Mohammad Saghir Khan l Almas Zaidi Javed Musarrat Editors Microbes for Legume Improvement SpringerWienNewYork Editors Dr. Mohammad Saghir Khan Dr. Almas Zaidi Aligarh Muslim University Aligarh Muslim University Fac. Agricultural Sciences Fac. Agricultural Sciences Dept. Agricultural Microbiology Dept. Agricultural Microbiology 202002 Aligarh 202002 Aligarh India India [email protected] [email protected] Prof. Dr. Javed Musarrat Aligarh Muslim University Fac. Agricultural Sciences Dept. Agricultural Microbiology 202002 Aligarh India [email protected] This work is subject to copyright. All rights are reserved, whether the whole or part of the material is concerned, specifically those of translation, reprinting, re-use of illustrations, broadcasting, reproduction by photocopying machines or similar means, and storage in data banks. Product Liability: The publisher can give no guarantee for all the information contained in this book. The use of registered names, trademarks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. # 2010 Springer-Verlag/Wien Printed in Germany SpringerWienNewYork is a part of Springer Science+Business Media springer.at Typesetting: SPI, Pondicherry, India Printed on acid-free and chlorine-free bleached paper SPIN: 12711161 With 23 (partly coloured) Figures Library of Congress Control Number: 2010931546 ISBN 978-3-211-99752-9 e-ISBN 978-3-211-99753-6 DOI 10.1007/978-3-211-99753-6 SpringerWienNewYork Preface The farmer folks around the world are facing acute problems in providing plants with required nutrients due to inadequate supply of raw materials, poor storage quality, indiscriminate uses and unaffordable hike in the costs of synthetic chemical fertilizers. Beside these factors, the fertility of soil, largely dependent on metabolic activities of microbes, is deteriorating very fast, which further aggravate the agronomic problems. Considering such alarming situations, there is an urgent need to find an alternative so that the chemical based high input modern agricultural practices could be shifted to an economically viable, ecologically sound, and sustainable production system. In this regard, heterogeneously distributed microbial communities play a vital role as organic fertilizers in facilitating uptake of nutrients by crops. Hence, provides a viable and inexpensive alternative to offset dependence on chemical fertilizers applied in modern agriculture on large scale by majority of the progressive farmers around the world for raising the productivity of crops including legumes. Legumes that play an important role in the traditional diets of many regions throughout the world can provide a multitude of benefits to both the soil and other crops grown in combination with them or following them in a rotation. The ability of legumes to fix atmospheric nitrogen is perhaps the most bodacious countenance that distinguishes them from other plants. In addition, legumes can provide a wide range of important soil quality benefits, like, it increases soil organic matter, improve soil structure and porosity, recycle nutrients, decrease soil pH, diversify the rhizosphere microbes and break disease build-up. Application of microbial inoculants very commonly used for legumes, as a component of organic cultivation is therefore, an exciting area for enhancing legume production and has also been suggested as an alternative control measure for mitigation of environmen- tal pollution. Plethora of experiments have been conducted to better understand the impact of naturally abundant microbes in the improvement of legumes but a meagre efforts are made to compile them. Microbes for legume improvement written by experts in the field provide unique, updated and comprehensive information on how microbial communities could be exploited and practiced for increasing the productivity of legumes in varied production systems in different geographical regions of the world. The book presents the recent developments in the rhizobial taxonomy and discusses v vi Preface the symbiotic features of rhizobia scrutinizing the frontier of legumes and bacteria promiscuity. Various factors including the exchange of plant and bacterial signaling molecules, such as, flavonoids and nodulation factor (Nod factor), in the early stages of symbiosis that influence symbiotic rhizobial interactions under competi- tive soil environment, is highlighted. The information relative to proteomic control of legume-rhizobium interaction is explored in a chapter on the role of proteomics in legume-rhizobium symbiosis. The role of ethylene and bacterial ACC-deaminase in legume-rhizobium interaction are also broadly covered in this book. The current developments in the field of soil bacterial biofilms, bacterial functions influencing biofilm formation, effects of exopolysaccharides, quorum sensing, rhizobial pro- teins, and motility on bacterial biofilms and development, and application of biofilmed biofertilizers in legume improvement are discussed separately. The book further describes as to how the plant growth promoting rhizobacteria either alone or in association with nitrogen fixing bacteria facilitate the growth and nutrient uptake by legumes and how such microbial strategies could be exploited for better productivity of legumes in different agro-ecological regions, are eluci- dated in greater detail. The interactions/relationships of rhizosphere bacteria with their hosts and performance of wild-type and genetically manipulated beneficial bacterial populations are discussed for their efficient utilization in legume produc- tion under sustainable agriculture systems. Phosphorus and its effect on the envi- ronment have become hotly contested issues. This book provides a broad and updated view of the strategic and applied research conducted so far to understand as to how phosphate solubilizing bacteria either alone or in synergisms with other symbionts could help to manage phosphorus problems in phosphorus deficient soils, and ultimately enhance nutrient availability, and concomitantly improve the yields of legumes. The mycorrhizosphere interactions for legume improvement, mycorhhizal dependency of legumes, the mechanisms as to how mycorhiza pro- motes legume growth and consequential impact of mycorrhiza either alone or in combination with other beneficial microbes on legume improvement in conven- tional or desertified and/or degraded habitats is described. Given the importance of legumes in animal and human consumption and their role in maintaining soil fertility, attention is paid to understand how rhizobia develops resistance to various stressor molecules and how such tolerant naturally gifted microbes could become handy in sustaining the productivity of legumes in the stressed soils. The role of asymbiotic Azosprillum either alone or as mixture with other plant growth promot- ing rhizobacteria (PGPR) in increasing the productivity of legumes are highlighted. The current status of symbiotic nitrogen fixation (SNF) in tropical food grain legumes and strategies adopted for the management of pathogens affecting severely the productivity of legumes, employing plant growth promoting rhizobacteria are well explained. This book collectively provides some novel microbial strategies and proposes alternative solution, which if properly applied could help to boost the overall performance of legumes while reducing the dependence on synthetic agro- chemicals. The knowledge and methodologies described in this book offer invalu- able research tools, which may serve as an important and updated source material. This edition provides an authoritative overview for individuals interested in legume Preface vii research. This book will therefore, be of great interest to the research scientists, postgraduate students, bioscience professionals, decision makers, and farmers who intend to use the naturally gifted wonderful microbes for the improvement of legumes. It would also serve as a valuable resource for agronomists, soil micro- biologists, soil scientists, biologists, and biotechnologists involved in nutrient management and legume research. We are deeply indebted to our well qualified and internationally renowned colleague authors from different countries for providing the important, authoritative and cutting-edge scientific information to make this book a reality. All chapters are well illustrated with appropriately placed tables and figures, and enriched with extensive and most recent references. The help and support provided by research scholars working with us in designing and preparing some of the drawings pre- sented in this book are greatly acknowledged. We are indeed very grateful to our family members for their untiring and sustained support, who, in their own ways inspired us and, subconsciously contributed a tremendous amount to the outcome of this book. We appreciate the great efforts of book publishing team at Springer- Verlag, Austria, in responding to all our queries very promptly and without delay during our ongoing academic/scientific relationship. Finally, this book may have some basic mistakes or printing errors happening accidentally during preparation, for which we regret in anticipation. If pointed out at any stage, we will certainly try to correct and improve them in subsequent print/edition. Suggestions and critical analysis of the contents presented in this book by the readers are most welcome. Mohammad Saghir Khan Almas