C. Manoharachary – författare

The importance of mycorrhiza for the improvement of plant growth is increasingly being realised in Agriculture and Forestry and several mycorrhizal fungi have been commercially recognised for the purpose. The aim of this book is to describe the various techniques used to study the mycorrhizal biology. Problems with preparing such a book are many. Mainly mailing of manuscripts to and from authors resulted in irregular and final editing. Every effort was made not to change the peer review original manuscript to ensure accuracy. Our sole aims is to communicate to the greatest extent possible a current world need in mycorrhizal research. Plant productivity is regulated by microbial associations established in the plant root systems. The interactions of microorganisms and plant roots are especially important in providing nutritional requirements of the plant and the associated microorganisms. Plant growth and development are controlled largely by the soil environment in the root region -rhizosphere. This is a very complex environment in which the effects of the plant on soil microorganisms and the effects of microorganisms on the plant are interacting, interdependent and highly complex. Plant root exudates and breakdown products feed the microbes and the microbe in tum often benefit the plant. Mycorrhizal fungi are important tools for increasing growth, development and yield of economically important plants, they play important role of biofertilizer which can help establish plants in nutrient deficient soils, particularly phosphorus deficient soils, arid, semi-arid and waste lands.

The rhizosphere is a very complex environment in which the effects of the plant on soil microorganisms and the effects of the microorganisms on the plant are interacting and are interdependent. Plant root exudates and breakdownproducts attract microbes and feed them and, in turn, the plants often bene?t from the microbes. Interactions among microorg- ismsandplantrootsareessentialfornutritionalrequirementsoftheplant. Plant growth, development and productivity are largely dependent on the soil environment in the root region rhizosphere. The new techniques of studying the rhizosphere enables us to get a much better understanding of the dynamics of the rhizosphere population, such rhizosphere studies beingofinteresttoagriculturists,soilbiologists,chemists,microbiologists andmolecularbiologists. The rhizosphere microbes in?uence the root environment in several ways. They may change the oxidation-reduction potential, in?uence the availabilityofmoistureandnutrients,producegrowthinhibitingorgrowth promoting substances in the form of exudates, provide competition and possiblyinducemanyothereffects.Mycorrhizalassociationsarebene?cial in mineral uptake and in increasing root surface area for effective ion absorption. Antagonism,competitionandsynergisminsoilandtherhizoplane(r- zosphere) are the most important microbial interactions to consider in the study of rhizosphere biology. With the growing information on the production of growth regulators, competitiveness of the microbes in the rhizosphere, microsymbionts, and other factors, their effect upon plant growth will become more evident. Experiments on the introduction of microbes or their products in the rhizosphere will help to improve our understandingofthebiologyoftherhizosphere.

The rhizosphere is a very complex environment. The interactions among microorganisms and the plant roots are essential for the nutrition, growth and productivity of the plant. On the other hand, the microorganisms also benefit from their interactions with the plant. Rhizosphere studies are of interest to agriculturists, soil biologists, chemists, microbiologists and molecular biologists. Microbial Activity in the Rhizosphere will be useful to the beginner as well as to experienced scientists. It starts with contributions dealing with the basic concepts in rhizosphere biology and the techniques used in these studies. Further topics include the bacterial community composition, rhizosphere of arbuscular mycorrhizal roots, significance of AM fungi in relation to form and functioning of the root system, the role of microsymbionts in plant growth and health, and the impact of rhizosphere environment on pre-infection behaviour of Oomycetous plant pathogens like Aphanomyces, Phytophthora and Pythium.

The importance of mycorrhiza for the improvement of plant growth is increasingly being realised in Agriculture and Forestry and several mycorrhizal fungi have been commercially recognised for the purpose. The aim of this book is to describe the various techniques used to study the mycorrhizal biology. Problems with preparing such a book are many. Mainly mailing of manuscripts to and from authors resulted in irregular and final editing. Every effort was made not to change the peer review original manuscript to ensure accuracy. Our sole aims is to communicate to the greatest extent possible a current world need in mycorrhizal research. Plant productivity is regulated by microbial associations established in the plant root systems. The interactions of microorganisms and plant roots are especially important in providing nutritional requirements of the plant and the associated microorganisms. Plant growth and development are controlled largely by the soil environment in the root region -rhizosphere. This is a very complex environment in which the effects of the plant on soil microorganisms and the effects of microorganisms on the plant are interacting, interdependent and highly complex. Plant root exudates and breakdown products feed the microbes and the microbe in tum often benefit the plant. Mycorrhizal fungi are important tools for increasing growth, development and yield of economically important plants, they play important role of biofertilizer which can help establish plants in nutrient deficient soils, particularly phosphorus deficient soils, arid, semi-arid and waste lands.