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Robert R. Martin

Bob Martin

Professor (Courtesy),
Ph.D., Wisconsin-Madison, 1979.

Research Leader USDA-ARS
 Horticultural Crops Research Unit


Faculty of the Center for Genome Research and Biocomputing

Office/Lab: USDA Horticultural Crops Research Unit
Phone: 541-738-4041/4040

Research Area

Characterization and control of virus diseases of small fruit crops.

Description of Research

The Pacific Northwest is a major producer of small fruit crops, with combined small fruit acreage over 130,000 for the states of Idaho , Oregon and Washington . There are thousands of growers producing small fruit crops, dozens of processing/packing companies, and over 700 wineries in the region. The yield and quality of small fruit crops are adversely affected by viruses that are transmitted by soil-borne and aerial vectors. Some of these viruses can be limiting factors in production when they occur in single infections but mixed infections are more common in production fields and often result in various nondescript "decline" symptoms that can range from minor to 100% crop loss. In addition, there are many uncharacterized diseases of these crops that are caused by "graft transmissible agents" believed to be viruses.  

Since these crops are vegetatively propagated, production of virus-free plants requires effective control strategies during the 2-4 years the plants are propagated for increase in nurseries before they are planted in production fields. Improved virus detection and identification techniques are needed to improve testing for quarantine, certification programs and identification of inoculum sources. Current detection protocols for uncharacterized viruses are time consuming, requiring graft indexing onto several indicators which takes from several months to years to complete.

During the past 5 years we have made an effort to develop diagnostics for viruses known to cause diseases in strawberry, red and black raspberry and blackberry. In the case of strawberry we now have laboratory based tests for 22 of the known viruses reported in strawberry with only strawberry pseudo-mild yellow edge virus and strawberry latent C still lacking sequence information. Our approach has been to purify double stranded RNA from infected plants and use this as starting material for cloning and sequencing. This has been very successful for virus of strawberry and Rubus spp. but we have had very limited success with dsRNA extraction from blueberry and cranberry. With this strategy we have identified and characterized several new viruses in strawberry.

In the case of Rubus species, with collaborators in Arkansas, North Carolina, Germany and Scotland, we have identified four new viruses in blackberry and two each in red and black raspberry and developed RT-PCR tests for each of these viruses. There are several emerging virus diseases of Rubus spp . in the US, including the decline of black raspberry in the Pacific Northwest and Midwest, the decline and death of blackberry in the South and Southeast caused by a virus complex and an increasing problem with crumbly fruit in red raspberry and blackberry in all production areas.

The identification of Strawberry pallidosis associated virus as part of a decline complex in strawberry in California was surprising as this was thought to be a minor virus previously. Recent work in collaboration with colleagues at Salinas, CA, has shown that this virus along with at least two related viruses are transmitted by whiteflies in strawberry and a component of a complex of aphid and whitefly transmitted viruses that caused a severe decline in strawberry in California from 2002 to 2004. A similar decline of strawberry in the Pacific Northwest , which has been a severe problem since 2000 is caused by a complex of four aphid-transmitted viruses. The whitefly transmitted viruses were rarely found in the Pacific Northwest .

Blueberry scorch virus was first found in the Fraser Valley of British Columbia in the summer of 2000 and has since been identified in cranberry . Since then it has been determined that multiple strains of the virus occur in B.C. and the resulting disease is much more severe than in Oregon and Washington . The severe strain(s) of this virus poses a threat to the blueberry industry in the PNW. Understanding the vectors of these severe strains and identification of native vegetation that may serve as hosts are needed to develop an appropriate control strategy, which is especially important in B.C. and northern Washington . Efforts to eradicate this virus from Oregon are underway.

Raspberry bushy dwarf (RBDV) has been a reemerging virus in the Pacific Northwest and wherever Rubus species are grown over the past 15 years. In 1997, RBDV was found for the first time in 'Marion' blackberry in the Pacific Northwest . 'Marion' has been a widely grown cultivar in this area since the early 1960's. The affect of RBDV on 'Marion' is dramatic, drupelet number, fruit size and yield was reduced by 35%, 25% and 40%, respectively, but did not affect cane number or length. The virus also causes a general chlorosis in the leaves of infected plants that is not expressed early in the season, but is very obvious by early July. The incidence of RBDV in 'Marion' blackberry has been increasing and several fields have been removed due to problems with fruit quality. We have developed RBDV resistant 'Meeker' red raspberry through genetic engineering. Of 249 transgenic lines evaluated, 24 lines exhibited some level of resistance. The resistance of the best line has withstood repeated graft inoculation and six years of exposure to extreme disease pressure in a field situation where 202 of 202 wild-type plants were infected after three years.

Work on a serious disease of black raspberry (Rubus occidentalis) in Oregon demonstrated the presence of Black raspberry necrosis virus in declining plants. Plants showing mosaic symptoms declined rapidly and in many cases died over a span of 2-4 years. The virus has two RNAs and is most similar to Strawberry mottle virus . It is transmitted by the large raspberry aphid (Amphorphora agathonica) and the green peach aphid (Myzus persicae). A diagnostic test based on polymerase chain reaction (PCR) was developed and used to identify the virus in transmission studies with the two aphids listed above and in alternate hosts. The virus infects red raspberry, commercial and wild blackberry and surprisingly bracken fern symptomlessly, which causes problems for growers trying to control the virus.

Research Group Members

Graduate Students

Alfredo Diaz Lara

Related Links

USDA Lab Page


Martin, R.R., James, D. and Levesque , C.A. 2000. Impacts of Molecular Diagnostic Technologies on Plant Disease Management. Annu. Rev. Phytopathol. 38:207-239.

Bristow, P.R., Windom, G.E. and Martin, R.R. 2002. Recovery of plants infected with Blueberry shock virus (BlShV). Acta Horticulturae 574:85-89.

Kawchuk, L., Jaag, H.M., Toohey, K., Martin, R., Rohde, W. and Prufer, D. 2002. In planta agroinfection by Canadian and German Potato leafroll virus full-length cDNAs. Can. J. Plant Pathol. 24:329-243.

Strik, B. and Martin, R.R. 2003. Impact of Raspberry bushy dwarf virus on 'Marion' blackberry. Plant Dis. 87:294-296.

Tzanetakis, I.E. and Martin, R.R. 2004. Complete nucleotide sequence of a strawberry isolate of Beet pseudo yellows virus. Virus Genes 28:239-246.

Tzanetakis, I.E., Halgren, A.B., Keller, K.E., Hokanson , S.C. , McCarthy, P.L., Maas , J.L. and Martin, R.R. 2004. Identification and detection of a virus associated with strawberry pallidosis disease. Plant Dis. 88:383-390.

Klesk, K., Qian, M. and Martin, R.R. 2004. Aroma extract dilution analysis of cv. Meeker (Rubus idaeus L.) red raspberry from Oregon and Washington . J. Agric. Food and Chem. 52:5155-5161.

Tzanetakis, I.E., Mackey, I.C. and Martin, R.R. 2004. Strawberry necrotic shock virus is a distinct virus and not a strain of Tobacco streak virus. Arch. Virol. 149:2001-2011.

Martin, R.R. 2004. Recommended procedures for detection of viruses of small fruit crops. Acta Hort. 656:199-207.

Martin, R.R., Jelkmann, W. and Candresse, T. 2004. Guidelines for the development of new methods for virus testing of fruit trees and small fruit crops. Acta Hort. 657:597.

Tzanetakis, I.E., Reed, J. and Martin, R.R. 2005. Nucleotide sequence, genome organization and phylogenetic analysis of Strawberry pallidosis associated virus , a new member of the genus Crinivirus . Arch. Virol. 150:273-286.

Tzanetakis, I.E., Keller, K.E. and Martin, R.R. 2005. The use of reverse transcriptase for efficient first- and second-strand cDNA synthesis from single- and double-stranded RNA templates, J. Virol. Methods 124:73-77.

Tzanetakis, I.E. and Martin, R.R. 2005. New features of the genus Ilarvirus revealed by the nucleotide sequence of Fragaria chiloensis latent virus . Virus Research 112:32-37.

Ellis, M.A., Martin, R.R. and Wright, S.R. 2005. First report of Raspberry Bushy Dwarf Virus in Ohio . Plant Health Progress doi:10.1094/PHP-2005-0510-01-HN.

Martin, R.R., Eastwell, K.C., Wagner, A., Lamprecht, S. and Tzanetakis, I.E. 2005. Survey for viruses of grapevine in Oregon and Washington . Plant Dis. 89:763-766.

Tzanetakis, I.E., Mackey, I.C. and Martin, R.R. 2005. Tulip virus X (TVX) associated with lemon balm ( Melissa officinalis ) variegation . First report of TVX in the United States . Plant Pathology 54:562.

Tzanetakis, I.E., Postman, J.D. and Martin, R.R. 2005. A member of the Closteroviridae from mint with similarities to all three genera of the family. Plant Dis. 89:654-658.  

Tzanetakis, I.E., Postman, J.D. and Martin, R.R. 2006. Mint virus X: a novel potexvirus associated with symptoms in 'Variegata' mint. Arch. Virol. 151:143-153.

Tzanetakis, I.E., Postman, J.D. and Martin, R.R. 2005. Characterization of a novel member of the family Closteroviridae from Mentha spp. Phytopathology 95:1043-1048.

Pinkerton, J.N., Martin, R.R. 2005. Management of Tomato Ringspot Virus in Red Raspberry with Crop Rotation. International Journal of Fruit Science. 5:55-67.

Martin, R.R. and Tzanetakis, I.E. 2006. Characterization, Detection and Management of Strawberry Viruses. Plant Dis. 90:384-396.

Tzanetakis, I.E., Susaimuthu, J., Gergerich, R.C. and Martin, R.R. 2006. Nucleotide sequence of Blackberry yellow vein associated virus, a novel member of the Closteroviridae . Virus Research 116:196-200.

Wegener, L.A., Martin, R.R., Bernardy, M.G., MacDonald, L. and Punja, Z.K. 2006. Epidemiology and strain identification of Blueberry scorch virus on highbush blueberry in British Columbia. Can. J. Plant Pathol. 28:250-262.

Tzanetakis, I.E., Wintermantel, W.M., Cortez, A.A., Barnes, J.E., Barrett, S.M., Bolda, M.P. and Martin, R.R. 2006.  Epidemiology of Strawberry pallidosis associated virus and occurrence of pallidosis disease in North America. Plant Dis. 90:1343-1346.

Tzanetakis, I.E., Postman, J.D. and Martin, R.R. 2006.  Mint virus X: a novel potexvirus associated with symptoms in ‘Variegata’ mint.  Arch. Virol. 151:143-153.

Susaimuthu, J., Tzanetakis, I.E., Gergerich, R.C. and Martin, R.R. 2006.Yellow vein-affected blackberries and the presence of a novel crinivirus.  Plant Pathol. 55:607-613.


Halgren, A., Tzanetakis, I.E. and Martin, R.R. 2007.  Identification, characterization, and detection of Black raspberry necrosis virus. Phytopathology 97:44-50. 

Tzanetakis, I.E., Halgren, A., Mosier, N. and Martin, R.R. 2007.  Identification and characterization of Raspberry mottle virus, a novel member of the Closteroviridae. Virus Res. 127:26-33.

Tzanetakis, I.E., Postman, J.P. and Martin, R.R. 2007. Identification, detection and transmission of a new Vitivirus from Mentha.  Arch.Virol 152:2027-2033.

Susaimuthu, J., Tzanetakis, I.E., Gergerich, R.C., Kim, K.S. and Martin, R.R. 2008.  Synergistic viral interactions lead to decline of blackberry plants.  Plant Dis. 92:1288-1292.

Pinkerton, J.N., Kraus, J., Martin, R.R. and Schreiner, R.P.  2008.  Epidemiology of Xiphinema americanum and Tomato ringspot virus on red raspberry, Rubus ideaus.  Plant Dis. 92:364-371.

Tzanetakis, I.E., and Martin, R.R., 2008.  A new method for extraction of double-stranded RNA from plants. J. Virol. Methods 149:167-170.

Malowicki, S.M.M., Martin, R.R. and Qian, M.C. 2008.  Comparison of sugar, acids, and volatile composition in raspberry bushy dwarf virus-resistant transgenic raspberries and the wild type ‘Meeker’ (Rubus idaeus L.). J.Agric Food Chemistry 56:6648-6655.

Lee, J. and Martin, R.R. 2009. Influence of Grapevine leafroll associated viruses (GLRaV-2 and -3) on the fruit composition of Oregon Vitis vinifera L. cv. Pinot noir: Phenolics. Food Chem. 112:889-896.

Martin, R.R., Pinkerton, J.N. and Kraus, J. 2009.  The use of collagenase to improve the detection of plant viruses in vector nematodes by RT-PCR.  J. Virol. Methods 155:91-95.

Sabanadzovic, S., Vlaverde, R.A., Brown, J.K., Martin, R.R. and Tzanetakis, I.E.  2009. Southern tomato virus: The link between the families Totiviridae and Partitiviridae.  Virus Res. 140:130-137.

Mekuria, T., Gutha, L.R., Martin, R.R. and Naidu, R.A.  2009.  Genome diversity and intra- and inter-species recombination events in Grapevine fanleaf virus.  Phytopathology 99:1394-1402.

Tzanetakis, I.E., Martin, R.R. and Scott, S.W. 2010.  Genomic sequences of blackberry chlorotic ringspot virus and strawberry necrotic shock virus and the phylogeny of viruses in subgroup 1 of the genus Ilarvirus.  Arch. Virol. 155:557-561.

Kraus, J., Cleveland, S., Putnam, M.L, Keller, K.E., Martin, R.R. and Tzanetkais, I.E.  2010.   A new potyvirus sp. infects Verbena exhibiting leaf mottle symptoms. Plant Dis. 94:1132-1136. 

Fuchs, M., Abawi, G.S., Marsella-Herrick, P., Cox, R., Cox, K.D., Carroll, J.E., Martin, R.R.  2010. Occurrence of Tomato ringspot virus and Tobacco ringspot virus in highbush blueberry in New York State.  J. Plant Pathol. 92:451-459. 

Martin, R.R., Zhou, J. and Tzanetakis, I.E. 2011.  Blueberry latent virus: An amalgam of Partitiviridae and Totiviridae. Virus Research 155:175-180.

Finn, C.E., Strik, B.C., Yorgey, B.M. and Martin, R.R. 2011.  ‘Onyx’ Trailing blackberry. HortScience 46:657-659.

Quito-Avila, D.F., Jelkmann, W., Tzanetakis, I.E., Keller, K.E. and Martin, R.R. 2011.  Complete sequence and genetic characterization of Raspberry latent virus, a novel member of the family Reoviridae.  Virus Res. 155:397-405.

Tzanetakis, I.E., Quito-Avila, D.F. and Martin, R.R. 2011.  Two new virus diseases in Rubus:” Blackberry yellow vein and raspberry crumbly fruit.  Small Fruit News 11:4-7.

Quito-Avila, D.F. and Martin, R.R. 2012. "Real-time RT-PCR for detection of Raspberry bushy dwarf virus, Raspberry leaf mottle virus and characterizing synergistic interactions in mixed infections.  J. Virol. Methods 179:38-44.

Martelli, G.P., Agranovsky, A.A., Bar-Joseph, M., Boscia, D., Candresse, T., Coutts, R.H.A.,  Dolja, V.V., Hu, J.S., Jelkmann, W., Karasev, A.V., Martin, R.R., Minafra, A., Namba, S. and Vetten, H.J.  2011.  Closteroviridae, pp. 987-1011 In: Virus Taxonomy 

Finn, C.E., Kempler, C., Moore, P.P., Strik, B.C., Yorgey, B.M., Martin, R.R. and Galletta, G.J. 2011.  ‘Sweet Bliss’ Strawberry. HortScience 46:1701-1705.

Quito-Avila, D.F., Lightle, D., Lee, J. and Martin, R.R. 2012. Transmission biology of Raspberry latent virus, the first aphid-borne Reovirus.  Phytopathology 102:547-553.