Simply put, allelopathy refers to an ecological phenomenon of plant-plant interference through release of organic chemicals (allelochemicals) in the environment. These chemicals can be directly and continuously released by the donor plants in their immediate environment as volatiles in the air or root exudates in soil or they can be the microbial degradation products of plant residues. The chemicals may interfere with survival and growth of neighboring or succeeding plants. Black walnut, eucalyptus, sunflower, sorghum, sesame and alfalfa are common examples of plants with allelopathic property as well as some staple crops such as rice, wheat, barley and sorghum. Plants can emit chemicals that also discourage insects and pathogens. To maintain sustained productivity, knowledge of this form of plant interference on other plants and on disease causing organisms has been used in agriculture since prehistoric time by manipulating cropping pattern and sequence such as mixed cropping and crop rotation. However, use of numerous agrochemicals including a wide range of herbicides, pesticides, fertilizers and genetically modified high yielding crops has become the characteristic feature of modern industrial agriculture. Not only the sustainability of crop yield is called into question in this form of agriculture, the extensive long-term and often irreversible environmental degradation including ground water contamination and food safety associated with industrial agriculture are now of serious concern worldwide.

The objective is to report on the latest advances in allelopathy by inviting leading scientists to contribute in specific fields. The volume is organized under three major subsections: History of allelopathy, Allelochemicals, allelopathic mechanisms, and bioassays, and Application of allelopathy in agriculture and forestry. An emphasis is place on methodology and application, making it a truly practical reference.

Mycorrhizal fungi are microbial engines which improve plant vigor and soil quality. They play a crucial role in plant nutrient uptake, water relations, ecosystem establishment, plant diversity, and the productivity of plants. Scientific research involves multidisciplinary approaches to understand the adaptation of mycorrhizae to the rhizosphere, mechanism of root colonization, effect on plant physiology and growth, biofertilization, plant resistance and biocontrol of plant pathogens. This book discusses and goes into detail on a number of topics: the molecular basis of nutrient exchange between arbuscular mycorrhizal (AM) fungi and host plants; the role of AM fungi in disease protection, alleviation of soil stresses and increasing grain production; interactions of AM fungi and beneficial saprophytic mycoflora in terms of plant growth promotion; the role of AM fungi in the restoration of native ecosystems; indirect contributions of AM fungi and soil aggregation to plant growth and mycorrhizosphere effect of multitrophic interaction; the mechanisms by which mycorrhizas change a disturbed ecosystem into productive land; the importance of reinstallation of mycorrhizal systems in the rhizosphere is emphasized and their impact on landscape regeneration, and in bioremediation of contaminated soils; Ectomycorrhizae (ECM) and their importance in forest ecosystems and associations of ECM in tropical rain forests function to maintain tropical monodominance; in vitro mycorrhization of micro-propagated plants, and visualizing and quantifying endorhizal fungi; the use of mycorrhizae, mainly AM and ECM, for sustainable agriculture and forestry.

This book provides a comprehensive look at the field of plant virus evolution. It is the first book ever published on the topic. Individual chapters, written by experts in the field, cover plant virus ecology, emerging viruses, plant viruses that integrate into the host genome, population biology, evolutionary mechanisms and appropriate methods for analysis. It covers RNA viruses, DNA viruses, pararetroviruses and viroids, and presents a number of thought-provoking ideas.

Research on the interactions of plants and phytopathogenic fungi has become one of the most interesting and rapidly moving fields in the plant sciences, the findings of which have contributed tremendously to the development of new strategies of plant protection. This book offers insight into the state of present knowledge. Special emphasis is placed on recognition phenomena between plants and fungi, parasitization strategies employed by the phytopathogenic fungi, the action of phytotoxins, the compatibility of pathogens with host plants and the basic resistance of non-host plants as well as cultivar-specific resistance of host plants. Special attention is paid to the gene-for-gene hypothesis for the determination of race-specific resistance, its molecular models and to the nature of race non-specific resistance as well as the population dynamics of plants and the evolution of their basic resistance.

Advances in Rice Blast Research provides a complete overview of the research undertaken on the rice-blast pathosystem. This book gathers in one volume the most recent works on rice blast fungus genetics and molecular biology of pathogenicity, rice blast fungus population studies, and genetics and molecular biology of rice resistance to blast, including resistance gene cloning. It also presents the latest results on resistance breeding and resistance management strategies, epidemiology and disease management. This book is a must for plant pathologists and breeders working on rice blast and also to plant pathologists and breeders dealing with fungal diseases in general, because the rice-blast pathosystem is a model in plant pathology. Advances in Rice Blast Research provides a complete overview of the research undertaken on the rice-blast pathosystem. This book gathers in one volume the most recent works on rice blast fungus genetics and molecular biology of pathogenicity, rice blast fungus population studies, and genetics and molecular biology of rice resistance to blast, including resistance gene cloning. It also presents the latest results on resistance breeding and resistance management strategies, epidemiology and disease management. This book is a must for plant pathologists and breeders working on rice blast and also to plant pathologists and breeders dealing with fungal diseases in general, because the rice-blast pathosystem is a model in plant pathology.

This book is based mainly on invited and offered papers presented at the Second International Symposium on Bacterial and Bacteria-like Contaminants of Plant Tissue Cultures held at University College, Cork, Ireland in September 1996, with additional invited papers. The First International Symposium on Bacterial and Bacteria-like Contaminants of Plant Tissue Cultures was held at the same venue in 1987 and was published as Acta Horticulturae volume 225, 1988. In the intervening years there have been considerable advances in both plant disease diagnostics and in the development of structured approaches to the management of disease and microbial contamination in micropropagation. These approaches have centred on attempts to separate, spatially, the problems of disease transmission and laboratory contamination. Disease-control is best achieved by establishing pathogen-free cultures while laboratory contamination is based on subsequent good working practice. Control of losses due to pathogens and microbial contamination in vitro addresses, arguably, the most importance causes of losses in the industry; nevertheless, losses at and post establishment can also be considerable due to poor quality microplants or micro-shoots. In this symposium, a holistic approach to pathogen and microbial contamination control is evident with the recognition that micropropagators must address pathogen and microbial contamination in vitro, and diseases and microplant failure at establishment. There is increasing interest in establishing beneficial bacterial and mycorrhizal association with microplants in vitro and in vivo.

Containing an extensive range of photographs and authored by leading horticultural experts, "Diseases of Temperate Horticultural Plants" is an indispensable reference work for horticultural professionals, academics, students and crop producers as well as amateur horticulturists. The diseases of major crops are presented according to their classification, and the symptoms of each disease, causal pathogen and control measures for each condition are described. The crops covered include the major temperate horticultural crops, organized into easy-to-navigate sections divided into fruits, vegetables and ornamentals. Within fruits, apples and pears are discussed, as well as ribes and berries, cherries, peaches and plums, nut crops and rhubarb. The vegetable section covers salad crops, brassicas and crucifers, cucurbits, root vegetables, bulb crops, solanaceous vegetables and some herbs. The section on ornamental plants includes a wide range of ornamental garden plants, while a further section discusses diseases of turf grass and ornamental lawns. The book is user-friendly with practical, accessibly written entries organized into discrete sections. The comprehensive nature of this work makes it an invaluable addition to any horticulturist s library with content that will remain current for years to come."

Plant-Pathogen Interactions: Methods and Protocols provides key methods, approaches, and strategies to dissect the plant defense response. Addressing methods to identify and characterize plant resistance genes as well as pathogen-associated molecules that trigger the plant defense response, this volume creates a better understanding of the interactions between pathogens and their hosts, which will help to develop better methods for disease control in plants and animals.
Plant-Pathogen Interactions: Methods and Protocols reviews methods for engineering resistance to plant viruses, the utility of viral induced gene silencing and RNAi silencing, as well as advances in genomics and proteomics that have lead to new methods to identify genes and proteins. The protocols presented follow the successful Methods in Molecular Biology series format, each one offering step-by-step laboratory instructions, an introduction outlining the principle behind the technique, lists of equipment and reagents, and tips on troubleshooting and the avoidance of known pitfalls.
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In the summer of 1997 some twelve lecturers and sixty students met for ten days in Budapest Hungary in a NATO Advanced Studies Institute (ASI) to consider "New Scientific and Technical Aspects of Verification of the Biological and Toxin Weapons Convention." In many ways the meeting was ahead of its time. The Ad Hoc Group was only then about to move to the discussion of a rolling text of the Protocol to the Biological and Toxin Weapons Convention (BTWC). It had been mandated to negotiate the Protocol by the Special Conference which had considered the work of the VEREX process that had taken place following the 1991 Third Review Conference of the Convention. Now, in late 1999, after much further negotiation of the text of the Protocol we are moving towards the endgame of the negotiations. Nevertheless, the scientific and technical issues discussed in the ASI in Hungary continue to be of direct relevance to the verification of the Convention and will continue to be relevant as the eventual Protocol moves from agreement through a Preparatory Commission stage and into full implementation over the next several years. The papers in this volume are much as they were presented in Budapest both in order of presentation and in content. They were designed by the ASI co-directors, Professor Graham Pearson and Ambassador Tibor Toth (Chairman of the Ad Hoc Group) to provide an integrated overview and in-depth analysis of the issues at stake.

The family Trichodoridae was established by Thorne in 1935 but it remained of limited taxonomie interest until 1951 when Christie and Perry associated Trichodorus christie (now Paratrichodorus minor) with a "stubby root disease" that affected certain crops in Florida, USA and interest further increased from 1960 when P. pachydermus was implicated as a vector of the economically important tobacco raule virus. Such discoveries gave an impetus to studies on many aspects of the biology of trichodorid nematodes with a consequent proliferation of new species described from different parts of the world. The number of species increased from twelve in 1957 to a present day total exceeding eighty. This rapid expansion in the number of species was accompanied by several reappraisals of the taxonomy and systematies of the family, the most notable changes being the creation of the genus Paratrichodorus by Siddiqi in 1974 and the recognition of the monodelphic genera Monotrichodorus and Allotrichodorus respectively by Andrassy in 1976 and Rodriguez-M, Sher and Siddiqi in 1978. Reliable and unambiguous identification of taxa is dependent on the known reliability of a range of characters, whieh remains of paramount importance in taxonomy even when biochemical and molecular methodology is available. In this book each of the species, including synonyms and species inquirenda, that comprise the family Trichodoridae is re-described from meticulous mieroscopie examination of type specimens, material from official nematode collections and populations in the field.

Microbial toxins are secondary metabolites that accumulate in the organism and, to a large extent, are metabolically inactive towards the organism that produces them. The discovery of penicillin, a secondary metabolite of Penicillium notatum West (= P. chrysogenum Thom), in 1929 marked a milestone in the development of antibiotics (microbial toxins). In the intensive studies that followed this discovery, scientists chemically characterized several new molecules (toxins) from secondary metabolites of microbes, some having a definite function in causing pathogenesis in plants. Toxins are also known to playa significant role in inciting animal (human) and insect diseases and as plant growth regulators. Many common toxins have also been isolated from different microbes exhibiting a wide spectrum of biological activity. Toxins are broadly divisible into several characteristic groupings - polyketides, oxygen heterocyclic compounds, pyrons, terpenoidS, amino acids - diketopiperazines, polypeptides etc. Recent research has indicated that these toxins play an important role in plant pathogenesis, disease epidemics, plant breeding, biological control of plant pathogens and insect pests, induced resistance, plant-pathogen interactions etc. Toxins produced by weed pathogens are exploited as lead molecules in developing environmentally friendly herbicides.

In response to low iron availability in the environment most microorganisms synthesize iron chelators, called siderophores. Bacteria and fungi produce a broad range of structurally diverse siderophores, which all show a very high affinity for ferric ions.

"Microbial Siderophores" presents an up-to-date overview of the chemistry, biology and biotechnology of these iron chelators. Following an introduction to the structure, functions and regulation of fungal siderophores, several chapters focus on siderophores of pseudomonads. Here, the technique of siderotyping, which has proved to be a rapid, accurate and inexpensive tool for pseudomonad characterization and identification, is described. Further, the biological significance of siderophores of symbiotic fungi and the possible role of siderophores in pathogenesis are discussed. In addition to methodological approaches, chapters on the biotechnological production of siderophores and their application in promoting human and plant health are included.

Emphasis in this second volume of Advances in Downy Mildew Research is on the biology of compatible interactions, forecasting and epidemiology, host specialisation, genetic variability amongst pathogen populations, novel methods for detection and systematics, and induced resistance. Two chapters focus on the related oomycete Albugo candida, which shares many pathogenic characteristics with the downy mildews and provides a valuable comparative pathosystem. Contributions on specific downy mildews include Bremia lactucae, Peronospora destructor, Peronospora sparsa, Peronospora viciae, Plasmopara halstedii, Plasmopara viticola, Pseudoperonospora cubensis and Sclerospora graminicola. Review chapters on compatibility, forecasting and systematics consider a broader range of downy mildew fungi, and compare them with other oomycete and biotrophic pathogens. The book is relevant to anyone with an interest in these unique biotrophic pathogens, either in their own right as causes of damaging diseases or as model systems for research on host-pathogen interactions. It should be read by: students, teachers and researchers in academic and research institutes; research and development personnel in the agrochemical industries; agricultural and horticultural advisers, and other extension workers.

Among the Horticultural Crops, Fruits and Vegetables (FV) are of primary - portance as the key source of essential components in an adequate and balanced human diet. FV have supported largely the daily food requirement of mankind since ages and even before man learned to grow cereal crops systematically. Over the years, growing FV has been the mainstay of rural economy and has emerged as an indispensable part of agriculture world over, offering farmers a wide range of crops in varied topography and climate. In certain parts of the world, FV are the major dietary staple. Apart from being a rich source of vitamins and minerals, this sector also contributes significantly in economy of the region or the nation. The increased income from per unit area of FV is far ahead and can not be compared with that of cereal crops. A recent survey by the Economist revealed that the world population has - creased by 90 % in the past 40 years while food production has increased only by 25 % per head. With an additional 1. 5 billion mouth to feed by 2020, farmers worldwide have to produce 39 % more. Looking at the load of the future food requirement, the global increased production of FV during last few years has absorbed the additional food requirement and accordingly the eating habits are also changing and shifting - wards more consumption of these commodities worldwide.

Mycotoxins continue to be a very serious threat to human health and a major concern for those entrusted with regulatingthesafetyoffoodandfoodproducts.Infectionofcerealsandothercrops, notablegrapevine, byFusarium, Aspergillus andPenicillium are a world-wide problem and recent epidemics in Europe, the USA and Canada have focused attention on this problem. A previous Special Issue of the European Journal of Plant Pathology (108 (7) 2003) was concerned with the nature of these toxins and the fungi that can produce them. The aim of this publication is to review the environmental factors that in?uence the success of these fungi as pathogens and as organisms affecting stored products, and to discuss how these factors can also in?uence the amounts of toxin that accumulate. These reviews were originally presented at a Workshop of the EU COST Action 835 entitled 'Agriculturally Important Toxigenic Fungi' (Chairperson Antonio Logrieco, Bari, Italy), held in East Malling, UK at the Horticultural Research International in September 2002. We hope the information provided will stimulate scientists world-wide to assess the risk of toxins accumulating in plants under a range of environmental conditions and that this will provide an insight into how the accumulation of these toxins can be kept to a minimum. XiangmingXu JohnBailey MichaelCooke EuropeanJournalofPlantPathology109: 645-667, 2003. (c) 2003KluwerAcademicPublishers.

Mechanisms and Deployment of Resistance in Trees to Insects is a worldwide synthesis of tree resistance to insects. The contributions are by senior scientists and represent all the major forested regions of the world. The book constitutes a comprehensive treatment of the state of our knowledge on patterns of resistance by insect guilds and how this knowledge can be deployed to achieve the management of damaging forest insects. This book will serve as an essential reference book for all researchers and practitioners attempting to manage forest pests using genetic resistance.

Major Fungal Diseases of Rice: Recent Advances provides a comprehensive overview of latest research in rice fungal pathology. There are 25 chapters dealing with the blast, sheath blight, sheath rot, brown spot and scald diseases of rice as well as some broader topics. The book covers recent progress in a number of key fundamental aspects such as pathogenicity, pathogen diversity, molecular characterisation, gene cloning, genetics of host resistance and host-pathogen interactions. It also presents the current status and perspectives in strategic and applied areas such as epidemiology, resistance breeding, biological control, induced resistance, seed-borne diseases and quarantine issues and disease management strategies. This book is essential for rice researchers, pathologists and breeders and will also be suitable for cereal and plant pathologists in general, as there is an extensive coverage of recent research advances in rice blast, a model system in plant pathology.

Each plant-pathogen interaction involves a two-way molecular communication. On one hand, the pathogen perceives signals from the plant, secretes chemical arsenals to establish infection courts, and produces metabolites that disrupt structural integrity, alter cellular function, and circumvent host defenses. On the other hand, the plant senses the signals from the pathogen, reinforces its cell walls, and accumulates phytoalexins and pathogenesis-related proteins in an attempt to defend itself. The production of pathogenicity and virulence factors by the pathogen, the elicitation of defense mechanisms by the plant, and the dynamic interaction of the two are the focal points of this book. The book will be of interest to researchers and advanced undergraduate and graduate students in the areas of plant pathology, plant physiology, and plant biochemistry.

Straminipilous Fungi presents a critical comparative review of the morphology and ultrastructure, morphogenesis, cytology, molecular biology and evolution of the biflagellate fungi. These organisms encompass the fungi formerly called oomycetes; taxonomically related heterotrophs studied by mycologists; plasmodiophorids and other heterotrophs. Appropriate comparisons are made with chromophyte algae, marine heterotrophs and chytridiaceous fungi. Little-known taxa which have been referred to the various orders of flagellate fungi are also listed together with citations. A new hierarchical classification is presented which is supported by systematic accounts and synoptic keys. Dichotomous keys based on habitat and habit are given to all known species of lagenidiaceous fungi, labyrinthulids and plasmodiophorids. A unique 'one stop' reference resource for plant pathologists is provided by the binominal lists, including host-related lists for the downy mildews. The book, including ca 4000 references, is a major text for post-graduate and research workers, particularly freshwater and marine biologists, soil ecologists and plant pathologists.

Wheat breeders have achieved significant results over the last fifty years in research on mankind's one of the most important crops. Classical genetic and breeding methods, far broader international cooperation than was experienced in earlier periods, and improvements in agronomic techniques have led to previously unimaginable development in the utilisation of wheat for human consumption. The contribution of wheat researchers is particularly noteworthy since these results have been achieved at a time when the world population has grown extremely dynamically. Despite this demographic explosion, of a proportion never previously experienced, thousands of millions of people have been saved from starvation, thus avoiding unpredictable social consequences and situations irreconcilable with human dignity. Despite these developments in many regions of the world food supplies are still uncertain and the increase in the world's wheat production has not kept pace with the population increase during the last decade. Due to the evils of civilisation and the pollution of the environment there is a constant decline in the per capita area of land suitable for agricultural production. Based on population estimates for 2030, the present wheat yield of around 600 million tonnes will have to be increased to almost 1000 million tonnes if food supplies are to be maintained at the present level.

Induced or acquired resistance to disease in plants has been known for many years, but the phenomenon was studied in only a few laboratories until about a decade ago. Since then, there has been an increasing interest in induced resistance as a new, environmentally safe means of disease control, as well as a model for the study of the genes involved in host defence and the signals that control them. This increased interest led the editors of Induced Resistance to Disease in Plants to collect and summarise much of the current and older literature on the topic in a single volume. Each chapter covers its topic as comprehensively as possible, thus serving as a solid introduction to the literature, as well as expressing its writer's own views on the state of research in the area and giving an indication of where future research may lead. Induced Resistance to Disease in Plants addresses the biology of induced resistance in legumes, solanaceae, cucurbits and monocots, since these are the families that have received the most attention, followed by a discussion of the molecular basis of induced resistance, its genetic and evolutionary significance, and practical applications in disease control. The book will provide a background for those commencing work in the area, as well as a source of information for established workers who wish to learn about other areas of induced resistance.

This, the first volume of the Integrated Management of Plant Pests and Diseases book series, presents general concepts on integrated pest and disease management. Section one includes chapters on infection models, resurgence and replacement, plant disease epidemiology and effects of climate change in tropical environments. The second section includes remote sensing and information technology. Finally, the third section covers molecular aspects of the subject."

This volume explores modern concepts of trophic and guild interactions among natural enemies in natural and agricultural ecosystems - a field that has become a hot topic in ecology and biological control over the past decade. It is the first book on trophic and guild interactions to make the link to biological control, and is compiled by internationally recognized scientists who have combined their expertise.

For a long time there has been a critical need for a book to assess the genomics of tropical plant species. At last, here it is. This brilliant book covers recent progress on genome research in tropical crop plants, including the development of molecular markers, and many more subjects. The first section provides information on crops relevant to tropical agriculture. The book then moves on to lay out summaries of genomic research for the most important tropical crop plant species.

Biological control of plant diseases and plant pathogens is of great significance in forestry and agriculture. This book, the first of its kind, is organized around the indication that allelochemicals can be employed for biological control of plant pathogens and plant diseases. This volume focuses on discovery and development of natural product based fungicides for agriculture, direct use of allelochemicals, and application of allelopathy in pest management.