Plant Pest Diagnostics Center
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Dr. Cheryl BlomquistSenior Plant Pathologist - Specialist Plant Pest Diagnostics Branch, California Department of Food & Agriculture
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Curriculum vitae
Education
- Doctor of Philosophy (Plant Pathology) - University of California, Davis. 2000.
- Bachelor of Science (Biochemistry) - Washington State University, Pullman. 1981
Positions held
2004-present Senior Plant Pathologist (Diagnostician), CDFA-PPD
2001-2004 Associate Plant Pathologist (Diagnostician), CDFA-PPD
Responsibilities:
- Diagnose Phytophthora ramorum the causal agent of Sudden Oak Death for California’s fourteen infested counties.
- Diagnose this disease and other diseases caused by Phytophthoras using symptomatic, morphological and molecular criteria and techniques.
- Adapted an existing set of PCR primers for the diagnosis of P. ramorum. Screen more than 25,000 samples from nurseries and woodlands per year for the presence of this disease.
- Diagnose diseases caused by Phytophthoras in samples submitted to the clinic.
- Diagnose other diseases caused by fungi in woody plants and agricultural crops.
- Give educational talks and training sessions to county biologists, foresters, nursery professionals and park workers about Sudden Oak Death.
2000- 2001 Visiting Posdoctoral Scientist, Department of Plant Pathology, University of California, Davis. (Dr. Lynn Epstein, advisor)
Research project:
- Study of the biology of Eutypa lata, pathogen of mature grapevines.
- Use AFLP to genetically fingerprint isolates from infected mother plants from the
Department of Viticulture and Enology to determine if Eutypa can be vegetatively
transmitted. - Isolated Eutypa from naturally-infected grapevines, identified Eutypa
isolates using mophological criteria and Eutypa-specific PCR. - Perform mating experiments using Eutypa isolates obtained from single ascospores from individual perithecia.
- Performing experiments to determine if conidia produced by Eutypa actually serve as spermatia.
Other duties:
- Support other laboratory projects by designing PCR primers and troubleshooting other lab member's experimental results.
1993-2000 Graduate research assistant, Department of Plant Pathology, University of California, Davis. (Dr. Bruce Kirkpatrick, major professor)
Ph.D.dissertation title:
- “Analysis of Phytoplasma-Infected Insect Vectors in Peach and Pear Orchards in California and Identification and Characterization of an Immunodominant Protein Gene from the Western X Disease Phytoplasma”
Field Research:
- Collected and analyzed pear psylla monthly from 3 orchards in northern California to determine whether the number of psylla infected with the pear decline phytoplasma varied seasonally.
- Compared the numbers of pear psylla detected by PCR versus those detected with hybridiation analysis.
- Performed a study to evaluate the peach yellow leaf roll vector populations and to assess the control of peach yellow leaf roll in 3 Yuba county orchards using an insecticide treatment and a zinc defoliation treatment.
- Evaluated the zinc treatment in preliminary experiments on healthy peach trees to see if the treatment affected bloom number, fruit size or yield.
Laboratory Research:
- Cloned and sequenced an immunodominant protein gene from the Western X-disease phytoplasma using degenerate primers obtained from tryptic peptides derived from the purified protein.
- Expressed the protein in E. coli, purified the expressed protein and showed that antibodies made to the expressed protein react with the native protein in the Western X phytoplasma.
Professional:
- Presented research results at meetings of the American Phytopathological Society, the International Organization of Mycoplasmology, UC Davis' Plant Pathology's departmental seminar and laboratory meetings.
Other Duties:
- Analyzed samples submitted by farm advisors and CDFA for phytoplasmas and reported results.
Techniques routinely performed:
- PCR, both routine assays and primer design
- DNA hybridization assays using radioisotopes
- agarose gel electrophoresis
- DNA extraction techniques from both insects and plants
- DNA quantitation using the Hoechst dye binding assay
- protein purification
- SDS PAGE
- immunoaffinity chromatography
- antibody purification
- Fab fragment production
- cloning
- Southern blot analysis
- ELISA
- dot blot analysis (both protein and DNA).
Greenhouse and insectary:
- Maintained both leafhopper and pear psylla colonies.
- Perform transmission experiments with both leafhoppers and psylla.
- Stratify, plant and maintain pear seedlings and pear trees.
- Plant and maintain celery for Colladonus montanus rearing.
- Maintain cultures of phytoplasma strains in Catharanthus roseum by grafting.
- Perform routine propagation of C. roseum by rooting cuttings.
1989-1993 Staff Research Associate, Athena Neurosciences, South San Francisco, CA (Dr. Dale Schenk, supervisor)
Technical:
- Characterize and evaluate monoclonal and polyclonal antibodies made in house using RIA, ELISA, immunoblot and immunoprecipitation techniques.
- Designed and coordinated the purification of antibodies from ascites to extremely low pyrogen standards using FPLC and open column chromatography.
- Developed ELISA’s for the measurement of Botulinum toxin, antibodies to Botulinum toxin serotype A and B, and alpha-1 antichymotrypsin.
Awards, Offices held, Professional Memberships
- Jastro Shields Grant 1997-1998
- Dow Ellanco Student Award 1998
- American Phytopathological Society membership
- International Organization of Mycoplasmology membership
- Department of Plant Pathology Students President, 1994-1995
- Student-run Plant Disease Clinic Chair 1996-1997
Publications and Abstracts
- Donahoo, R.S., Moulton, J.K., Blomquist, C.L., Thomas, S.L., Cooke D.E.L. and Lamour, K.H. 2006. Phytophthora foliorum sp. nov., a new species causing leaf blight of azalea. Mycological Research 110:1309-1322.
- Hostert, N.D., Thomas, S.L., Fogel, D.L, Blomquist, C.L. and Davis R.M. 2006. First report of Ramularia carthami, causal agent of Ramularia leaf spot of Safflower in California. Plant Disease 90:1260.
- Tjosvold, S.A. Chambers, D.L., Thomas, S.L. and Blomquist, C.L. August 25, 2005. First report of Phytopththora ramorum infecting Camellia flower buds in North America. Online. Plant Health Progress doi: 10.1094/PHP-2006-0825-01-BR.
- Tjosvold, S.A., Buermeyer K.R., Blomquist, C.and Frankel S. 2005. Nursery Guide for Diseases of Phytophthora ramorum on Ornamentals: Diagnosis and Management. Division of Agricultural and Natural Sciences Publications. Publication #8156
- Blomquist, C., Irving, T., Osterbauer, N., Reeser, P. July 28, 2005. Phytophthora hibernalis: a new pathogen of Rhododendron and evidence of cross amplification with two PCR detection assays for Phytophthora ramorum. Online. Plant Health Progress doi: 10.1094/PHP-2005-0728-01-HN.
- Martin, F. N., Tooley, P.W. and Blomquist, C.L. 2004. Molecular detection of Phytophthora ramorum the causal agent of Sudden Oak Death in California and two additional species commonly recovered from diseased material. Phytopathology 94:621-631.
- Blomquist, C.L. Kubisiak, T. 2003. Laboratory diagnosis of Phytophthora ramorum from field samples. Sudden Oak Death Online Symposium April 21-May 12, 2003 http://www.apsnet.org/online/proceedings/SOD/.
- Blomquist C.L., Fischer, K. and Fry, M. 2002. Can vertebrates transmit viable Phytophthora ramorum spores—data from the lab. Abstract for the Sudden Oak Death Science Symposium Dec. 15-18, Monterey, California.
- Blomquist, C. L. and Kirkpatrick B. C., 2002. Frequency and seasonal distribution of pear psylla infected with the pear decline phytoplasma in California pear orchards. Phytopathology 92: 1218-1226.
- Blomquist, C.L. and Kirkpatrick, B.C., 2002. Identification of phytoplasma taxa and insect vectors of peach yellow leaf roll disease in California. Plant Disease: 86:759-763.
- Blomquist, C.L. Aster yellows and Beet Leafhopper-Transmitted Virescence Agent Yellows in Compendium of Umbelliferous Crop Diseases, R.M. Davis, editor, 2002.
- Blomquist, C.L. and Kirkpatrick, B.C., 2001. An immunodominant membrane protein gene from the X-disease phytoplasma is distinct from those of other phytoplasmas. Microbiology 147:571-580.
- Blomquist, C.L. and Kirkpatrick, B.C., 1998. Infectivity of phytoplasma insect vectors collected in pear decline and peach yellow leaf roll-infected orchards in northern California. Abstract for the IOM meetings, Sydney, Australia, July 1998.
- Blomquist, C.L. and Kirkpatrick, B.C., 1997. Infectivity of pear psylla (Cacopsylla pyricola Foerster) collected from pear decline infected trees. Phytopathology 87:S9.
- Smart, C.D., Schneider, B., Blomquist, C. L., Guerra, L.J., Harrison, N. A., Ahrens, U., Lorenz, K-H, Seemuller, E., Kirkpatrick, B. C., 1996. Identification of phytoplasma-specific PCR primers obtained from the 16S/23S rRNA spacer region. Applied and Environmental Microbiology 62: 2988-2993.



