Dr. Krishna V. Subbarao
Krishna V. Subbarao was born in 1958 in India. B.Sc. and M.Sc. in plant pathology from the University of Mysore, India, and Ph.D. in Plant Pathology from Louisiana State University (LSU). Subbarao joined the faculty of Department of Plant Pathology at the California-Davis, where he is currently a full professor. His research focuses on the etiology, epidemiology, and impact of altered production practices on pathogen ecology and on elucidating mechanisms of disease suppression attained via cultural manipulations. He previously served as Associate Editor and Senior Editor of Phytopathology and has served either as a member or chair of a number of APS committees. Subbarao’s impressive career achievements have come through the study of two fungal pathogens, Sclerotinia spp. and Verticillium spp. He has utilized these systems to develop pioneering research programs in the assessment of changing production practices on plant diseases.
Subbarao’s early career demonstrations like benefits of deep-plowing to bury pathogen propagules were the best-documented examples linking effects of farming practices to develop effective disease management strategies. In a series of articles, he developed a highly innovative, yet very practical knowledge base of soilborne disease management protocols. Framework developed by Dr. Subbarao has become the standard approach for managing diseases caused by the Sclerotinia species.
Subbarao's widely acclaimed contributions also comes from his studies concerning the ecology of Sclerotinia. His group demonstrated how differential survival in soil, environmental requirements for spore production, and cultural practices help explain the prevalence of S. sclerotiorum in the San Joaquin Valley and its rarity in the Salinas Valley, while the reverse pattern holds for S. minor. To break the lettuce mosaic virus vector life cycle, lettuce-free period are mandatorily imposed during the rainy season in the Salinas Valley, fastidious soil moisture conditions which were generated also supported apothecial production by S. sclerotiorum. Lettuce free period therefore helped to surpass the infections from both the diseases. This is a rare example of legislative action to control one disease having the inadvertent beneficial effect of suppressing another threatening disease. His group provided new insights into the reproductive biology of S. sclerotium.
One more area of significant and ongoing accomplishment is the study of Verticillium wilt caused by Verticillium dahliae. Subbarao's research on V. dahliae has offered insights into both pathogen biology and sound information germane to disease management. Using a strain that had been transformed to express a fluorescent protein, subbarao demonstrated and compared the differential development of the pathogen in susceptible and resistant lettuce cultivars (resistant cultivar sustained feeder root infections, the host prevented pathogen entry into the tap root and the stem). Subbarao was also instrumental in a multi-institutional effort to sequence the genomes of V. dahliae and two other species of Verticillium that were released recently.
Subbarao's contributions have also come from his stellar work on developing rotation strategies for pathogens possessing broad host ranges. In a series of well-conceived studies, he determined that broccoli cultivation not only reduced resident soil propagules of fungi, but also wilt incidence and severity in subsequent susceptible crops. He demonstrated that not all glucosinolates and their catabolic products are involved in pathogen suppression, and that V. dahliae suppression by broccoli involves multiple factors (e.g., the type of glucosinolates and their catabolic products, soil microbial communities).
He has received various awards since his plant pathology career began more than 25 years ago, including the C.W. Edgerton Honor Award for outstanding performance as a graduate student, the Syngenta Award, the Professor M.J. Narasimhan Medal from the Indian Phytopathological Society, and an APS Fellow award. Subbarao has been very active in the publishing world. He is credited with writing for contributing to more than 150 research papers in refereed journals, 15 book chapters, 20 extension bulletins, 15 proceedings, and 254 extension reports. He has also served as editor of the Compendium of Lettuce Diseases, as well as associate editor and then senior editor on the Phytopathology Editorial Board for a total of seven years. He has also overseen the research of staff, undergraduates, graduate students working toward their Ph.D. degrees, and 15 post-docs from diverse cultural backgrounds. He is quiet but intensely deliberative and is imbued with the finest human qualities.