This book is a collection of papers presented at a NATO Advanced Research Workshop on "Biology and Molecular Biology of Plant-Pathogen Interactions" which was held at Dillington College, Ilminster, UK, 1-6 September 1985. It had been preceded by Advanced Study Institutes at Porte Conte, Sardinia in 1975 and at Cape Sounion, Greece in 1981. In recent years, methods for the manipulation and transfer of genes have revolutionized our understanding of gene structure and function. It was thus opportune to bring together scientists from distinct disciplines, e. g. plant pathology, cytology, biochemistry and molecular biology to discuss our present understanding of cellular interactions between plants. We also explored how the potential offered by the newer molecular technologies could best be realized. It soon became evident at the Workshop, and is a repeated theme of this publication, that future research will need concentrated multi disciplinary programmes. Many of the new approaches will be valuable. For example, immunocytochemistry does, for the first time, allow molecules to be located precisely within infected tissues. Equally, the methods of DNA isolation and gene transformation will facilitate the isolation and characterization of genes associated with pathogenesis and specificity. The description at the Workshop of immunocytochemical protocols and of transformation systems for pathogenic fungi have already stimulated an upsurge in research on plant-pathogen relationships. The papers discuss many interactions between plants and fungal and bacterial pathogens, but also provide a comparison with mycorrhizal and symbiotic relationships, and those involving mycoparasites."

The XXX Congress of the International Union of Physiological Sciences took place in Vancouver, Canada, in July 1986; and this Volume contains a selection of the Review Lectures which formed part of the Congress programme. They cover most of the areas of contemporary physiology and were presented by distinguished scientists from many parts of the world. An innovation at this Congress was the inclusion in the programme of a number of lectures devoted to historical subjects. These lectures attracted large audiences at the meetings, and three of them also appear in this book. Finally, the Plenary Lectures which formed part of the opening and closing ceremonies and which deal with some aspects of Canadian physiological history, find a place here as well. The Editors are grateful to all of the authors who provided the manuscripts which go to make up this book, and to John Donald for his invaluable assistance in the preparation of the final text; as well of course to all of the contributors whose participation made the Congress the success which it was. It is hoped that this Volume will provide a useful memento of the event.

The oil crisis during the 1970s turned interest towards the utilization of renewable resources and towards lignocellulosics in particular. The 1970s were also the cradle period of biotechnology, and the years when biotechnical utilization of lignocellulosic waste from agriculture and forestry gained priori ty. This was a logical conclusion since one of nature's most important biologi cal reactions is the conversion of wood and other lignocellulosic materials to carbon dioxide, water and humic substances. However, while biotechnology in other areas like medicine and pharmacology concerned production of expen sive products on a small scale, biotechnical utilization and conversion of ligno cellulosics meant production of inexpensive products on a large scale. Biotechnical utilization of lignocellulosic materials is therefore a very difficult task, and the commercial utilization of this technology has not progressed as rapidly as one would have desired. One reason for this was the lack of basic knowledge of enzyme mechanisms involved in the degradation and conversion of wood, other lignocellulosics and their individual components. There are also risks associated with initiating a technical development before a stable platform of knowledge is available. Several of the projects started with en thusiasm have therefore suffered some loss of interest. Also contributing to this failing interest is the fact that the oil crisis at the time was not a real one. At present, nobody predicts a rapid exhaustion of the oil resources and fuel production from lignocellulosics is no longer a high priority."

After the 1988 and 1989 volumes, this is the third volume on Medicinal and Aromatic Plants. Each of the 29 chapters contributed by international scientists deals with one individual plant genus, namely "Atropa," "Ageratina," "Ailanthus," "Aconitum," "Apium," "Aloe," "Akebia," "Bidens," "Carthamus," "Chamomilla," "Carum," "Citrus," "Cymbopogon," "Dysosma," "Euphorbia," "Fritillaria," "Glycyrrhiza," "Lavandula," "Nigella," "Pelargonium," "Perilla," "Podophyllum," "Rosa," "Scutellaria," "Securinega," "Solanum," "Swertia," "Symphytum," "Syringa." Their distribution, economic importance, conventional propagation, in-vitro propagation and production of metabolites through tissue culture are treated in detail. Special emphasis is laid on the potential of industrial in-vitro production of plant compounds of medical and pharmaceutical relevance using tissue culture.

Among basic human needs, food is foremost. Finding sufficient, affordable food is still the major concern of one in every five persons on earth. Rice is the basic staple for more than half of the world - and will continue to be well into the future. For this reason, the Interna tional Rice Research Institute (IRRI) has set the goal of improving the well-being of present and future generations of rice farmers and consumers, particularly those with low incomes. As we look toward the 21st century, several important issues cloud food security. World population is growing by almost 100 million people per year, and it is not likely to plateau before the end of the next century. This means that food demand will at least double, and may quadruple. The technologies of the Green Revolution have provided an unprecedented leap in annual rice production, enough to feed 600 million more people, but have had unforeseen social and environmental costs. Loss of genetic diversity and misuse of pesti cides endanger the sustainability of the Green Revolution. Soil ero sion, rural to urban popUlation migration, and increased competition for land and water between urban and agricultural sectors further threaten the sustainability of rice production. Finally, human activi ties may be changing the global climate. Any change in global climate is a potential challenge to the food security offuture generations. The world cannot afford to be unprepared."

Interest in trees, whether in our streets, parks or forests, has in- creasedconsiderablyin thelast 20 years or so.One reason for this has been the decline and dying of forests, which caused great concern about our environment during the 1980s. Because ofthe prominenceofthis event,which is nowblamedon abiotic factors, it is all too easyto forget that the life oftrees is also affected by a multitude of biotic factors: viruses, bacteria, fungi and animals. These may have very different relationships with trees, but are usually deleterious. The fungi playa particularlyimportant part, and during the course of their evolution they have developed various abilities and strategies in order to obtain nutrients and energy by decomposing wood. On the other hand, the tree has 'learned' to react to external and internal infections. The various interactions between fungi and trees form the main themeofthis book. In reviewing this new book I was involuntarily reminded of a work by Robert Hartig over a century ago, entitled Die Zerset- zungserscheinungen des Holzes der Nadelbiiume und der Eiche in forstlicher, botanischer und chemischer Richtung, which laid the foundation of mycological and pathological research on wood.

Interdependence between species is a law of nature. The degree of this interdependence is vividly evident in the plant-microbial world. Indeed, there is no axenic plant in nature and one finds various forms of interac tions between these two kingdoms ranging from completely innocuous to obligate parasitic. Most of these interactions are poorly understood at the molecular and physiological levels. Only those few cases for which a molecular picture is emerging are discussed in this volume. With the advent of recombinant DNA technology and the realization that some of these interactions are very beneficial to the host plant, a spate of activity to understand and manipulate these processes is occurring. Microbes interact with plants for nutrition. In spite of the large number of plant-microbe interactions, those microbes that cause harm to the plants (i. e., cause disease) are very few. It is thus obvious that plants have evolved various defense mechanisms to deal with the microbial world. The mecha nisms for protection are highly diverse and poorly understood. Some pathogens have developed very sophisticated mechanisms to parasitize plants, an excellent example for this being crown gall caused by a soil bac terium, Agrobacterium tumefaciens. A remarkable ingenuity is exhibited by this bacterium to manipulate its host to provide nitrogenous compounds which only this bacterium can catabolize. This is carried out by a direct gene transfer mechanism from bacteria to plants."

The publication of this volume of The Viruses entitled The Togaviridae and Flaviviridae comes at an appropriate time. The structure and rep lication strategies of these viruses are now known to be sufficiently di verse to warrant the removal of flaviviruses from the Togaviridae family and establish them as an independent family. Flaviviridae have a special place in the history of virology. The prototype virus-yellow fever virus was the first virus to be identified as the cause of a human disease. Some of the history of this discovery is described in Chapter 1 of this volume; in Chapter 10 the complete sequence of the RNA genome of the virus is presented. This sequence not only defines the primary structure of the viral proteins, it also clarifies the mechanism of translation of the fla vivirus genome. Knowledge of the sequence of the structural proteins of these viruses represents an important step in the potential goal of using purified flavivirus glycoproteins as vaccines. Many of the chapters in this volume focus on the structure and replication of the Togaviridae. These viruses have provided valuable models for studies in cell biology, partic ularly with regard to the cotranslational and posttranslational steps re quired for the synthesis and localization of membrane glycoproteins. Fur thermore, Togaviridae have been pivotal in our growing understanding of how enveloped viruses enter and exit from cells. The broad outlines of the structure and gene expression of Togavir idae and Flaviviridae are known, but important questions remain."

This book is the first comprehensive description of development of the Acipenserid fish published in the English language. It con tains the results of more than 40 years of studies by the authors and their colleagues. My own life in science has been intimately related both with the authors and the fish, which are the subject of this book. Therefore, it gives me a great pleasure to present to the English reader an expanded version of the book. Those interested in the history of biology must be well aware of the fact that genetics in the USSR was practically demolished by Lysenko at the session of the Lenin All-Union Academy of Agricultural Sciences in 1948. However, it is much less well known that other fundamental branches of biology were also persecuted at that time, experimental embryology (developmental mechanics) among them. As a result, many embryologists, in cluding the authors of this book, were forced to turn to more ap plied problems, this being the only way to continue research. They had to abandon amphibians and concentrate their efforts on sturgeon."

The floricultural industry has been undergoing an unprecedented revolu tion in terms of the type of commodity produced and the production and marketing technology in both developed and developing countries. As a result of this revolution, as we know today, there is a flower for every purpose and for every person in the world, as is evident from the slogan of the Society for American Florists: "say it with flowers." In re cent years, the Latin American and European countries have become sizeable competitors for the North American fresh flower markets and the trend continues growing. Like any other crop production, floricultural production can be divided into three basic factors: (1) production costs (2) quality (3) transportation costs. All these must be optimum for this area or industry to be safe from competition. With increasing consumer awareness and the current recession, the pressure from the artificial floral products in dustry and also of neighbouring countries on the American fresh flower industry, and continued competition even amongst the growers, whole salers and retailers, quality in floricultural industry is becoming increas ingly important to all those concerned with handling these products. The visual quality aspects of the product are the sole determiner of consumer acceptability in this industry and, unlike fruits and vegetables, flowers cannot be marketed by just discarding the damaged portion."

Agricultural, natural resource, and environmental problems are becom ing increasingly interdependent. For example, soil erosion is largely determined by agricultural land use. Both water use and water con tamination depend on land use and technology choice in agriculture. In many areas, the fertilizers and pesticides used in agriculture are ma jor pollutants of ground and surface water, having adverse effects on drinking water and fisheries. Agricultural pollutants such as pesticides also produce adverse health effects for agricultural workers and the consuming public. On the other hand, the availability of water resources and the value of competing land uses influence agricultural production. Additionally, regional air quality problems may affect crops and global environmental trends may have long-term implica tions for farming. Agriculture, natural resources and environmental quality are all heavily regulated in the U. S., but they are done so by a vast array of competing or unrelated agencies within the U. S. Departments of Agriculture, Interior, and Commerce, the Environmental Protection Agency; and numerous state agencies. Considering the large number of bureaucratically remote public agencies involved and the pervasive in terdependencies between agriculture, natural resources and the environ ment, policies develop which are at best uncoordinated and at worst conflicting and counterproductive. These policies have become sources of controversy as different interest groups struggle to affect their im plementation, as different agencies have fought for administrative con trol and as legislative bodies have attempted to enact piecemeal changes."

Genetic engineering through DNA recombinants and the in vitro manipulation of isolated protoplasts has recently attracted much atten- tion in agricultural biotechnology, and has greatly advanced during the last 5 years. In an earlier book, Plant Protoplasts and Genetic Engineer- ing I, methods for the isolation, fusion and culture of protoplasts were reviewed and the regeneration of complete plants from isolated pro- toplasts of rice, potato, soybean, linseed, cabbage, chicory, lettuce, but- terbur, orchids, citrus and some other tree species, and interspecific and intergeneric somatic hybrids in Lycopersicon, Petunia, Nicotiana, Solanum, Glycine, Citrus, Brassica, Medicago and Trifolium spp. were discussed. The present volume, Plant Protoplasts and Genetic Engineering II, deals with some of the newer techniques such as microinjections, elec- trofusion, flow cytometry, uptake and integration of DNA, nuclei, iso- lated chromosomes by plant protoplasts and the subsequent regeneration of transgenic plants. The literature on the DNA recombinants and genetic transformation, both Agrobacterium-mediated and direct gene transfer in agricultural crops and trees, such as poplars, is reviewed, and the uses of cytoplasts and miniprotoplasts in genetic manipulation are highlighted.

An introductory discussion of basic chromosome structure and function preceeds the main text on the application of cytogenetic approaches to the analysis of the manipulation of both the genetic make-up and the genetic transmission system of plant breeding material. Analysis using light and electron microscopy, segregations and molecular techniques, yields information for assessing the material before and after manipulation. Much attention is given to quantitative methods. Manipulation not only involves the construction of specific genotypes, but also chromosomal transmission systems. Although analysis and manipulation in the somatic cycle are considered, the focus is on the generative cycle, with emphasis on analysis and subsequent segregation of specifically constructed material. The book is intended for plant breeders and other scientists interested in the analysis and manipulation of breeding material at the chromosomal level. Comparisons with molecular and cell biological approaches are made, and the potential of the various methods is evaluated.

The aim of this book is to provide an accessible overview for advanced students, resource professionals such as land managers, and policy makers to acquaint themselves with the established science, management practices and policies that facilitate sequestration and allow for the storage of carbon in forests. The book has value to the reader to better understand: a) carbon science and management of forests and wood products; b) the underlying social mechanisms of deforestation; and c) the policy options in order to formulate a cohesive strategy for implementing forest carbon projects and ultimately reducing emissions from forest land use.

H. BINDING and J. REINERT In collaboration with the first authors of this volume This volume is devoted to the development of cell clones and plants from ma nipulated cells: isolated protoplasts, cell fusion bodies, and transformed cells. Isolated protoplasts represent cells which are liberated from their walls and separated from the differentiation pattern of the organism. Investigations on re generation from protoplasts provide a better understanding of the process and control of developmental pathways. Whereas protoplast isolation results in alteration of the state of differentiation of a cell, protoplast fusion is a means for the creation of cells with novel genetic constitution. Fascinating features are (1) to hybridize cells which-unlike gametes -did not derive from meiosis products, (2) to bring together foreign plastids and mitochondria and to investigate their parasexual reactions, and (3) to match ge netic traits which had been separated for long periods of evolution. Highly sophisticated techniques have already been elaborated for the transfer of genes by the use of isolated DNA and gene transfer systems. Highly promising results have already been obtained by the use of Ti plasmids of Agrobacterium, but direct DNA transformation is also proving to be useful. Most of the results in these areas are preliminary and/or limited to a few sys tem.lt is the aim of this volume to present the main features, but at the same time to draw attention to problems and perspectives of protoplast regeneration and so matic cell genetics in order to stimulate further investigations."

T. C. Hutchinson The NATO Advanced Research Workshop detailed in this volume was held in Toronto, Canada, in 1985. The purpose of the Workshop was to provide a "state of the art" report on our knowledge of the sensitivities and responses of forests, wetlands and crops to airborne pollutants. Approximately 40 scientific experts from nine countries participated. Most participants were actively involved in research concerning the effects of air pollutants on natural or agro-ecosystems. These pollutants included acidic deposition, heavy metal particulates, sulphur dioxide, ozone, nitrogen oxides, acid fogs and mixtures of these. Also invited were experts on various types of ecosystem stresses, physiologi cal mechanisms pertinent to acid deposition, and other areas that were felt by the director to be of direct relevance, including: effects of ethylene on vegetation, the physiology of drought in trees, the nature and role of plant cuticles as barriers to acid rain penetration, the use of dendrochronological techniques in reconstructing the time of onset and the subsequent progression of growth declines, the ability of soils to naturally generate acidity, the role of Sphagnum moss in natural peat land acidity, the use of lichens as indicators of changing air quality, and the magnitude of natural emissions of reduced sulphur gases from tropical rainforests and temperate deciduous forests. The Workshop included a series of invited presentations and subsequent group discussions. These presentations were designed to allow syntheses of our present knowledge as well as detailed questioning and discussion."

A number of interdisciplinary fields related to "Plant Cell " "Biotechnology" are discussed. The two main directions are: Plant cell culture in agricultural applications for the improvement of crops and industrial applications in the production of secondary metabolites. A number of areas such as physiological and biochemical aspects of autotrophic cells, gene characterization in higher plants, transformation of plant cells, genetic stability in plant cell cultures, somatic hybridization and somatic embryogenesis are treated. Recent knowledge on somaclonal and gametoclonal variation as well as on the obtainment of protoplasts and their use for the isolation and culture of heterocaryons as tools for plant breeding are considered. Furthermore, the knowledge on biomass production in fermentor conditions and the role of immobilization for increased production and scale-up of plant cells are discussed.

This book provides a quantitative analysis of the role of woody plants in semi-arid regions, for the aSSessment of their benefits in agrosylvopastoralland-use systems with productive and sus tainability objectives. The insights presented and conclusions drawn allow the additional benefits of woody plants for specific climatic and physical site conditions and land-use systems to be estimated. The Sahel and Sudan zones in West Africa, on which the book focusses, represent resource-poor conditions, whose ecological dynamics have been relatively well studied. The role of woody plants in this region, as assessed in this book, is extrapolated to other semi-arid regions, leading to general conclusions on agroforestry's potential as an option for sustainable land use in semi-arid regions. The origins of this book go back to 1982, when the Club du Sahel requested that available data on woody plants in the Sahel region be synthesised, to provide basic information to enable better attention to be given to woody plants in rural development programmes. We are grateful to the Club du Sahel for this challenge. Various people contributed to studies used in this book. The preliminary inventory of the data available was made by Frits Ohler; later his work was continued by Franciska Dekker."

Can a continuous growth of agriculture be achieved in the sub-Sahara region without inducing irreversible damage to the ecosystem? Until now, doubts have been expressed as to the actual capacity of the soils to sustain a desirable increase of production which can match the requirements of a fast-growing population. Thirty years of investigation and a renewed comprehensive interpretation of research data on soil fertility show that a sustainable agriculture growth could be a practical possibility in a savannah region.

Wild taxa are invaluable sources of resistance to diseases, insects/ pests, nematodes, temperature extremes, salinity and alkalinity stresses, and also of nutritional quality; adaptation; genetic diversity and new species. Utilization of wild relatives of a crop depends largely upon its crossability relations with cultivated varieties. Sev eral wild species are not crossable with the commercial cultivars due to various isolation barriers. Furthermore, in a few cases, hybridiza tion is possible only in one direction and reciprocal crosses are not successful, thus depriving the utilization of desired cytoplasm of many species. However, techniques have been developed to over come many barriers and hybrid plants are produced. New crop species have been developed by overcoming the F 1 sterility and producing amphidiploids and such crops are commercially being grown in the field. The segregation pattern ofF 1 hybrids produced by distant hybridization in segregating generations are different from the intervarietal hybrids. In former cases, generally, unidirectional segregation takes place in early generations and accordingly, selec tion procedures are adopted. In most of the cases, backcross or modified backcross methods have been followed to utilize wild species, and thus numerous types of resistance and other economical attributes have been transferred in the recurrent parents. Protoplast fusion has been amply demonstrated in a number of cases where sexual hybridization was not possible and, as a result, hybrids have been produced."

Haploid plants have the gametophytic number of chromosomes. They are of great importance, especially in studies on the induction of muta tions and also for the production of homozygous plants, they are needed in large numbers. The conventional methods employed by plant breeders for their production are cumbersome, time-consuming, laborious and rather inefficient. Sometimes it may take years to produce a pure line. However, with the introduction of in vitro techniques, especially anther culture for the induction of androgenesis, it has become increasingly evi dent that these methods considerably accelerate the production of haploids for plant breeding programs. During the last decade, in vitro-produced haploids have been incor porated into breeding programs of many agricultural crops, and positive results have been obtained especially with rice, wheat, potato, barley, maize, asparagus, sunflower, brassica, tobacco, etc. Among these, rice and wheat are the best examples in which a number of improved varieties have been released. In wheat, the breeding cycle can be shortened by three or four generations when the pollen haploid breeding method is used instead of conventional cross-breeding. The release of the wheat varieties Jinghua 1 and Florin is a typical example of what can be achieved with other crops. Taking these developments into considera tion, the present volume, Haploids in Crop Improvement I, was compil ed.

This volume is dedicated to understanding the political economy obstacles to trade reform, especially global agricultural trade reform, and how these obstacles can be surmounted. The focus is on the trade reform under the GATT negotiations. New political-economic methodologies are used to assess and evaluate the obstacles and original scholarly analyses have been designed to explain why agriculture - among so many topics - became such a significant problem in the most recent Uruguay Round of the GATT.

Most forest tree species were considered recalcitrant a decade ago, but now with the improved in vitro techniques some progress has been made towards culture-of tree species. Micro propagation has been achieved from the juvenile tissues of a number of forest tree species. On the other hand, tissues from most mature trees are still very difficult to grow and differen tiate in vitro. Nevertheless, there has been slow but steady progress in the application of tissue culture technology for culture of tissues, organs, cells and protoplasts of tree species. As compared to most agricultural crops, and herbaceous plant species, trees are a different lot. They have long gene ration cycles. They are highly heterozygous and have a large reservoir of genetic variability. Because of this genetic variability, their response in vitro is also variable. On a single medium, the response of tissues from different trees (genotypes) of a single species may be quite different: some responding by induction of growth and differentiation, while others showing minimal or no growth at all. That makes the somatic cell genetics of woody plants somewhat difficult, but at the same time interesting."

Modern Methods of Plant Analysis When the handbook Modern Methods of Plant Analysis, was first introduced in 1954, the considerations were: 1. the dependence of scientific progress in biology on the improvement of existing and the introduction of new methods; - 2. the difficulty in finding many new analytical methods in specialized journals which are normally not accessible to experimental plant biologists; 3. the fact that in the methods sections of papers the description of methods is frequently so compact, or even sometimes to incomplete, that it is difficult to reproduce experiments. These considerations still stand today. The series was highly successful, seven volumes appearing between 1956 and 1964. Since there is still today a demand for the old series, the publisher has decided to resume publication of Modern Methods of Plant Analysis. It is hoped that the New Series will be just as acceptable to those working in plant sciences and related fields as the early volumes undoubtedly were. It is difficult to single out the major reasons for the success of any publication, but we believe that the methods published in the first series were up-to-date at the time and presented in a way that made description, as applied to plant material, complete in itself with little need to consult other publications. Contribution authors have attempted to follow these guidelines in this New Series of volumes. Editorial The earlier series of Modern Methods of Plant Analysis was initiated by Michel v.

th th On June 17 and 18 1987 the fourth workshop on "Azospi rillum: Genetics, Physiology, Ecology" took place at the Uni ver sity of Bayreuth, West Germany, organized by the Genetics depart ment. There were about 80 participants, who came from German research institutions, from other European countries, from Is rael, Egypt, India, North Vietnam, and North and South America. The former workshops had also taken place in Bayreuth, in 1981, 1983 and 1985, hence the organizers could draw on the experience obtained at these earlier workshops. Azospirilla have, during the past 15 years, found an ever increasing scientific interest because, first, these soil bacte ria carry the genetic information for binding molecular nitrogen from the air and, second, they live in close vicinity to the roots of grain crops and forage grasses. By exploitation of these two properties, it is hoped to develop inoculation procedures which can be used in nitrogen-deficient soils.