The scope of microbiology has enlarged tremendously during last 25-30 years. The present volume deals about the microbial diversity comprising 25 reviews papers and research papers from outstanding scientists of India. This will provide a new sight in basic and applied research related to plants and microbial diversity. It mainly includes, fungal, bacterial and nematode diversity, mushrooms cultivation, biofertilizers, disease resistance, biological control, plant disease management, plant diseases and role of microbes in soil fertility. The primary goal of preparing this Volume is to present a balanced view of the diversity and provide the fundamental information that will allow students and scientists to understand the complexities of those issue. This book is suitable for students of post-graduate, research scholars, senior research fellow and research associate in mycology, microbiology, plant pathology, plant bacteriology and plant protection. It will also be extremely useful to the teachers, instructors and scientists engaged in pursuit highger knowledge in this area.'