G. Bagyanarayana, M.Sc., Ph.D. (Osmania University) is a Professor in Botany Department, Osmania University, and Hyderabad. He has 30 years of teaching and research experience. He has guided Ph.D. students, published more than 80 papers in National and International journals of repute. He is a recipient of Prof. M.J. Narasimhan Award and gold medal by Indian Phytopathological Society. B. Bhadraiah, M.Sc.Ph.D is working as a Professor in Botany Department, Osmania University, and Hyderabad. He has 26 years of teaching and research experience. He is the author of five books and has published more than 28 research papers in national journals. I.K. Kunwar obtained her D.Phil. from Allahabad University, Allahabad and worked as lecturer in Kumaon University, Nainital. She was Visiting Research associate in the University of Illinois, Urbana Champaign, U.S.A. Presently; she is working in the Botany Department of Osmania University, Hyderabad. She has published more than 60 research papers in National and International journals.