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 Crops Pathology and Genetics Research: Davis, CA
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Daniel  Kluepfel    Research Leader **Phone:**
(530) 752-1137**Fax:**
(530) 754-7195**Office:**
University of California, Davis
284 Hutchison Hall
Davis, CA 95616
 /ARSUserFiles/34929/DKK.jpg
 Publications(Clicking on the reprint iconReprint Icon  will take you to the publication reprint.)Evaluating new breeding material for salinity tolerance in almond rootstocks and exploring novel sources of salinity tolerance in Prunus-(Abstract Only)Structural and functional leaf diversity lead to variability in photosynthetic capacity across a range of Juglans regia genotypes-(Peer Reviewed Journal) Momayyezi, M., Rippner, D.A., Duong, F.V., Raja, P.V., Brown, P.J., Kluepfel, D.A., Earles, J., Forrestel, E.J., Gilbert, M.E., McElrone, A.J. 2022. Structural and functional leaf diversity lead to variability in photosynthetic capacity across a range of Juglans regia genotypes. Plant Cell and Environment. 45(8):2351-2365. https://doi.org/10.1111/pce.14370.The U.S. National Plant Germplasm System...Preserves Genetic Diversity for All People for All Time-(Trade Journal) Kinard, G.R., Bassil, N.V., Hummer, K.E., Reinhold, L.A., Aradhya, M.K., Smith, J.L., Kluepfel, D.A., Galarneau, E.R., Gutierrez, B.L. 2022. The U.S. National Plant Germplasm System...Preserves Genetic Diversity for All People for All Time. Fruit Gardener. March and April 2022/page 12-15.Dessication of the leaf mesophyll and its implications for C02 diffusion and light processing-(Peer Reviewed Journal) Momayyezi, M., Borsuk, A., Brodersen, C., Gilbert, M., Theroux-Rancourt, G., Kluepfel, D.A., McElrone, A.J. 2022. Dessication of the leaf mesophyll and its implications for C02 diffusion and light processing. Plant, Cell & Environment. 45(5):1362-1381. https://doi.org/10.1111/pce.14287.An in vitro bioassay for evaluating the virulence of Pseudomonas savastonoi pv savastanoi isolates on olive-(Peer Reviewed Journal) Salman, M., McClean, A.E., Kluepfel, D.A. 2022. An in vitro bioassay for evaluating the virulence of Pseudomonas savastonoi pv savastanoi isolates on olive. Australasian Plant Disease Notes. 17:1. https://doi.org/10.1007/s13314-022-00448-0.Co-located quantitative trait loci for resistance to Agrobacterium tumefaciens, Phytophthora cinnamomi, and P. pini in Juglans microcarpa × J. regia hybrid rootstock-(Peer Reviewed Journal) Ramasamy, R.K., Luo, M., Leslie, C.A., Velasco, D.M., Ott, N.J., McClean, A.E., Dandekar, A.M., Aradhya, M.K., Brown, P.J., Browne, G.T., Kluepfel, D.A., Westphal, A., Dvorak, J. 2021. Co-located quantitative trait loci for resistance to Agrobacterium tumefaciens, Phytophthora cinnamomi, and P. pini in Juglans microcarpa × J. regia hybrid rootstock. Horticulture Research. 8. Article 111. https://doi.org/10.1038/s41438-021-00546-7.Predicting stomatal closure and turgor loss in woody plants using predawn and midday water potential-(Peer Reviewed Journal) Knipfer, T., Bambach, N., Hernandez, M.I., Bartlett, M.K., Sinclair, G., Duong, F., Kluepfel, D.A., McElrone, A.J. 2020. Predicting stomatal closure and turgor loss in woody plants using predawn and midday water potential. Plant Physiology. 184(2):881-894. https://doi.org/10.1104/pp.20.00500.Field evaluation of olive (Olea europaea) genotypes for resistance to Pseudomonas savastanoi pv savastanoi-(Peer Reviewed Journal) Salman, M., Kluepfel, D.A., Greenhut, R., Preece, J.E., Ferguson, L. 2020. Field evaluation of olive (Olea europaea) genotypes for resistance to Pseudomonas savastanoi pv savastanoi. Journal of Plant Pathology. 102:663-670. https://doi.org/10.1007/s42161-020-00549-8.A comparative study on physiological responses to drought in walnut genotypes (RX1, Vlach, VX211) commercially available as rootstocks-(Peer Reviewed Journal) Knipfer, T., Grom, J., Reyes, C., Momayyezi, M., McElrone, A.J., Kluepfel, D.A. 2020. A comparative study on physiological responses to drought in walnut genotypes (RX1, Vlach, VX211) commercially available as rootstocks. Trees. 34(3):665-678. https://doi.org/10.1007/s00468-019-01947-x.Temporal responses of microbial communities to anaerobic soil disinfestation-(Peer Reviewed Journal) Poret-Peterson, A.T., Sayed	, N., Glyzewski, N., Forbes, H., Gonzalez-Orta, E., Kluepfel, D.A. 2019. Temporal responses of microbial communities to anaerobic soil disinfestation. Microbial Ecology. 80:191-201. https://doi.org/10.1007/s00248-019-01477-6.Sequencing a Juglans regia × J. microcarpa hybrid yields high-quality genome assemblies of parental species-(Peer Reviewed Journal) Zhu, T., Wang, L., You, F.M., Rodriguez, J., Deal, K., Chen, L., Li, J., Chakraborty, S., Balan, B., Jiang, C., Browne, P.J., Leslie, C., Aradhya, M.K., Dandekar, A., McGuire, P.E., Kluepfel, D.A., Dvorak, J., Ming-Chen, L. 2019. Sequencing a Juglans regia × J. microcarpa hybrid yields high-quality genome assemblies of parental species. Horticulture Research. 6:55. https://doi.org/10.1038/s41438-019-0139-1.Sequencing a Juglans regia × J. microcarpa hybrid yields high-quality genome assemblies of parental species-(Peer Reviewed Journal) Zhu, T.,  Wang, L., You, F.M., Rodriguez, J.C., Deal, K.R., Chen, L., Li, J., Chakraborty, S., Balan, B., Jiang, C., Brown, P.J., Leslie, C.A., Aradhya, M.K., Dandekar, A.M., Mcguire, P.E., Kluepfel, D.A., Dvorak, J., Lou, M. 2019. Sequencing a Juglans regia × J. microcarpa hybrid yields high-quality genome assemblies of parental species. Horticulture Research. 6:. https://doi.org/10.1038/s41438-019-0139-1.Shifts in soil bacterial communities as a function of carbon source used during anaerobic soil disinfestation-(Peer Reviewed Journal) Poret-Peterson, A.T., Albu, S., McClean, A.E., Kluepfel, D.A. 2019. Shifts in soil bacterial communities as a function of carbon source used during anaerobic soil disinfestation. Frontiers in Environmental Science. 6:160. https://doi.org/10.3389/FENVS.2018.00160.Variations in xylem embolism susceptibility under drought between intact saplings of three walnut species-(Peer Reviewed Journal) Knipfer, T., Barrios-Masias, F., Cuneo, I., Bouda, M., Albuquerque, C., Brodersen, C., Kluepfel, D.A., McElrone, A.J. 2018. Variations in xylem embolism susceptibility under drought between intact saplings of three walnut species. Tree Physiology. 38(8):1180-1192. https://doi.org/10.1093/treephys/tpy049.Genomic variation among and within six Juglans species-(Peer Reviewed Journal) Stevens, K.A., Woeste, K., Chakraborty, S., Crepeau, M.W., Leslie, C.A., Martinez-Garcia, P.J., Puiu, D., Romero-Severson, J., Coggeshall, M., Dandekar, A.M., Kluepfel, D.A., Neale, D.B., Salzberg, S.L., Langley, C.H. 2018. Genomic variation among and within six Juglans species. G3, Genes/Genomes/Genetics. 8(7):2153-2165. https://doi.org/10.1534/g3.118.200030.Draft genome sequence of agrobacterium tumefaciens biovar 1 strain 186, isolated from walnut-(Peer Reviewed Journal) Poret-Peterson, A.T., Bhatnagar, S., McClean, A.E., Kluepfel, D.A. 2017. Draft genome sequence of agrobacterium tumefaciens biovar 1 strain 186, isolated from walnut. Genome Announcements. 5(46):e01232-17. https://doi.org/10.1128/genomeA.01232-17.Screening almond rootstocks for sources of resistance to Armillaria root disease-(Peer Reviewed Journal) Baumgartner, K., Fujiyoshi, P.T., Ledbetter, C.A., Duncan, R., Kluepfel, D.A. 2018. Screening almond rootstocks for sources of resistance to Armillaria root disease. HortScience. 53(1):4-8. https://doi.org/10.21273/HORTSCI12038-17.Effect of anaerobic soil disinfestation on the bacterial community and key soilborne phytopathogenic agents under walnut tree-crop nursery conditions-(Peer Reviewed Journal) Strauss, S.L., Greenhut, R.F., Mcclean, A.E., Kluepfel, D.A. 2017. Effect of anaerobic soil disinfestation on the bacterial community and key soilborne phytopathogenic agents under walnut tree-crop nursery conditions. Plant and Soil. 415:493-506. doi:10.1007/s11104-016-3126-4.Vineyard soil bacterial diversity and composition revealed by 16S rRNA genes: Differentiation by vineyard management-(Peer Reviewed Journal) Burns, K.N., Bokulich, N.A., Cantu, D., Greenhut, R.F., Kluepfel, D.A., O'Geen, A.T., Strauss, S.L., Steenwerth, K.L. 2016. Vineyard soil bacterial diversity and composition revealed by 16S rRNA genes: Differentiation by vineyard management. Soil Biology and Biochemistry. 103:337-348. doi: 10.1016/j.soilbio.2016.09.007.Development of disease-resistant walnut rootstocks: Integration of conventional and genomic approaches (SCRI-match Year 3)-(Proceedings) Kluepfel, D.A., Leslie, C., Aradhya, M.K., Browne, G.T., Hasey, J., Pope, K., Mckenry, M., Westphal, A., Hackett, W., Bostock, R., Seybold, S., Dvorak, J., Luo, M., Coggeshall, M., Schlarbaum, S., Dandekar, A., Neale, D., Langley, C., Preece, J.E., Baumgartner, K. 2016. Development of disease-resistant walnut rootstocks: Integration of conventional and genomic approaches (SCRI-match Year 3). Walnut Research Conference. Walnut Research Reports 2015: 87-91.Vineyard soil bacterial diversity and composition revealed by 16S rRNA genes: differentiation by geographic features-(Peer Reviewed Journal) Burns, K.N., Kluepfel, D.A., Strauss, S.L., Bokulich, N.A., Cantu, D., Steenwerth, K.L. 2015. Vineyard soil bacterial diversity and composition revealed by 16S rRNA genes: differentiation by geographic features. Soil Biology and Biochemistry. 91:232-247. doi: 10.1016/j.soilbio.2015.09.002.Anaerobic soil disinfestation: a chemical-independent approach to pre-plant control of plant pathogens-(Peer Reviewed Journal) Strauss, S.L., Kluepfel, D.A. 2015. Anaerobic soil disinfestation: a chemical-independent approach to pre-plant control of plant pathogens. Journal of Integrative Agriculture. 14(11):2309-2318. doi: 10.1016/S2095-3119(15)61118-2.Patterns of drought-induced embolism formation and spread in living walnut saplings visualized using x-ray microtomography-(Peer Reviewed Journal) Knipfer, T., Brodersen, C., Zedan, A., Kluepfel, D.A., Mcelrone, A.J. 2015. Patterns of drought-induced embolism formation and spread in living walnut saplings visualized using x-ray microtomography. Tree Physiology. doi: 10.1093/treephys/tpv040.Identification of Juglans wild relatives resistant to crown gall caused by Agrobacterium tumefaciens-(Peer Reviewed Journal) Kluepfel, D.A., Mcclean, A.E., Aradhya, M.K., Moersfelder, J.W. 2015. Identification of Juglans wild relatives resistant to crown gall caused by Agrobacterium tumefaciens. Acta Horticulturae. 1074:87-94.Genetic conservation, characterization and utilization of wild relatives of fruit and nut crops at the USDA Germplasm Repository in Davis, California-(Peer Reviewed Journal) Aradhya, M.K., Preece, J.E., Kluepfel, D.A. 2015. Genetic conservation, characterization and utilization of wild relatives of fruit and nut crops at the USDA Germplasm Repository in Davis, California. Acta Horticulturae. 1074:95-104.Impact of biological amendments on Agrobacterium tumefaciens soil survival-(Peer Reviewed Journal) Strauss, S.L., Stover, D.A., Kluepfel, D.A. 2014. Impact of biological amendments on Agrobacterium tumefaciens soil survival. Applied Soil Ecology. 87:39-48.Effect of anaerobic soil disinfestation and vermicompost on soilborne phytopathogenic agents under tree-crop nursery conditions-(Abstract Only)Development of disease-resistant walnut rootstocks: Integration of conventional and genomic approaches-(Proceedings) Kluepfel, D.A., Browne, G.T., Mckenry, M., Hasey, J., Leslie, C., Aradhya, M.K., Hackett, W., Preece, J.E., Bostock, R., Seybold, S. 2014. Development of disease-resistant walnut rootstocks: Integration of conventional and genomic approaches. Walnut Research Conference. 77-87.Incidence of Agrobacterium tumefaciens biovar 1 in and on ‘Paradox’ (Juglans hindsii x Juglans regia) walnut seed collected from commercial nurseries-(Peer Reviewed Journal) Yakabe, L.E., Parker, S.R., Kluepfel, D.A. 2014. Incidence of Agrobacterium tumefaciens biovar 1 in and on ‘Paradox’ (Juglans hindsii x Juglans regia) walnut seed collected from commercial nurseries. Plant Disease. 98:766-770.Evaluating paradox walnut rootstocks for resistance to Armillaria root disease-(Peer Reviewed Journal) Baumgartner, K., Fujiyoshi, P.T., Browne, G.T., Leslie, C., Kluepfel, D.A. 2013. Evaluating paradox walnut rootstocks for resistance to Armillaria root disease. HortScience. 48:68-72.Identification of tree-crop rootstocks with resistance to Armillaria root disease.-(Abstract Only) Baumgartner, K., Fujiyoshi, P.T., Kluepfel, D.A., Browne, G.T., Leslie, C. 2012. Identification of tree-crop rootstocks with resistance to Armillaria root disease.. American Phytopathological Society Abstracts. 23-0.Comparative genomics of plant-associated Pseudomonas spp.: Insights into diversity and inheritance of traits involved in multitrophic interactions-(Peer Reviewed Journal) Loper, J.E., Hassan, K.A., Mavrodi, D., Davis, E.W., Lim, C., Shaffer, B.T., Elbourne, L.H., Stockwell, V.O., Hartney, S.L., Breakwell, K., Henkels, M.D., Tetu, S.G., Rangel, L.I., Kidarsa, T.A., Wilson, N.L., Van Mortel, J., Song, C., Blumhagen, R., Radune, D., Hostetler, J.B., Brinkac, L.M., Durkin, A., Kluepfel, D.A., Wechter, W.P., Anderson, A.J., Kim, Y., Pierson Iii, L.S., Pierson, E.A., Lindow, S.E., Raaijmakers, J.M., Weller, D.M., Thomashow, L.S., Allen, A.E., Paulsen, I.I. 2012. Comparative genomics of plant-associated Pseudomonas spp.: Insights into diversity and inheritance of traits involved in multitrophic interactions. PLoS Genetics. 8(7):e1002784.The quest to identify disease resistance in the USDA-ARS Juglans germplasm collection-(Peer Reviewed Journal) Kluepfel, D.A., Aradhya, M.K., Browne, G.T., Mckenry, M.V., Leslie, C.A., Mcclean, A.E., Moersfelder, J.W., Velasco, D.M., Baumgartner, K. 2012. The quest to identify disease resistance in the USDA-ARS Juglans germplasm collection. Acta Horticulturae. 948:105-111.Soil solarization and biological control for managing Mesocriconema xenoplax and Short Life in a newly established peach orchard-(Peer Reviewed Journal) Nyczepir, A.P., Kluepfel, D.A., Waldrop, V., Wechter, W.P. 2012. Soil solarization and biological control for managing Mesocriconema xenoplax and Short Life in a newly established peach orchard. Plant Disease. 96:1309-1314.Proceedings of the first international symposium on wild relatives of subtropical and temperate fruit and nut crops-(Proceedings) Kluepfel, D.A., Aradhya, M.K., (Editors), 2012. Proceedings of the First International Symposium on Wild Relatives of Subtropical and Temperate Fruit and Nut Crops. Belgium. Acta Horticulturae 948.Novel primers for detection of genetically diverse virulent Agrobacterium tumefaciens bv1 strains-(Peer Reviewed Journal) Yakabe, L.E., Maccree, M.M., Sudarshana, P., Mcclean, A.E., Parker, S.R., Wechter, W.P., Presting, G., Kluepfel, D.A. 2012. Novel primers for detection of genetically diverse virulent Agrobacterium tumefaciens bv1 strains. Journal of General Plant Pathology. DOI: 10.1007/s10327-012-0364-z.Clonal propagation of walnut rootstock genotypes for genetic improvement 2011-(Proceedings) Clonal propagation of walnut rootstock genotypes for genetic improvement 2011. Walnut Research Conference. 2011:103-128.Evaluation of wild juglans species for crown gall resistance-(Abstract Only) Kluepfel, D.A., Mcclean, A.E., Aradhya, M.K., Moersfelder, J.W., Dull, A., Marsden, C., Hackett, W. 2012. Evaluation of wild juglans species for crown gall resistance. Walnut Research Conference. 313-317.Evaluations and modifications of semi-selective media for improved isolation of Agrobacterium tumefaciens biovar 1 from cultivated walnut-(Abstract Only) Yakabe, L.E., Parker, S.R., Kluepfel, D.A. 2011. Evaluations and modifications of semi-selective media for improved isolation of Agrobacterium tumefaciens biovar 1 from cultivated walnut. Phytopathology. 101:S196.Evaluation of wild walnut Juglans spp. for resistance to crown gall disease-(Abstract Only) Kluepfel, D.A., Aradhya, M.K., Moersfelder, J.W., Mcclean, A.E., Hackett, W.P., Dull, A.J. 2011. Evaluation of wild walnut Juglans spp. for resistance to crown gall disease. Phytopathology. 101:S92.FIRST INTERNATIONAL SYMPOSIUM ON WILD RELATIVES OF SUBTROPICAL AND TEMPERATE FRUIT AND NUT CROPS-(Peer Reviewed Journal) Koehmstedt, A., Velasco, D., Aradhya, M.K., Kluepfel, D.A. 2011. FIRST INTERNATIONAL SYMPOSIUM ON WILD RELATIVES OF SUBTROPICAL AND TEMPERATE FRUIT AND NUT CROPS. Symposium Proceedings. 51:38-39.Clonal Propagation of walnut rootstock genotypes for genetic improvement 2010-(Proceedings) Hackett, W., Leslie, C., Grant, J., Lampinen, B., Mcgranahan, G., Anderson, K., Beede, B., Buchner, R., Caprile, J., Debuse, C., Hasey, J., Manterola, N., Robinson, R., Kluepfel, D.A., Browne, G.T., Mckenry, M. 2011. Clonal Propagation of walnut rootstock genotypes for genetic improvement 2010. Walnut Research Conference. 2010:65-82.Evaluation of wild Juglans species for crown gall resistance-(Proceedings) Kluepfel, D.A., Aradhya, M.K., Moersfelder, J.W., Mcclean, A.E., Maccree, M.M., Hackett, W. 2011. Evaluation of wild Juglans species for crown gall resistance. Walnut Research Conference. 2010:239-252.Genomic Diversity of Biocontrol Strains of Pseudomonas spp. Isolated from Aerial or Root Surfaces of Plants-(Abstract Only) Loper, J.E., Davis, E.W., Lim, K., Hassan, K., Wilson, N., Hartney, S., Shaffer, B.T., Stockwell, V., Henkels, M.D., Shen, K., Blumhagen, R.Z., Mavrodi, D., Van Mortel, J., Song, C., Radune, D., Hostetler, J., Kluepfel, D.A., Wechter, W.P., Anderson, A., Young, C., Pierson, L., Pierson, E., Lindow, S., Raaijmakers, J., Weller, D.M., Thomashow, L.S., Allen, A., Paulsen, I. 2010. Genomic diversity of biocontrol strains of Pseudomonas spp. isolated from aerial or root surfaces of plants. International Symposium on Microbiology of Aerial Plant Surfaces Program Book. p.43.THE ROLE OF TYLOSES IN CROWN HYDRAULIC FAILURE OF MATURE WALNUT TREES AFFLICTED WITH APOPLEXY DISORDER-(Peer Reviewed Journal) Mcelrone, A.J., Grant, J.A., Kluepfel, D.A. 2010. THE ROLE OF TYLOSES IN CROWN HYDRAULIC FAILURE OF MATURE WALNUT TREES AFFLICTED WITH APOPLEXY DISORDER. Tree Physiology. 30:761-772.Evaluation of wild juglans species for crown gall resistance-(Research Technical Update) Kluepfel, D.A., Aradhya, M.K., Maccree, M., Moersfelder, J.W., Mcclean, A.E., Hackett, W. 2011. Evaluation of wild juglans species for crown gall resistance. Walnut Research Conference. pp. 239-242.Effect of pre-plant soil fumigants on Agrobacterium tumefaciens, pythiaceous species, and subsequent soil recolonization by A. tumefaciens-(Peer Reviewed Journal) Yakabe, L., Parker, S., Kluepfel, D.A. 2010. Effect of pre-plant soil fumigants on Agrobacterium tumefaciens, pythiaceous species, and subsequent soil recolonization by A. tumefaciens. Crop Protection. 29:583-590.CROWN GALL INCIDENCE: SEEDLING PARADOX WALNUT ROOTSTOCK VERSUS OWN-ROOTED ENGLISH WALNUT TREES-(Peer Reviewed Journal) Hasey, J., Lampinen, B., Anderson, K., Grant, J., Caprile, J., Beede, R., Kluepfel, D.A. 2010. CROWN GALL INCIDENCE: SEEDLING PARADOX WALNUT ROOTSTOCK VERSUS OWN-ROOTED ENGLISH WALNUT TREES. Acta Horticulturae. 861:453-455.DETECTION AND IMPLICATIONS OF EARLY AGROBACTERIUM TUMEFACIENS INFECTION OF PARADOX SEEDS AND SEEDLINGS-(Peer Reviewed Journal) Kluepfel, D.A., Yakabe, L., Parker, S., Mcclean, A.E., Maccree, M.M. 2010. DETECTION AND IMPLICATIONS OF EARLY AGROBACTERIUM TUMEFACIENS INFECTION OF PARADOX SEEDS AND SEEDLINGS. Acta Horticulturae. 861:497-500.Clonal Propagation of Walnut Rootstock Genotypes for Genetic Improvement 2009-(Proceedings) Hackett, W., Leslie, C., Mcgranahan, G., Kluepfel, D.A., Lampinen, B., Anderson, K., Beede, B., Buchner, R., Debuse, C., Grant, J., Hasey, J., Caprile, J., Manterola, N. 2010. Clonal Propagation of Walnut Rootstock Genotypes for Genetic Improvement 2009. Walnut Research Conference. pp 71-86.GENETIC LOCI INVOLVED IN RUBRIFACINE PRODUCTION IN THE WALNUT PATHOGEN BRENNARIA RUBRIFACIENS-(Peer Reviewed Journal) Mcclean, A.E., Kluepfel, D.A. 2009. GENETIC LOCI INVOLVED IN RUBRIFACINE PRODUCTION IN THE WALNUT PATHOGEN BRENNARIA RUBRIFACIENS. Phytopathology. 99:145-151.PSEUDOMONAS GENE EXPRESSION DURING GROWTH IN THE RHIZOSPHERE-(Abstract Only) Gonzalez, E.T., Wechter, W.P., Kluepfel, D.A. 2008. Pseudomonas gene expression during growth in the rhizosphere. Phytopathology. 98 (6 supplements):S191Involvement of sensor kinase gene (skrp 1122) for biocontrol activity by Pseudomonas synxantha BG33R-(Abstract Only) Fang, G.C., Waldrop, V., Wechter, W.P., Kluepfel, D.A. 2008. Involvement of sensor kinase gene (skrp 1122) for biocontrol activity by Pseudomonas synxantha BG33R. Phytopathology. 98 (6 supplements):S52.  . American Phytopathological Society Annual Meeting.Impact of Pseudomonas-based biocontrol agents and solarization on Mesocriconema xenoplax populations and tree survival in a peach tree short life site-(Abstract Only) Nyczepir, A.P., Kluepfel, D.A., Wechter, W.P. 2008. Impact of Pseudomonas-based biocontrol agents and solarization on Mesocriconema xenoplax populations and tree survival in a peach tree short life site [abstract]. International Congress of Nematology. 5:299.ENHANCED DETECTION AND ISOLATION OF THE WALNUT PATHOGEN BRENNARIA RUBRIFACIENS: CAUSAL AGENT OF DEEP BARK CANKER-(Peer Reviewed Journal) Mcclean, A.E., Sudarshana, P., Kluepfel, D.A. 2008. Enhanced detection and isolation of the walnut pathogen brennaria rubrifaciens: causal agent of deep bark canker. European Journal of Plant Pathology. 10.1007/s 10658-008-9308Evaluaton of Wild Juglans Species for Crown Gall Resistance-(Proceedings) Stover, E.W., Maccree, M.M., Aradhya, M.K., Mcclean, A.E., Kluepfel, D.A. 2008. Evaluaton of Wild Juglans Species for Crown Gall Resistance. Walnut Research Conference.Biology of Brenneria Rubrifaciens:  Screening for genes involved in pathogenesis-(Proceedings) Mcclean, A.E., Kluepfel, D.A. 2008. Biology of Brenneria Rubrifaciens:  Screening for genes involved in pathogenesis  . Walnut Research Conference.Assessing the Genetic Diversity of Agrobacterium Tumefaciens in CA Walnut Growing Regions and Resistance to the Biocontrol Agent, A. Rhizogenes K84-(Proceedings) Gonzalez, E.T., Maccree, M.M., Zaid, M., Kluepfel, D.A. 2008. Assessing the Genetic Diversity of Agrobacterium Tumefaciens in CA Walnut Growing Regions and Resistance to the Biocontrol Agent, A. Rhizogenes K84. Walnut Research Conference.Nonchemical alternatives for managing phytoparasitic nematodes in peach: biological agents, solarization, preplant groundcovers-(Proceedings) Nyczepir, A.P., Kluepfel, D.A. 2008. Nonchemical alternatives for managing phytoparasitic nematodes in peach: biological agents, solarization, preplant groundcovers. In: Proceedings of the Southeastern Peach Convention, January 11-13, 2008, Savannah, Georgia. p. 12-15.A BROAD-SPECTRUM ANTAGONISTIC ACTIVITY OF THE BIOCONTROL AGENT PSEUDOMONAS SYNXANTHA BG33R-(Abstract Only) Fang, G.C., Wechter, W.P., Kluepfel, D.A. 2007. A BROAD-SPECTRUM ANTAGONISTIC ACTIVITY OF THE BIOCONTROL AGENT PSEUDOMONAS SYNXANTHA BG33R. American Phytopathological Society Abstracts.SOIL MORPHOLOGY, DEPTH AND GRAPEVINE ROOT FREQUENCY INFLUENCE MICROBIAL COMMUNITIES IN A PINOT NOIR VINEYARD-(Peer Reviewed Journal) Steenwerth, K.L., Drenovsky, R.E., Lambert, J.J., Smart, D.R., Kluepfel, D.A., Scow, K.M. 2008. SOIL MORPHOLOGY, DEPTH AND GRAPEVINE ROOT FREQUENCY INFLUENCE MICROBIAL COMMUNITIES IN A PINOT NOIR VINEYARD. Soil Biology and Biochemistry. 40:1330-1340.Impact of solarization, rootstock and Pseudomonas synxantha on Criconemoides xenoplax populations and tree growth in peach tree short life site-(Abstract Only) Nyczepir, A.P., Kluepfel, D.A. 2007. Impact of solarization, rootstock and Pseudomonas synxantha on Criconemoides xenoplax populations and tree growth in peach tree short life site [abstract]. Journal of Nematology. 39:75.Microarray analysis:  Uses and Limitations-(Abstract Only) Wechter, W.P., Levi, A., Kluepfel, D.A., Gonzalez, E.T., Presting, G. 2007. Microarray Analysis:  Uses and Limitations. HortScience.  42:477.REAL-TIME PCR DETECTION AND DEVELOPMENT OF A BIOASSAY FOR THE DEEP BARK CANKER PATHOGEN, BRENNARIA RUBRIFACIENS-(Proceedings) Mcclean, A.E., Sudarshana, P., Kluepfel, D.A. 2007. Real-time pcr detection and development of a bioassay for the deep bark canker pathogen, brennaria rubrifaciens. Walnut Research Conference.EVALUATION OF WILD JUGLANS SPECIES FOR CROWN GALL RESISTANCE-(Proceedings) Stover, E.W., Maccree, M.M., Aradhya, M.K., Mcclean, A.E., Kluepfel, D.A. 2007. Evaluation of wild juglans species for crown gall resistance. Walnut Research Conference.DEVELOPMENT OF A CULTURE-INDEPENDENT REAL-TIME PCR ASSAY FOR DETECTION OF AGROBACTERIUM TUMEFACIENS IN SOIL-(Peer Reviewed Journal) Sudarshana, P., Mcclean, A.E., Kluepfel, D.A. 2006. Development of a culture-independent real-time pcr assay for detection of agrobacterium tumefaciens in soil. Walnut Research Conference.EFFECTS OF GRAPEVINE ROOTS, SOIL RESOURCES AND DEPTH ON SOIL MICROBIAL COMMUNITIES IN A PINOT NOIR VINEYARD-(Abstract Only) Steenwerth, K.L., Parker, S., Kluepfel, D.A., Lambert, J., Smart, D.R. 2006. Effects of grapevine roots, soil resources and depth on soil microbial communities in a pinot noir vineyard. World Congress of Soil Science.SEASONAL FLUCTUATION OF AGROBACTERIUM TUMEFACIENS POPULATIONS IN WALNUT ORCHARD SOIL-(Abstract Only) Kluepfel, D.A., Sudarshana, P. 2006. Seasonal fluctuation of agrobacterium tumefaciens populations in walnut orchard soil. American Phytopathological Society Annual Meeting.DETECTION OF BRENNARIA RUBRIFACIENS THE CAUSATIVE AGENT OF DEEP BARK CANKER (DBC)OF WALNUT-(Abstract Only) Mcclean, A.E., Sudarshana, P., Kluepfel, D.A. 2006. Detection of brennaria rubrifaciens the causative agent of deep bark canker (dbc)of walnut. American Phytopathological Society Annual Meeting.DEVELOPMENT OF A PCR-BASED METHOD FOR THE DETECTION OF BRENNARIA RUBRIFACIENS; THE CAUSAL AGENT OF DEEP BARK CANKER OF WALNUT-(Peer Reviewed Journal) Mcclean, A.E., Sudarshana, P., Kluepfel, D.A. 2006. Development of a pcr-based method for the detection of brennaria rubrifaciens; the causal agent of deep bark canker of walnut. Walnut Research Conference.ANALYSIS OF SOIL PROPERTIES AND BACTERIAL GENERA INFLUENCING THE SOIL-BORNE CULTURABLE BACTERIAL COMMUNITY IN A CALIFORNIA GRAPEVINE VINEYARD-(Abstract Only) Parker, S.R., Kluepfel, D.A., Steenwerth, K.L., Lambert, J., Smart, D. 2006. Analysis of soil properties and bacterial genera influencing the soil-borne culturable bacterial community in a california grapevine vineyard. American Phytopathological Society Abstracts.EFFECT OF TEMPERATURE AND DETERGENTS ON AGROBACTERIUM TUMEFACIENS, THE CAUSAL PATHOGEN OF CROWN GALL DISEASE OF WALNUT-(Abstract Only) Sudarshana, P., Mcclean, A.E., Kluepfel, D.A. 2006. Effect of temperature and detergents on agrobacterium tumefaciens, the causal pathogen of crown gall disease of walnut. American Phytopathological Society Abstracts.GLOBAL GENE EXPRESSION OF PSEUDOMONAS PUTIDA KT2440 DURING GROWTH IN THE RHIZOSPHERE OF ARABIDOPSIS THALIANA-(Abstract Only) Wechter, W.P., Kluepfel, D.A. 2005. Global gene expression of Pseudomonas Putida KT2440 during growth in the rhizosphere of Arabidopsis Thaliana [abstract]. Phytopathology 95 (6):S110.INSERTIONS IN THE AVIRULENCE GENE AVRA ALTER THE VIRULENCE OF RALSTONIA SOLANACEARUM ON NICOTIANA TABACUM.-(Book / Chapter) Robertson, A.E., Fortnum, B.A., Wechter, W.P., Denny, T.P., Kluepfel, D.A. 2005.  Insertions in the avirulence gene avra alter the virulence of Ralstonia solanacearum on Nicotiana tabacum. In:  Allen, C., Prior, P., and Hayward, A.C., eds.  Bacterial Wilt and the Disease and Ralstonia solanacearum species Complex.  St. Paul, MN: APS Press. p 359-364.MECHANIZATION HAS CONTRIBUTED TO THE SPREAD OF BACTERIAL WILT ON FLUE-CURED TOBACCO IN THE SOUTHEASTERN USA-(Book / Chapter) Fortnum, B.A., Kluepfel, D.A. 2005. Mechanization has contributed to the spread of bacterial wilt on flue-cured tobacco in the southeastern usa. Bacterial Wilt, The Disease and Ralstonia Solanacearum Species Complex.INSERTIONS IN THE AVIRULENCE GENE AVRA ALTHER THE VIRULENCE OF RALSTONIA SOLANACEARUM ON NICOTIANA TABACUM-(Book / Chapter) Robertson, A.E., Fortnum, B.A., Wechter, W.P., Denny, T.P., Kluepfel, D.A. 2005. Insertions in the avirulence gene avra alther the virulence of ralstonia solanacearum on nicotiana tabacum. Bacterial Wilt, The Disease and Ralstonia Solanacearum Species Complex.BIOLOGY AND MANAGEMENT OF REPLANT DISORDER AND LETHAL PHYTOPHTHORA CANKER-(Proceedings) Kluepfel, D.A., Browne, G.T. Biology and management of replant disorder and lethal phytophthora canker. Almond Industry Conference Proceedings. 2004INVESTIGATION OF THE POSSIBLE CAUSES OF AN UNIDENTIFIED COTTON SEED ROT-(Proceedings) JONES, M.A., MUELLER, J., KLUEPFEL, D.A. INVESTIGATION OF THE POSSIBLE CAUSES OF AN UNIDENTIFIED COTTON SEED ROT. Cotton Incorporated Proceedings. 2002.  ProjectsImproved Pest and Disease Control for Enhanced Woody Perennial Tree Crop and Grapevine ProductionIn-House Appropriated (D)Accession Number:441857Impact of Wood-infecting Fungi on Horticultural CropsNon-Assistance Cooperative Agreement (S)Accession Number:442345 **Research Program:** Dr. Kluepfel's research program explores the interaction between plants and bacteria at the interface between roots and the surrounding soil called the rhizosphere. The aim of the research is to characterize both individual bacterial species and the microbial community which occupy the rhizopshere of important fruit and nut crops such as walnut, almonds and grapes and understand how they interact and communicate with their plant hosts. Toward this end, different model plant-bacteria systems are being examined. The laboratory is examining, the behavior and pathogenecity of Agrobacterium tumefaciens, the cause of Crown Gall Disease, on walnut. In addition, a project to detect and characterize the bacterial pathogen, Brenneria rubrifaciens, that causes deep bark canker on walnut is underway. These projects are all supported by our effort to isolate and characterize all the bacterial genes whose expression is modulated by plant-root exudates during bacterial growth in the rhizosphere. This information is being used to identify individual microbial species and/or microbial communities that are beneficial to plant health and antagonistic to disease causing pathogens in the soil in an effort to develop ecologically sustainable disease control methods employing naturally occurring soil bacteria. **Biography:** Dr. Daniel Kluepfel received a BA in Biology from the University of Missouri, St. Louis and then went on to receive his Ph.D. in Plant Pathology, with a minor Microbiology, from the University of Florida, Gainesville. His Ph.D. research examined the attachment of plant associated bacteria to solid surfaces. After graduation Dr. Kluepfel accepted a Fulbright Fellowship to conduct post doctoral work at the Agriculture University of the Netherlands in Wageningen. This was followed by a second post doctoral position at the University of Hawaii in the Department of Plant Pathology where he was involved in the genetic characterization of toxin production by phytopathogenic bacteria. Dr. Kluepfel served on the faculty of the Department of Plant Pathology and Physiology at Clemson University in South Carolina from 1987-2003. In 2003 Dr. Kluepfel joined the USDA/ARS in Davis, CA.


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