Allelopathy is an ecological phenomenon by which plants release organic chemicals (allelochemicals) into the environment influencing the growth and survival of other organisms. In this book, leading scientists in the field synthesize latest developments in allelopathy research with a special emphasis on its application in sustainable agriculture. The following topics are highlighted: Ecological implications, such as the role of allelopathy during the invasion of alien plant species; regional experiences with the application of allelopathy in agricultural systems and pest management; the use of microscopy for modeling allelopathy; allelopathy and abiotic stress tolerance; host allelopathy and arbuscular mycorrhizal fungi; allelopathic interaction with plant nutrition; and the molecular mechanisms of allelopathy. This book is an invaluable source of information for scientists, teachers and advanced students in the fields of plant physiology, agriculture, ecology, environmental sciences, and molecular biology.

Morphological, biological, biochemical and physiological characteristics have been used for the detection, identification and differentiation of fungal pathogens up to species level. Tests based on biological characteristics are less consistent. Immunoassays have been shown to be effective in detecting fungal pathogens present in plants and environmental samples. Development of monoclonal antibody technology has greatly enhanced the sensitivity and specificity of detection, identification and differentiation of fungal species and varieties/strains. Nucleic acid-based techniques involving hybridization with or amplification of unique DNA have provided results rapidly and reliably. Presentation of a large number of protocols is a unique feature of this volume.

Bemisia tabaci (Gennedius) has distinguished itself from the more than 1,000 whitefly species in the world by its adaptability, persistence and potential to damage a wide range of agricultural and horticultural crops in all six of the world's inhabited continents. B. tabaci inflicts plant damage through direct feeding, inducement of plant disorders, vectoring of plant viruses and excretion of honeydew. This book collates multiple aspects of the pest ranging from basic to applied science and molecular to landscape levels of investigation. Experts in multiple disciplines provide broad, but detailed summaries and discussion of taxonomy, genetics, anatomy, morphology, physiology, behavior, ecology, symbiotic relationships, virus vector associations and various tactics for integrated management of this pest insect. The book is focused primarily on progress during the last 10-15 years and is directed at workers in the field as well as the informed professional who may not necessarily specialize in whitefly research. The book is unique in providing broad coverage in relatively few chapters by recognized experts that highlight the state-of-the-art in our understanding of this fascinating but troublesome cosmopolitan pest.

Malformation disease of mango (Mangifera indica) initially noted in patches in India has now turned into a global menace wherever mango is grown. The challenge posed by the problem attracted interest of Scientists from various disciplines, continue to do so, and will attract their attention until the problem is understood threadbare, and resolved. For a long time, due to complex nature of the disease, the cause and causal agent was both hotly debated. Only in recent years, the issue of the etiology of the disease has been resolved, epidemiology has been worked out to a large extent and silver bullet control measures have been replaced by IPM strategy based on the information generated on the physiology of pathogenesis and epidemiology of the disease.

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.

There is an urgent need to expand our knowledge of both the nature of the toxigenic fungi that are widespread on economically-important plants and the effect of their toxic secondary metabolites on human health. Informa tion about the production of mycotoxins by plant pathogens, particularly by species of Fusarium, Aspergillus and Penicillium, their occurrence in infected plants, as well as their role in the plant-pathogen interaction, for example as virulence/pathogenicity factors, is a pre-requisite for preventing plant disease and hence for reducing the Ievels of mycotoxin contamination. Fusarium infections in cereals and other crops are a particular problern world-wide and recent epidemics on wheat in Europe, the USA and Canada have again focused attention on this problem. Fur thermore, species ofAspergillus and Penicillium and their related mycotoxins, particularly Ochratoxin A, represent another consistent problern on cereals and grapes, especially in Europe where 40% of the global grape crop is grown. The aim of this publication is to gather together specialist updated reviews based on papers originally presented during a Workshop of EU Cost Action 835 entitled 'Agriculturally Important Taxigenie Fungi', held in Rome, 7-8 October 1999 at the Plant Pathology Research Institute. We hope the diversity of the contents will stimulate discussion, encourage the sharing of information and result in cross-fertilization of ideas needed for the solution of the present problems. This special issue will be of particular value to interdisciplinary scientists and especially mycologists, mycotoxicologists, plant pathologists and those concerned about the quality of food and food products.

Plant Pathogenic Bacteria includes symposia and research papers presented at the 10th International Conference on Plant Pathogenic Bacteria. The book provides the complete text of 22 symposia papers that summarize the state-of-the-art of the many facets of phytobacteriology including disease control, taxonomy, genetics of pathogenicity, virulence factors, as well as detection and diagnosis. These topics are also included among research papers, presented orally or as posters at the conference, and here presented in research paper format, conveniently separated in different sections by subject matter. This book will be an essential resource for scientists and students with an interest in plant pathogenic bacteria for it provides much new data and summarizes current thinking in almost all areas of the science. Nowhere else can one find so much information on plant pathogenic bacteria in a single resource.

This is a comprehensive up-to-date treatise including information on virus-, viroid-, and phytoplasma-induced potato diseases. The chapters of this book were written by internationally well-known experts and include novel techniques of detection, virus isolation, transmission, and epidemiology of the pathogens.

Precise regulation of gene expression in both time and space is vital to plant growth, development and adaptation to biotic and abiotic stress conditions. This is achieved by multiple mechanisms, with perhaps the most important control being exerted at the level of transcription. However, with the recent discovery of microRNAs another ubiquitous mode of gene regulation that occurs at the post-transcriptional level has been identified. MicroRNAs can silence gene expression by targeting complementary or partially complementary mRNAs for degradation or translational inhibition. Recent studies have revealed that microRNAs play fundamental roles in plant growth and development, as well as in adaptation to biotic and abiotic stresses. This book highlights the roles of individual miRNAs that control and regulate diverse aspects of plant processes.

Experience shows that biotic stresses occur with different levels of intensity in nearly all agricultural areas around the world. The occurrence of insects, weeds and diseases caused by fungi, bacteria or viruses may not be relevant in a specific year but they usually harm yield in most years. Global warming has shifted the paradigm of biotic stresses in most growing areas, especially in the tropical countries, sparking intense discussions in scientific forums. This book was written with the idea of collecting in a single publication the most recent advances and discoveries concerning breeding for biotic stresses, covering all major classes of biotic challenges to agriculture and food production. Accordingly, it presents the state-of-the-art in plant stresses caused by all microorganisms, weeds and insects and how to breed for them. Complementing Plant Breeding for Abiotic Stress Tolerance, this book was written for scientists and students interested in learning how to breed for biotic stress scenarios, allowing them to develop a greater understanding of the basic mechanisms of resistance to biotic stresses and develop resistant cultivars.

G proteins are the key regulators for a wide range of cellular processes in animals and plants. In comparison to animals and yeast, plants have a single Rho-GTPase subfamily called Rho-like GTPases (ROPs). The ROP family of monomeric GTPases has emerged as a versatile and key regulator in plant signal transduction processes. During the past few years' studies on plant RHO-type (ROP) GTPase have generated new insights into their role in diverse processes ranging from cytoskeletal organization, polar growth, development to stress and hormonal responses. Studies have shown that plants have evolved specific regulators and effector molecules. ROP GTPases possess the ability to interact with these multiple regulator and effector molecules that ultimately determines their signaling specificity. Recently, genome wide studies in plants have shown that the Arabidopsis genome encodes 93, and rice has nearly 85 small GTPase homologs. And we have been able to identify four new homologs in the rice genome. Here, we focus on the complete phylogenetic, domain, structural and expression analysis during stress and various developmental processes of small GTPases in plants. The comparison of gene expression patterns of the individual members of the GTPase family may help to reveal potential plant specific signaling mechanisms and their relevance. Also, we are summarizing the role of currently known ROP GTPases and their interacting proteins with brief description, simultaneously, comparing their expression pattern based on microarray data. Overall, we will be discussing the functional genomic perspective of plant Rho like GTPases and their role in regulating several physiological processes such as stress, hormonal, pollen tube, root hair-growth and other developmental responses.

This volume covers the high relevance of fungi for agriculture. It is a completely updated and revised second edition with fourteen excellent chapters by leading scientists in their fields and offers a comprehensive review of the latest achievements and developments. Topics include: Food and fodder; fungal secondary metabolites and detoxification; biology, disease control and management; symbiontic fungi and mycorrhiza; and phytopathogenicity.

The offered volume intends to review the biological control theme of phytonematodes from several prospects: ecological; applicative as well as commercial state of the art; understanding the mode-of-action of various biocontrol systems; interaction between the plant host, nematodes surface and microorganism s; candidates for biocontrol; extrapolation of the wide knowledge existed in another systems for understanding biocontrol processes: "C. elegans" as a model and lessons from other natural systems; and exploiting advanced genomic tools to promote understanding biocontrol processes and thereafter improve specific biological control agents.

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The explosive increase in the world's human population, with conse quent need to feed an ever-increasing number of hungry mouths, and the largely resultant disturbances and pollution of the environment in which man must live and produce the things he needs, are forcing him to search for means of solving the first problem without intensifying the latter. Food production requires adequate assurance against the ravages of insects. In the last three decades short-sighted, unilateral and almost exclusive employment of synthesized chemicals for insect pest control has posed an enormous and as yet unfathomed contribution to the degradation of our environment, while our insect pest problems seem greater than ever. Properly viewed, pest control is basically a question of applied ecology, yet its practice has long been conducted with little regard to real necessity for control, and in some cases, with little regard to various detrimental side-effects or long-term advantage with respect, even, to the specific crop itself. This book deals fundamentally with these questions. The development of pesticide resistance in many of the target species, against which the pesticides are directed, has occasioned an ever-increasing load of applications and complexes of different kinds of highly toxic materials. This has been made even more "necessary" as the destruction of natural enemies has resulted, as a side effect, in the rise to pest status of many species that were formerly innocuous. The application of broad-spec trum pesticides thus has many serious and self-defeating features."

Our view of plants is changing dramatically. Rather than being only slowly responding organisms, their signaling is often very fast and signals, both of endogenous and exogenous origin, spread throughout plant bodies rapidly. Higher plants coordinate and integrate their tissues and organs via sophisticated sensory systems, which sensitively screen both internal and external factors, feeding them information through both chemical and electrical systemic long-distance communication channels. This revolution in our understanding of higher plants started some twenty years ago with the discovery of systemin and rapid advances continue to be made. This volume captures the current 'state of the art' of this exciting topic in plant sciences.

Since the publication of the first edition of "The Mycota Vol. V Plant Relationships" in 1997, tremendous advances in fungal molecular biology and biochemistry have taken place; and both light and electron microscopical techniques have improved considerably. These new insights led to a better understanding of the relationships between fungi and plants; and a completely revised new edition of Plant Relationships could be produced, providing an up-to-date overview on mutualistic and pathogenic interactions.

In 18 chapters internationally acknowledged authors present reviews on fungal lifestyles, mechanisms of their interactions with their host plants, signal perception and transduction, and plant defense responses directed against attack by fungal pathogens.

Highlighting the recent developments in fungus-plant interactions, this volume is indispensable for researchers, lecturers and students in microbiology, mycology and plant sciences, including plant pathology."

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.

The book provides a fascinating overview about current and sophisticated developments in applied entomology that are powered by molecular biology and that can be summarized under a novel term: insect biotechnology. By analogy with the application of powerful molecular biological tools in medicine (red biotechnology), plant protection (green biotechnology) and industrial processing (white biotechnology), insect biotechnology (yellow biotechnology) provides novel tools and strategies for human welfare and nutrition. Insect Biotechnology has emerged as a prospering discipline with considerable economic potential, and encompasses the use of insect model organisms and insect-derived molecules in medical research as well as in modern plant protection measures.

Many fungi and bacteria that associate with plants are potentially harmful and can cause disease, while others enter into mutually beneficial sym bioses. Co-evolution of plants with pathogenic and symbiotic microbes has lead to refined mechanisms of reciprocal recognition, defense and counter defense. Genes in both partners determine and regulate these mechanisms. A detailed understanding of these genes provides basic biological insights as well as a starting point for developing novel methods of crop protection against pathogens. This volume deals with defense-related genes of plants and their regulation as well as with the genes of microbes involved in their interaction with plants. Our discussion begins at the level of populations and addresses the complex interaction of plant and microbial genes in multigenic disease resistance and its significance for crop protection as compared to mono genic resistance (Chap. 1). Although monogenic disease resistance may have its problems in the practice of crop protection, it is appealing to the experimentalist: in the so-called gene-for-gene systems, single genes in the plant and in the pathogen specify the compatibility or incompatibility of an interaction providing an ideal experimental system for studying events at the molecular level (Chaps. 2 and 4). Good progress has been made in identifying viral, bacterial, and fungal genes important in virulence and host range (Chaps. 3-6). An important aspect of plant-microbe interactions is the exchange of chemical signals. Microbes can respond to chemical signals of plant origin."

The molecular mechanisms which determine whether the cells of a multicellular organism will live or commit suicide have become a popular field of research in biology during the last decade. Cell death research in the plant field has also been expanding rapidly in the past 5 years. This special volume of Plant Molecular Biology seeks to bring together examples of a diverse array of experimental approaches in a single volume. From the differentiation of tracheary elements in vascular plants to the more specialized cell death model of the aleurone in cereals, this volume will bring the reader up-to-date with the characterization of different plant model systems that are currently being studied. This endeavor should complement general overviews of plant cell death mechanisms that have been published elsewhere by providing more detailed information on various aspects of this field to interested graduate students and more senior biologists alike.

Food legumes (pulses) playa role in human nutrition and more recently as animal feed, in the developing world. They contain minerals and vitamins essential for a balanced diet in humans. In many developing countries food legumes provide the necessary protein and amino acids (in predominantly vegetarian India, Bangladesh, Nepal, Myanmar and Sri Lanka) and supplement the protein diet of people in other countries. Since 1980-82 per capita consumption has declined by 6 % in developing countries where relative pulse prices have gone up and consumption of animal protein (eg milk) has increased. The importance of legumes as animal feed is increasing. The compound growth rate for feed use during 1980-95 was 7. 97% compared to 1. 5% growth for food use during the same period (Kelly et aI. , 1997). As an integral part of farming systems, food legumes, in rotation with cereals and tuber crops, assist in maintaining soil fertility and the sustainability of production systems (Rego et aI. , 1996). Owing to higher prices in comparison with cereals, food legumes are increasingly being grown to supplement farmers' incomes. The major food legumes grown in developing countries are: dry bean (Phaseolus vulgaris), faba bean (Vicia faba), dry pea (Pisum sativum), chickpea (Cicer arietinum), lentil (Lens culinaris), mung bean (Vigna radiata), black gram (Vigna mungo) pigeonpea (Cajanus cajan) and Lathyrns ( Lathyrus sativus). Oil crops such as groundnut (Arachis hypogaea) and soybean (Glycine max) are food legumes but are not discussed in this paper.

From February 24 -28, 1992 an international symposium on Durability of Disease Resistance was held at the International Agricultural Centre in Wageningen, the Netherlands. The symposium, organized by the Department of Plant Breeding of Wageningen Agricultural University and the Centre for Plant Breeding and Repro duction Research, CPRO-DLO, was part of the DGIS funded programme Durable Resistance in Developing Countries. Without any form of prevention or protection nearly all crops will be seriously or even severely damaged by a range of pathogens. In modern agriculture man has been able to control many if not most pathogens using i) pesticides, ii) phyto sanitary methods such as control of seed and plant material in order to start a crop disease free, iii) agronomic measures such as crop rotation, iv) disease resis tance or combinations of these measures. Over the years the use of pesticides has increased enormously and so did the pro blems associated with pesticide use, such as environmental pollution and building of resistance and tolerance to these pesticides in the pathogens. The use of resis tance too increased strongly over the years and here too problems arose.

To cope with the increasing problems created by agrochemicals such as plant fertilizers, pesticides and other plant protection agents, biological alternatives have been developed over the past years. These include biopesticides, such as bacteria for the control of plant diseases, and biofertilizer to improve crop productivity and quality. Especially plant growth promoting rhizobacteria (PGPR) are as effective as pure chemicals in terms of plant growth enhancement and disease control, in addition to their ability to manage abiotic and other stresses in plants. The various facets of these groups of bacteria are treated in this Microbiology Monograph, with emphasis on their emergence in agriculture. Further topics are Bacillus species that excrete peptides and lipopeptides with antifungal, antibacterial and surfactant activity, plant-bacteria-environment interactions, mineral-nutrient exchange, nitrogen assimilation, biofilm formation and cold-tolerant microorganisms.