosynthesis is an invaluable reference source for all plant scientists.

Considerable advances have been made in our understanding of the eukaryotic cell cycle at the molecular level over the past two decades or so, particularly in yeast and in animal systems. However, only in the past three or four years has progress been made in plants at the molecular level. The present volume brings together molecular biologists, cell biologists and physiologists to discuss this recent progress and how it relates to our understanding of the regulation of plant growth and development. The opening paper summarises the progress which has been made with fission yeast. Subsequent papers explore what is known about cell cycle control at the molecular level in plants, and about cell cycle regulation in specific physiological systems, ending with summary papers on cell division in roots and shoots. The book comprises up-to-date findings on a fundamental aspect of plant growth and development, and as such will be of particular interest to advanced undergraduates, postgraduates and research scientists in the fields of molecular biology, cell biology and physiology.

Research on the mechanisms of plant defense responses to stress and pathogen attack has attracted much attention in recent years. This increasing interest stems from the fact that the tools of molecular biology now enable us to study the molecular basis of old biological concepts such as host-pathogen recognition (and particularly the gene for-gene relationship), hypersensitive cell death and systemic acquired resistance. Our knowledge about avirulence and resistance genes, elicitors, signal transduction and genes involved in plant defense is rapidly expanding. Moreover we are just beginning to test in planta the potential of these results for biotechnological applications, aimed at improving plant resistance to diseases. The 2nd Conference of the European Foundation for Plant Pathology, hosted by the "Societe Fran~aise de Phytopathologie", was devoted to "Mechanisms of plant defense responses" and was held in Strasbourg, France. It brought together over 350 scientists from universities, research institutes and private sectors of 24 countries. Major advances in the areas under study have been reviewed in plenary lectures and are developed in the main articles of this book. Over 160 high-quality posters were presented and are summarized in short articles. Data from outstanding posters, which were discussed after a short oral presentation, are found in extended articles. As a whole the book presents a collection of papers arranged in six sections and reflecting the present day state-of-the-art of research in the field of plant defense reactions.

Photobiology - the science of light and life - begins with basic principles and the physics of light and continues with general photobiological research methods, such as generation of light, measurement of light, and action spectroscopy. In an interdisciplinary way, it then treats how organisms tune their pigments and structures to the wavelength components of light, and how light is registered by organisms. Then follow various examples of photobiological phenomena: the design of the compound eye in relation to the properties of light, phototoxicity, photobiology of the human skin and of vitamin D, photomorphogenesis, photoperiodism, the setting of the biological clock by light, and bioluminescence. A final chapter is devoted to teaching experiments and demonstrations in photobiology.
This book encompasses topics from a diverse array of traditional disciplines: physics, biochemistry, medicine, zoology, botany, microbiology, etc., and makes different aspects of photobiology accessible to experts in all these areas as well as to the novice. It is intended primarily for graduate students and for researchers who wish to look outside their speciality, but can also act as a source of information for undergraduate students.

The economic significance of boron (B) in agriculture, horticulture, and forestry has been beyond dispute for several decades. Even in the last two decades, the areas where B deficiency limits plant production has grown with increased reports from China, south Asia and southeast Asia. The present volume is reflective of the growing awareness of the significance of low soil B with reports from Australia, Bangladesh, Brazil, north, central and southern China, India, Nepal, and the North West Frontier Province of Pakistan contained herein. Boron deficiency also continues to be a problem for crop yield and quality in areas where B deficiency has been known for some time, for example in Germany and the USA. The problem of low soil B is not limited to effects on field crop yield, with papers reporting on depressed wood yield and quality in timber trees (Lambert et al. ), and depressed fruit quality (Dong et al. ; Smith et al. : Zude et al. ) also appearing in the present volume. Globally, Shorrocks (1997)1 estimates that ?? tonnes of B fertiliser is applied annually in agriculture. The economic benefits from the use of B fertiliser have not been quantified but are clearly enormous. Paradoxically, the clear economic imperatives for using B fertiliser on low B soils are not matched by a similar clarity of understanding of the role and functions of B in plants.

In this study, an overview is presented of agricultural policies on manure and minerals, relating to the Nitrate Directive to remedy excessive surface- and groundwater contamination from intensive agricultural practices. Six countries belonging to the European Union were studied: the Netherlands, Belgium, Denmark, France, Germany and the United Kingdom. The policies and their legal incorporation were related to agricultural and environmental conditions in each country. In addition, an inventory was made of agricultural mineral poli cies in the United States and Canada. Conditions for livestock farming in North America differ considerably from those in Europe, but their solutions shed a different light on European policies. Research has shown that there are still very considerable mineral surpluses in many countries and regions. In both the Netherlands and in the Flemish part of Belgium, existing problems due to very high levels of manure production are structural rather than local and cannot easily be solved by transport of manure to other regions. To a lesser extent. Germany, Denmark and relatively small parts of France (Brittany) and the United Kingdom, still exceed the norms for an equilibrium fertilization. In Denmark, existing problems can probably be solved within the existing legislative framework. The Netherlands, Flanders. several German Lander (Nordrhein-Westfalen and Schleswig-Holstein) and Brittany.

Proceedings of the International Workshop on Gelidium held in Santander, Spain, September 3-8, 1991

Plant Production on the Threshold of a New Century describes and compares problems and frontier developments in the different sectors of plant production, integrating developments in basic plant sciences, crop science and socioeconomic science, leading to sustainable plant production. Hence the book formulates goals and constraints in policy, economy, production, environment and land use; indicates how these goals and constraints may be translated into farming styles and cropping systems; and describes how the fundamental plant sciences can contribute to the implementation of such farming styles and cropping systems.

The study of plant mineral nutrition has both academic and applied aspects to it. Today, research into plant mineral nutrition is more pertinent than ever in the face of a growing world population and the increasing need for sustainable agriculture. In Plant Mineral Nutrients: Methods and Protocols, expert researchers in the field detail a comprehensive collection of methodologies that are routinely used in plant mineral nutrition research. These include methods and protocols for plant growth parameters, ion contents and composition, soil analyses, flux measurements and the use of public facilities for high throughput analyses. Written in the highly successful Methods in Molecular Biology (TM) series format, chapters include introductions to their respective topics, lists of the necessary materials and reagents, step-by-step, readily reproducible laboratory protocols, and key tips on troubleshooting and avoiding known pitfalls. Authoritative and practical, Plant Mineral Nutrients: Methods and Protocols seeks to aid scientist in the further study of into plants and their mineral nutrients.

Many organisms have evolved the ability to enter into and revive from a dormant state. They can survive for long periods in this state (often even months to years), yet can become responsive again within minutes or hours. This is often, but not necessarily, associated with desiccation. Preserving one's body and reviving it in future generations is a dream of mankind. To date, however, we have failed to learn how cells, tissues or entire organisms can be made dormant or be effectively revived at ambient temperatures. In this book studies on organisms, ranging from aquatic cyanobacteria that produce akinetes to hibernating mammals, are presented, and reveal common but also divergent physiological and molecular pathways for surviving in a dormant form or for tolerating harsh environments. Attempting to learn the functions associated with dormancy and how they are regulated is one of the great future challenges. Its relevance to the preservation of cells and tissues is one of the key concerns of this book.

The study of plant development using molecular and genetic techniques is rapidly becoming one of the most active areas of research on flowering plants. Developmental Biology of Flowering Plants relates classical developmental work with the outstanding problems of the future in the study of plant development. An important feature of this book is the integration of results from molecular and genetic studies on various aspects of plant development in a cellular and physiological context.