Author: Neelawan Pongsilp

Phenotypic and Genotypic Diversity of Rhizobia

eBook: US $32 Special Offer (PDF + Printed Copy): US $144
Printed Copy: US $128
Library License: US $128
ISBN: 978-1-60805-552-4 (Print)
ISBN: 978-1-60805-461-9 (Online)
Year of Publication: 2012
DOI: 10.2174/97816080546191120101


Rhizobia are composed of specific groups of bacteria that have the ability to induce symbiotic nitrogen-fixing nodules on the roots or stems of leguminous plants. Rhizobia have attracted a great attention for more than 4 decades because of their enormous agricultural and economic value in sustainable agriculture. Up to the present time, many legumes have been found to be nodulated by several rhizobial species in diverse taxonomic groups. An assessment of rhizobial diversity provides pivotal information in understanding the horizontal gene transfer among bacterial genera and species, the bacterial evolution and the symbiotic effectiveness. The classification of rhizobia is becoming increasingly complex and is revised periodically because of new findings that propose new genera and new species. Phenotypic and Genotypic Diversity of Rhizobia presents the application of conventional and molecular analyses, including numerical analysis, enzyme patterns, serological studies, plasmid profile, polymerase chain reaction (PCR)-fingerprinting, amplified fragment length polymorphism (AFLP), restriction fragment length polymorphism (RFLP), PCR-RFLP and sequence-based methods, to the examination of rhizobial diversity. Principles of these techniques, the resolving power, the advantage and the limitation of these techniques are evaluated. Current taxonomy of rhizobia classifies them into 17 genera and 118 species. The book explains background knowledge about rhizobia and follows this up with a broad perspective on rhizobial diversity, information on characteristics specific to each group of rhizobia, the relationship among rhizobial groups as well as genetic factors contributed to rhizobial diversity. Contemporary methods for examination of rhizobial diversity are also suggested and discussed. Readers of this e-book will find updated information on key concepts in classification and taxonomy of rhizobia, the categories and techniques used to examine the phenotypic and genotypic diversity of rhizobia (including numerical analysis, enzyme patterns, serological study, plasmid profile, polymerase chain reaction (PCR)-fingerprinting, amplified fragment length polymorphism (AFLP), restriction fragment length polymorphism (RFLP), PCR-RFLP and sequence analysis).

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It is such an honor and I have a great pleasure to write a foreword for this special book, “PHENOTYPIC AND GENOTYPIC DIVERSITY OF RHIZOBIA”, written by Dr. Neelawan Pongsilp.

Rhizobia are defined as bacteria that induce nitrogen-fixing nodules on roots and stems of legumes. Members of rhizobia have expanded from the only one genus, Rhizobium, in the early 80’s to 17 genera identified up to date. The classification and taxonomy of rhizobia have been revised periodically. Many rhizobial strains have been moved into the other genera and species. Novel genera and species of rhizobia in the alpha (?), beta (?) and gamma (?) subclasses of Proteobacteria have been proposed as well. The diversity of rhizobia has been assessed based on phenotypic and genotypic characteristics. The genetic relationships among rhizobial populations are of interest because they can provide the information on the gene transfer and the adaptation of bacteria to environments. Despite increasing studies on rhizobial diversity and their importance in sustainable agriculture world-wide, the gathering information is quite rare.

This book provides valuable information. It covers the main concepts in classification and taxonomy of rhizobia. It brings the categories and techniques used to examine the phenotypic and genotypic diversity of rhizobia, from principle to application for rhizobial members. The techniques described in the book include numerical analysis, enzyme pattern, serological study, plasmid profile, PCR fingerprinting, PCR-RFLP, RFLP, IS fingerprint and sequence analysis. The discriminating power and limitations of these techniques are discussed and compared. The plant-growth promoting abilities of rhizobia are also provided. In this book, the information is gathered to well-organized and easily comparable formats. It rises up the new aspects on the symbiotic promiscuity and genetic relatedness of rhizobia.

The author, Dr. Neelawan Pongsilp, has a vast experience in bacterial diversity and community, especially rhizobia. Her research articles published in the peer-reviewed journals prove her well qualified for writing on this topic. She pushes the Rhizobia world forward with her slender frame. For years, I’ve admired her devotion to researches and got inspired by her hard work, professional skills and opinions. As I know that she’s made an excellent effort in writing this book, she achieves a good progress in providing a useful resource of knowledge. This book will benefit the readers in microbiological and molecular biological fields.

Pongrawee Nimnoi, Ph.D.
Department of Microbiology
Faculty of Liberal Arts and Sciences
Kasetsart University
Nakhon Pathom