Dr. Ken Eastwell
Research Highlight
Virology Program in Perennial Crops
Over 200 diseases of stone and pome fruit trees are caused by virus or virus-like agents (hereafter referred to as viruses). Unlike other classes of plant pathogens, once viruses are introduced into trees of an orchard, the only practical options are to remove the diseased trees or to live with the consequences of those infections. Both options reduce farm income by either limiting or eliminating production and threatening the economic viability of U.S. fruit operations (see PDF file). These effects in the orchard are insidious and often unnoticed, but the recurrent losses caused by virus infection of perennial crops are very significant.
This research program develops a basic understanding of graft-transmissible diseases that affect perennial crops including temperate fruit trees, hop plants, grapevines and some ornamentals. This information is applied to minimize the economic impact of diseases by:
- identifying pathogens that yield diseases of specialty crops
- developing rapid diagnostic methods appropriate for disease management. In addition to the development of molecular assays, a major component of the program is the development of monoclonal antibodies for serological detection of viruses.
- determining the major routes of infection (e.g. insect vectors, pollen transmission)
- developing horticultural practices that aid in limiting disease spread
In the 1950's, graft-transmissible agents caused significant economic impact to temperate tree fruit production in the United States. Indeed, diseases caused by graft-transmissible agents were a major constraint to deciduous fruit production in every region of the country. Many of these agents were distributed through the use of infected nursery stock. To minimize the spread through the industry and to reverse the trend of increasing disease incidence, fruit-growing States began developing certification programs to provide reliable disease-free propagation material to nurseries that could then safely produce larger quantities of trees for growers. In 1955, a cooperative agreement created a program that eventually became the National Research Support Project 5: National program for controlling virus diseases of temperate fruit tree crops (NRSP-005). This consolidated financial and experienced personnel resources in a program to provide these services nationally. Since 1988, it has also acquired new clones from foreign sources under the terms of a “Departmental permit” issued by United State Department of Agriculture Animal and Plant Health Inspection Service for the importation of fruit and nut trees. Since the permit was obtained in 1988, the role of NRSP-005 as an importation site has grown steadily. The program currently tests than 60 cultivars annually. Almost all of this work is performed under contract with external agencies.
Recent publications and presentations present the flavor of the research conducted in this program:
- A novel virus was detected and characterized in ornamental Hellebores (Christmas rose and Lenten rose). This led to the development of a diagnostic test for this disfiguring disease. (see PDF file)
- Ilarviruses that infect hop plants were characterized based on their reactions in a panel of serological tests and on the sequence of the coat protein genes. (see PDF file)
- A biocontrol agent with the potential to control the bacteria causing crown gall disease of grape vines was identified and characterized. (see PDF file)
- A novel approach to calculate the economic losses incurred by fruit tree viruses to the U.S. economy was used and revealed that the losses are substantial. (see PDF file)
- Cydia pomonella granulosis virus is a potential biocontrol agent for controlling codling moth, but it is also poses a serious problem for large insect colonies such as those required for sterile insect release programs. Research identified new sources of contamination in such facilities. (see PDF file)
This program requires the cooperation of many talented people:
- Bill Howell oversees the tree fruit quarantine program (NRSP-005)
- Jan Burgess, Marion Gomez, Kris Keel, Elmer Wilcowski and ‘Junior’ Meza perform many duties in the fruit tree virus program including field indexing and heat therapy for virus and viroid elimination (NRSP-005)
- Lorraine Seymour provides research and molecular diagnostics for many aspects of the research program and to support NRSP-005
- Keri Druffel provides valuable assistance with many molecular aspects of the program
- Carol McKinney oversees the WSU ELISA Service Center that provides serological assays to support research programs, and certification programs for fruit trees and seed production
- Tina Vasile performs the meristem culture of hop plants to produce virus-free plantlets that become the basis of the hop rootstock certification program
- Susan Lambert maintains the collection of research plants and assists with field and greenhouse operations
- Graduate students Hui Hou, Amogelang Segwagwe and Dan Villamor keep the laboratory active and contribute significantly to our research efforts
Updated 2006
Click on photos to enlarge
Heading using the h3 tag
Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.