Book excerpt: This volume is envisioned as a resource for researchers working with beneficial and harmful groups of bacteria associated with crop plants. The book is divided into two parts, with Part I on beneficial bacteria including chapters on symbiotic nitrogen fixers and rhizosphere bacteria. The second part consists of detailed descriptions of 8 genera of plant pathogenic bacteria, including Agrobacterium and Herbaspirillum. Each chapter covers terminology, molecular phylogeny and more. soft-rot, Pseudomonas, Xanthomonas, Ralstonia, Burkholderia and Acidovorax There is an opening chapter on the plant-associated bacteria survey, molecular phylogeny, genomics and recent advances. And each chapter includes terminology/definitions, molecular phylogeny, methods that can be used (both traditional and latest molecular tools) and applications