In the years since the first edition of “Arbuscular Mycorrhizas: Physiology and Function” was published, an exceptional proliferation of interest in mycorrhizal biology has developed. This has been associated with advances in different research disciplines such as genetics, genomics, proteomics, metabolomics and physiology, advances which have generated better insight into topics of mycorrhizal biology, including the mechanisms of host-mycorrhiza interactions pre- and post-penetration, the influence of the symbiosis on the host and its surroundings, and the evolution and diversity of mycorrhization. It therefore became necessary to both update and expand the book's coverage in this, its second edition.

Recent years have brought an upsurge of interest in the study of arbuscular mycorrhizal (AM) fungi, partly due to the realization that the effective utilization of these symbiotic soil fungi is likely to be essential in sustainable agriculture. Impressive progress has been made during the last decade in the study of this symbiosis largely as a result of increasing exploitation of molecular tools. Although early emphasis was placed on the use of molecular tools to study physiological processes triggered by the symbiosis, such as expression of symbiosis-specific polypeptides and modulation of host defences, other applications await. It was obvious to us that gathering leaders in the field to summarize these topics and point out research needs was necessary if we were to understand the physiology and function of AM fungi at a molecular level. In addition, we have taken the opportunity to present these reviews in a logical sequence of topics ranging from the initiation of the life cycle of the fungus to its functions in plant growth and in the below ground ecosystem. It was a challenge to limit this flood of information to the confines of one text. This is a very exciting time for mycorrhiza biologists and it is our hope that some of this excitement is conveyed to our readers.

The second edition of Mycorrhiza falls into a time period of excep tionally rapid growth in mycorrhizal research. Therefore the edi tors have been most pleased with the decision of the Springer Verlag to revise the first edition and to incorporate the remarkable advances experienced in the mycorrhizal field. The pace of discovery has been particularly fast at the two poles of biological complexity, the molecular events leading to changes in growth and differentiation, as well as the factors regulating the structure and diversity of natural populations and communities. Therefore the most significant changes introduced in the new edition of this book are found within these topics. Not only were many chapters up dated, but also new chapters have replaced existing ones. The individual decisions have not been easy, since valuable contribu tions had to be sacrificed in favour of new aspects; but the authors hope that a highly topical new edition will be of greatest benefit for a rapidly expanding field of research. We welcome comments and critics from readers. Since it was possible again to find leading scientists as contribu tors, we are confident that this revised second edition will stimulate further progress and contribute to a deeper understanding of advances in the mycorrhizal field. We are grateful to the Springer Verlag, especially Dr. Dieter Czeschlik, for his continued interest and active help. Dr. Maja Hilber-Bodmer and Dr.

The roots of most plants are colonized by symbiotic fungi to form mycorrhiza, which play a critical role in the capture of nutrients from the soil and therefore in plant nutrition. Mycorrhizal Symbiosis is recognized as the definitive work in this area. Since the last edition was published there have been major advances in the field, particularly in the area of molecular biology, and the new edition has been fully revised and updated to incorporate these exciting new developments. - Over 50% new material - Includes expanded color plate section - Covers all aspects of mycorrhiza - Presents new taxonomy - Discusses the impact of proteomics and genomics on research in this area

This book provides up-to-date knowledge of root biology. Most plants have roots, which anchor the plant in the soil and physically support the above-ground parts of the plant. In addition, roots absorb water and nutrients from the soil and transport this to the shoot. Roots grow by cell proliferation in the meristem in the root tip. The cells differentiate into the epidermis, cortex, and stele. Water and nutrients are absorbed through the cell membrane of the epidermis and are transported to the above-ground parts via xylem vessels. The root growth and functions are affected by various abiotic and biotic conditions, such as levels of water, salt, acid stresses, and presence of soil diseases. However, some beneficial microorganisms such as rhizobia and mycorrhizal fungi help plant growth.

This book, prepared by participants of the European network COST ACTION 810 (1989-93) is the outcome of a meeting held in Switzerland (Einsiedeln, September 29 to October 2, 1993) on the "Impact of arbuscular mycorrhizas on sustainable agriculture and natural ecosystems". COST(Cooperation Scientifique et Technique) Networks were created in 1971 by the Commission of European Communities, and later enlarged to include non-European Member States, to promote pre-competitive scientific and technical research in fields of common interest. During the eighties, COST ACTIONS were launched in bio technological fields, including the network on arbuscular mycorrhizas. Arbuscular mycorrhizas are a universally found symbiosis between plants and certain soil fungi and essential components of soil-plant systems. They act as a major inter face by influencing or regulating resource allocation between abiotic and biotic components of the soil-plant system. Arbuscular mycorrhizas are involved in many key ecosystem processes including nutrient cycling and conservation of soil struc ture, and have been shown to improve plant health through increased protection against abiotic and biotic stresses. Sustainability can be defined as the successful management of resources to satisfy changing human needs while maintaining or enhancing the quality of the environ ment and conserving resources. Increasing environmental degradation and instability, due to anthropogenic activities and in particular the increasing fragility of the soil resource, has led to an increased awareness of the need to develop practices resulting in more sustainable natural and agroecosystems.

Taxonomy of the fungi forming endomycorrhizae; Morphology and histology of vesicular-arbuscular mycorrhizae; Methods for the recovery and quantitative estimation of propagules from soil; Quantification of vesicular-arbuscular mycorrhizae in plant roots; Production of endomycorrhizal inoculum; Procedures for inoculation of plants with vesicular-arbuscular mycorrhizae in the laboratory, greenhouse and field; Evaluationof plant response to colonization by vesicular-arbuscular mycorrhizal fungi; Spore germination and axenic culture of endomycorrhizae; Taxonomy of ecto- and ectendomycorrhizal fungi; Morphology and development of ecto- and ectendomycorrhizae; Isolation, maintenance, and pure culture manipulation of ectomycorrhizal fungi; Production of ectomycorrhizal fungus inoculum; Ectomycorrhizal inoculation procedures for greenhouse and nursery studies; Quantitative measurement of ectomycorrhizae on plant roots; Evaluation of plant response to inoculation; Radiotracer methods for mycorrhizal research; Electron mycroscopy of mycorrhizae; Mycorrhizae in interactions with other microorganisms.