Planternes biologi

It appears that a comprehensive and up-to-date book on the impact of virus diseases on the major crops in developing countries is now much needed, especially as there have been rapid advances in the biological and molecular characterization and detection of the pathogens and possible approaches for their control. On the other hand, the economic losses caused by many of these diseases are tremendous and much of the accumulated knowledge to diminish the crop losses has not filtered through, or cannot be applied. This book is focused on the important crops. Each chapter on a specific crop will include inter alia, geographical distribution, the viruses - symptoms, damage, detection - a brief description of the viruses concerned, and present and future ways for their control. Experts from India, Nigeria, UK, USA, France, Germany, Peru, Japan, Australia, Netherlands, Venezuela, Kazakhstan and Israel (many of them from the International Research Institutions) have contributed chapters to this book.

Tree species are indispensable to human needs. Due to their long life cycle and environmental sensitivity, breeding trees for sustainable production is a formidable challenge in order to meet the demands of growing human population and industries. Fruit crops such as apple, cocoa, mango, citrus, litchi, pear, dates, and coconut or industrial crops including rubber and tea, improving yield under the optimal, sub-optimal and marginal areas call for a unified worldwide effort. While the uniqueness of coconut as 'kalpavriksha' (Sanskrit - meaning tree of life) makes its presence in every continent from Far East to South America, tree crops such as cocoa, oil palm, rubber, apple, peach and walnut prove their environmental sensitivity towards tropical, subtropical and temperate climates. Date palm is quintessential for desert climate. Thus, from soft drinks to breweries to oil to tires, the value addition offers a spectrum of products to human kind, enriched with nutritional, environmental, financial, and trade related attributes. This volume is a compilation of information on breeding of temperate tree species and provides first hand comprehensive knowledge to research, teach, and make policies.

Allelopathy is a fascinating and perplexing topic that concerns the chemical interactions of plants. It has profound implications in agriculture and forestry where species are grown artificially in mixture, with no evolutionary history of co-existence. The topic of allelopathy is widely credited as commencing in 1937, when the term ¿allelopathy¿ was coined by Molisch. However, the concept of allelopathy has been recorded since Greek and Roman times, became extremely controversial in the first half of the 19th century, and remains so today. This book concerns a virtually unknown treatise by Justus Ludewig von Uslar, published in 1844, which emerges as the first book entirely devoted to the concept of allelopathy. The book provides the historical background to allelopathic knowledge, from antiquity to c. 1840. It also provides for the first time a biography of Justus Ludewig von Uslar, who is best known as the first Consul-General for Hannover in Mexico, and Director of the Mexican Company, a British venture mining company. In many ways von Uslar epitomises the tradition of the gentleman scientist of the 19th century. The book then offers a full translation into English of von Uslar's rare treatise, which foreshadows many ideas current in allelopathic research.

The Annual Beltsville Symposium provides a forum for interaction among scientists involved in research that has vital impact on agriculture and on the agricultural sciences. The 10th Symposium in the series, Biotechnology for Solving Agricultural Problems, focuses on the use of a revolutionary new set of tools, biotechnology, and attempts to define the set in terms of its applications in agriculture. Biotechnology has already contributed to the genetic improvement of agricultural products. Procedures that were impossible to test or to implement in the past because of technological limitations are now routinely used by many scientists. Four areas that have benefitted from advances in biotechnology are covered in the symposium proceedings. These areas include genetic manipulation, nutrition, health and disease, and natural resource management. The 31 invited speakers have identified programs of basic and applied research on plants, animals, and insects that fall within these broad areas. Their research strategies included such techniques as germline modification, gene mapping, monoclonal antibody production, and gene transposition. These strategies have tapped new well springs of information and technologies ranging from the regulation of gene expression (and with it, the regulation of development, growth, disease resistance, and nutrient metabolism) to degradation of pesticides and toxic wastes. The applications of biotechnology to agricultural research have opened virgin vistas with enormous potential. The new biotechnological techniques and those that will evolve with their use will contribute markedly to the capacity of the agricultural sciences to advance the well-being of the human race.

Life has evolved as a unified system; no organism exists similar role also has been suggested for fatty acids from alone, but each is in intimate contact with other organisms cyanolipids. Nonprotein amino acids, cyanogenic glyco- and its environment. Historically, it was easier for workers sides, and the non-fatty-acid portion of cyanolipids also are in various disciplines to delimit artificially their respective incorporated into primary metabolites during germination. areas of research, rather than attempt to understand the entire Secondary metabolites of these structural types are accumu- system of living organisms. This was a pragmatic and neces- lated in large quantities in the seeds of several plant groups sary way to develop an understanding for the various parts. where they probably fulfill an additional function as deter- We are now at a point, however, where we need to investi- rents to general predation. gate those things common to the parts and, specifically, those The second type of relationship involves interaction of things that unify the parts. The fundamental aspects of many plants with other organisms and with their environment. Bio- of these interactions are chemical in nature. Plants constitute logical interactions must be viewed in the light of evolution- an essential part of all life systems; phytochemistry provides ary change and the coadaptation, or perhaps coevolution, of a medium for linking several fields of study.

During the last decade, research on Pseudomonas syringae pathovars and related pathogens has progressed rapidly, opening up many new avenues. The application of molecular genetics has provided new insights into determinants of pathogenicity and virulence. Progress has also been made in elucidating the chemical structures and modes of action of phytotoxins from Pseudomonas syringae; by establishing novel strategies for disease control; in biotechnological applications; by studying the resistant reaction of the plant with a combined biochemical and genetic approach; and in the development of new detection and identification methodologies as tools in epidemiological studies. With such rapid advances it becomes more and more difficult to keep abreast of the developments and concepts within disciplines, all involving research on pathovars of P. syringae. In an attempt to provide a balanced overview, recent developments in these rapidly expanding fields have been critically reviewed at the beginning of each chapter by internationally renowned experts. Our comprehensive coverage has been made possible because all the contributors to this volume presented their latest findings at the `5th International Conference on Pseudomonas syringae Pathovars and Related Pathogens' in Berlin, September 3-8, 1995. In this way, it was possible to bring together contributions from a wide range of fields including phytopathology, genetics, bacteriology, plant breeding, plant protection, and taxonomy. This book is not intended simply as a record of the proceedings of the Berlin Conference, but as an extension of recent findings and hypotheses put forward at the meeting. All papers published in this volume have been reviewed by the Editors.