2011 Annual Report
Substantial results were realized over the 4 years of the project. The Pacific Northwest region of the United States is a leading producer and exporter of berry crops, grapes and wine. Combined, these crops are subject to more than 100 different viruses that occur worldwide. Many of these viruses cause economic damage in single infections or mixed virus infections, resulting in constraints for production and export. Over the course of the project, we have significantly improved our understanding of the importance of virus complexes in causing diseases in these crops. We have shifted the paradigm from disease is caused by a pathogen to virus diseases of woody perennials are often caused by virus complexes. In the study of these virus complexes, we have characterized new viruses that infect, blackberry (14), blueberry (3), raspberry (4) and strawberry (4). Diagnostic assays have been developed for these 25 viruses and are being used in quarantine and certification programs as well as in epidemiological research. An outcome of the research on strawberry virus complexes and the epidemiology of the viruses has led to modification in control measures that resulted in the use of fewer pesticides and effective control of a virus complex that was causing at least $25 million in losses per year. In raspberry, the work has led to an understanding of the importance of virus complexes in causing crumbly fruit. This work has opened the possibility of alternative control measures for control of this disease since we now know that some of the viruses are vectored by aphids, where previously it was thought that the causal virus was pollen transmitted. Since this is the only laboratory that focuses on viruses in berry crops, we are involved with research throughout the United States. For example, identification of new viruses in blackberry and blueberry in the southeastern U.S. and MI was done in collaboration with colleagues in those regions. The virus characterization is usually done in our laboratory and transmission studies in the region where the disease occurs. The emphasis on virus complexes is to identify the critical viruses necessary to cause disease and their vectors. In developing management strategies, efforts are targeted toward controlling one of these critical viruses, which controls the disease even though all the viruses are not controlled. Additionally, we have worked with plant breeders in the United States to “clean up” new small fruit cultivars of viruses before they are released to the industry; this has led to improved quality of the plant material that is available to growers. The overall impact of these accomplishments is that producers have new information on pest management decisions, better quality planting stocks, and more effective and environmentally friendly management tools to control virus diseases of the berry crops.
Fuchs, M., Abawi, G.S., Marsella-Herrrick, P., Cox, R., Cox, K.D., Carrol, J.E., Martin, R.R. 2010. Tomato ringspot virus and tobacco ringspot virus in highbush blueberry in New York State. Journal of Plant Pathology. 92:451-459.
Martin, R.R., Zhou, J., Tzanetakis, I.E. 2011. Blueberry latent virus: An amalgam of the Totiviridae and Partitiviridae. Virus Research. 155:175-180..
Kraus, J., Cleveland, S., Tzanetakis, I.E., Keller, K.E., Putnam, M., Martin, R.R. 2010. A new Potyvirus sp. infects Verbena exhibiting leaf mottling symptoms. Plant Disease. 94:1132-1136.
Quito, D.F., Jelkmann, W., Tzanetakis, I.E., Keller, K.E., Martin, R.R. 2011. Complete sequence and genetic characterization of Raspberry latent virus, a novel member of the family Reoviridae. Virus Research. 155:397-405..
Hadidi, A.F., Olmos, A., Pasquini, G., Barba, M., Martin, R.R., Shamloul, A. 2011. Double-stranded RNAs and their use for characterization of recalcitrant viruses. In: Hadidi, A., Barba, M., Candresse, T., and Jelkmann, W., editors. Virus and Viruslike Diseases of Pome and Stone Fruit. St. Paul, MN, APS Press. 323-326.
Hadidi, A.F., Olmos, A., Pasquini, G., Barba, M., Martin, R.R., Shamloul, A. 2011. Polymerase chain reaction for detection of systemic plant pathogens. In: Hadidi, A., Barba, M., Candresse, T., and Jelkmann, W., editors. Virus and Viruslike Diseases of Pome and Stone Fruit. St. Paul, MN, APS Press. 341-359.