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Ivan Simko
Crop Improvement and Protection Research
Research Geneticist (Plants)

Phone: (831) 755-2862
Fax: (831) 755-2814

1636 E ALISAL ST
SALINAS, CA 93905
Projects
Genetics and Breeding of Lettuce, Spinach, Melon, and Related Species to Improve Production and Consumer-related Traits
In-House Appropriated (D)
  Accession Number: 434549
Improved Management of Strawberry and Lettuce Soilborne Plant Pathogens using Microbiome-Based Disease Prediction
Reimbursable Cooperative Agreement (R)
  Accession Number: 433968
Identifying the Basis of Lettuce Drop Resistance to Develop Cultivars with Superior Resistance
Reimbursable Cooperative Agreement (R)
  Accession Number: 437616
Improving Lettuce Cultivars against Bacterial Leaf Spot (BLS) through Breeding, Genetics, and Study of the BLS-Lettuce Interaction
Reimbursable Cooperative Agreement (R)
  Accession Number: 439349
Identifying the Basis of Lettuce Drop Resistance to Develop Cultivars With Superior Resistance
Non-Assistance Cooperative Agreement (S)
  Accession Number: 437875
New Lettuce Cultivars with Resistance to Lettuce Drop
Non-Assistance Cooperative Agreement (S)
  Accession Number: 433019
Improved Management of Strawberry and Lettuce Soilborne Plant Pathogens Using Microbiome-Based Disease Prediction
Non-Assistance Cooperative Agreement (S)
  Accession Number: 436428
Lettuce Breeding and Genetics (2020)
Trust Fund Cooperative Agreement (T)
  Accession Number: 437848

Publications (Clicking on the reprint icon Reprint Icon will take you to the publication reprint.)
Clustering of soil sample microbiomes using metagenomic shotgun sequencing data - (Abstract Only)
Mammel, M., Leonard, S.R., Richter, T., Simko, I., Brandl, M. 2020. Clustering of soil sample microbiomes using metagenomic shotgun sequencing data. FDA Foods Program Regulatory Science Conference, September 1, 2020, College Park, Maryland.
Content of chlorophylls and anthocyanins in leaves and their relationship to color and conceptual midpoint quasi-color (database) Reprint Icon ()
Simko, I. 2020. Content of chlorophylls and anthocyanins in leaves and their relationship to color and conceptual midpoint quasi-color (database). TRY: Plant Trait Database. https://doi.org/10.17871/TRY.66.
Predictive modeling of a leaf conceptual midpoint quasi-color (CMQ) using an artificial neural network Reprint Icon - (Peer Reviewed Journal)
Simko, I. 2020. Predictive modeling of a leaf conceptual midpoint quasi-color (CMQ) using an artificial neural network. Sensors. 20(14):3938. https://doi.org/10.3390/s20143938.
Genome sequence of Verticillium dahliae race 1 isolate VdLs.16 from lettuce Reprint Icon - (Peer Reviewed Journal)
Chen, J.-Y., Zhang, D.-D., Huang, J.-Q., Wang, D., Hao, S.-J., Li, R., Puri, K.D., Yang, L., Tong, B.-Z., Xiong, K.-X., Simko, I., Klosterman, S.J., Subbarao, K.V., Dai, X.-F. 2020. Genome sequence of Verticillium dahliae race 1 isolate VdLs.16 from lettuce. Molecular Plant-Microbe Interactions. https://doi.org/10.1094/MPMI-04-20-0103-A.
Resistance to bacterial leaf spot in baby leaf lettuce - (Abstract Only)
Sthapit Kandel, J., Sandoya, G.V., Mou, B., Simko, I. 2020. Resistance to bacterial leaf spot in baby leaf lettuce. American Society of Horticulture Science Annual Conference, August 9-13, 2020, Orlando, Florida.
Insight into deterioration of fresh-cut lettuce in modified atmosphere packaging - (Abstract Only)
Peng, H., Lavelle, D., Truco, M.-J., Michelmore, R., Simko, I. 2020. Insight into deterioration of fresh-cut lettuce in modified atmosphere packaging. American Society for Horticultural Science Annual Conference, August 9-13, 2020, Orlando, Florida.
Genome-wide association mapping reveals loci for shelf life and developmental rate of lettuce Reprint Icon - (Peer Reviewed Journal)
Sthapit Kandel, J., Peng, H., Hayes, R.J., Mou, B., Simko, I. 2020. Genome-wide association mapping reveals loci for shelf life and developmental rate of lettuce. Theoretical and Applied Genetics. 133:1947–1966. https://doi.org/10.1007/s00122-020-03568-2.
Genetic variation in response to N, P, or K deprivation in baby leaf lettuce Reprint Icon - (Peer Reviewed Journal)
Simko, I. 2020. Genetic variation in response to N, P, or K deprivation in baby leaf lettuce. Horticulturae. 6(1):15. https://doi.org/10.3390/horticulturae6010015.
Genetics of extended storage life ()
Simko, I., Sthapit Kandel, J., Peng, H., Hayes, R.J., Truco, M.J., Michelmore, R.W. 2020. Genetics of extended storage life. Future of Lettuce Conference, March 16, 2020, Pismo Beach, California.
Factors, physiology, and genetics associated with the deterioration of fresh-cut lettuce in modified atmospheres ()
Peng, H., Lavelle, D., Truco, M., Michelmore, R., Simko, I. 2020. Factors, physiology, and genetics associated with the deterioration of fresh-cut lettuce in modified atmospheres. Future of Lettuce Conference, March 16, 2020, Pismo Beach, California.
Genetic diversity, linkage disequilibrium and genome-wide association studies in lettuce - (Abstract Only)
Sthapit Kandel, J., Mou, B., Simko, I., Hayes, R.J. 2020. Genetic diversity, linkage disequilibrium and genome-wide association studies in lettuce. Plant and Animal Genome Conference, January 11-15, 2020, San Diego, California.
Phenomic and physiological analysis of salinity effects on lettuce Reprint Icon - (Peer Reviewed Journal)
Adhikari, N.D., Simko, I., Mou, B. 2019. Phenomic and physiological analysis of salinity effects on lettuce. Sensors. 19(21):4814. https://doi.org/10.3390/s19214814.
Genetic analysis of resistance to bacterial leaf spot in the heirloom lettuce cultivar Reine des Glaces Reprint Icon - (Peer Reviewed Journal)
Sandoya, G.V., Maisonneuve, B., Truco, M.J., Bull, C.T., Simko, I., Trent, M., Hayes, R.J., Michelmore, R.W. 2019. Genetic analysis of resistance to bacterial leaf spot in the heirloom lettuce cultivar Reine des Glaces. Molecular Breeding. 39:160. https://doi.org/10.1007/s11032-019-1072-6.
Lettuce and spinach breeding ()
Simko, I., McCreight, J.D., Mou, B., Richardson, K.L. 2019. Lettuce and spinach breeding. California Leafy Greens Research Program Mid-Year Meeting, October 8, 2019, Salinas, California.
Genetic variation and relationship among content of vitamins, pigments, and sugars in baby leaf lettuce Reprint Icon - (Peer Reviewed Journal)
Simko, I. 2019. Genetic variation and relationship among content of vitamins, pigments, and sugars in baby leaf lettuce. Food Science and Nutrition. 7(10):3317–3326. https://doi.org/10.1002/fsn3.1196.
The LsVe1L allele provides a molecular marker for resistance to Verticillium dahliae race 1 in lettuce Reprint Icon - (Peer Reviewed Journal)
Inderbitzin, P., Christopoulou, M., Lavelle, D., Reyes-Chin-Wo, S., Michelmore, R.W., Subbarao, K.V., Simko, I. 2019. The LsVe1L allele provides a molecular marker for resistance to Verticillium dahliae race 1 in lettuce. Biomed Central (BMC) Plant Biology. 19:305. https://doi.org/10.1186/s12870-019-1905-9.
Identification of romaine lettuce (Lactuca sativa var. longifolia) varieties with reduced browning discoloration for fresh-cut processing Reprint Icon - (Peer Reviewed Journal)
Luo, Y., Bornhorst, E., Teng, Z., Zhou, B., Park, E., Turner, E.R., Simko, I. 2019. Identification of romaine lettuce (Lactuca sativa var. longifolia) varieties with reduced browning discoloration for fresh-cut processing. Postharvest Biology and Technology. 156:110931. https://doi.org/10.1016/j.postharvbio.2019.110931.
Identifying QTL for the control of flowering time under multiple environments in lettuce - (Abstract Only)
Rosental, L., You, Y., Hayes, R.J., Still, D., Simko, I. 2019. Identifying QTL for the control of flowering time under multiple environments in lettuce. Israeli Society of Field and Vegetable Crops Conference, May 27, 2019, Rehovot, Israel.
The genetics of resistance to lettuce drop (Sclerotinia spp.) in lettuce in a recombinant inbred line population from Batavia Reine des Glaces x Eruption Reprint Icon - (Peer Reviewed Journal)
Mamo, B.E., Hayes, R.J., Truco, M., Puri, K.D., Michelmore, R.W., Subbarao, K.V., Simko, I. 2019. The genetics of resistance to lettuce drop (Sclerotinia spp.) in lettuce in a recombinant inbred line population from Batavia Reine des Glaces x Eruption. Theoretical and Applied Genetics. 132(8):2439-2460. https://doi.org/10.1007/s00122-019-03365-6.
Genetic architecture of tipburn resistance in lettuce Reprint Icon - (Peer Reviewed Journal)
Macias Gonzalez, M., Truco, M.J., Bertier, L., Jenni, S., Simko, I., Hayes, R.J., Michelmore, R.W. 2019. Genetic architecture of tipburn resistance in lettuce. Theoretical and Applied Genetics. 132(8):2209–2222. https://doi.org/10.1007/s00122-019-03349-6.
Trends in lettuce and spinach production in the United States - (Abstract Only)
Simko, I., Mou, B., Richardson, K.L., McCreight, J.D. 2019. Trends in lettuce and spinach production in the United States. EUCARPIA Leafy Vegetables International Conference, June 24-28, 2019, Olomouc, Czech Republic.
Lettuce genetics of lettuce drop and Verticillium wilt resistance - (Abstract Only)
Mamo, B., Hayes, R.J., Simko, I., Subbarao, K.V. 2019. Lettuce genetics of lettuce drop and Verticillium wilt resistance. Soilborne Plant Pathogens Conference, March 26-28, 2019, San Marino, CA.
Variation in nutrient contents and retention in fresh-cut lettuce - (Abstract Only)
Sthapit Kandel, J., Mou, B., Simko, I., Hayes, R.J. 2019. Variation in nutrient contents and retention in fresh-cut lettuce. American Society for Horticultural Science Annual Conference, July 21-25, 2019, Las Vegas, Nevada.
Marker-assisted selection in lettuce breeding - (Abstract Only)
Simko, I. 2019. Marker-assisted selection in lettuce breeding. EUCARPIA Leafy Vegetables International Conference, June 24-28, 2019, Olomouc, Czech Republic.
Phenolics composition in lettuce upon ultraviolet radiation and temperature effects - (Abstract Only)
Sytar, O., Zivcak, M., Brestic, M., Rauh, C., Simko, I. 2019. Phenolics composition in lettuce upon ultraviolet radiation and temperature effects. Alps-Adria Scientific Workshop, April 1-6, 2019, Rimini, Italy.
Lettuce and Spinach Breeding ()
Simko, I., Mou, B., McCreight, J.D., Richardson, K.L. 2019. Lettuce and Spinach Breeding. California Leafy Greens Research Program Meeting, March 19, 2019, Pismo Beach, CA.
Understanding salt tolerance in lettuce - (Abstract Only)
Adhikari, N.D., Soria, A., Simko, I., Mou, B. 2019. Understanding salt tolerance in lettuce. American Society of Horticultural Science Annual Meeting, July 21-25, 2019, Las Vegas, NV.
Understanding deterioration of fresh-cut lettuce in modified atmosphere packaging - (Abstract Only)
Peng, H., Lavelle, D., Truco, M.J., Zhao, R.B., Michelmore, R., Simko, I. 2019. Understanding deterioration of fresh-cut lettuce in modified atmosphere packaging. American Society for Horticultural Science Annual Conference, July 21-25, 2019, Las Vegas, Nevada.
Identifying QTL for the control of flowering time under multiple environments in lettuce ()
Rosental, L., You, Y., Hayes, R.J., Still, D., Simko, I. 2019. Identifying QTL for the control of flowering time under multiple environments in lettuce. Israeli Society of Plant Sciences Conference, February 13, 2019, Sede Boqer, Israel.
Lettuce breeding and genetics. Resistance to diseases, improved quality, molecular markers ()
Simko, I. 2018. Lettuce breeding and genetics. Resistance to diseases, improved quality, molecular markers. Plant Breeding Retreat, December 17-18, 2018, Monterey, CA.
Shift in accumulation of flavonoids and phenolic acids in lettuce attributable to changes in ultraviolet radiation and temperature Reprint Icon - (Peer Reviewed Journal)
Sytar, O., Zivcak, M., Bruckova, K., Brestic, M., Olsovska, K., Hemmerich, I., Rauh, C., Simko, I. 2018. Shift in accumulation of flavonoids and phenolic acids in lettuce attributable to changes in ultraviolet radiation and temperature. Scientia Horticulturae. 239:193–204. https://doi.org/10.1016/j.scienta.2018.05.020.
Understanding salt tolerance in lettuce - (Abstract Only)
Adhikari, N.D., Whitten, D., Soria, A., Simko, I., Mou, B. 2018. Understanding salt tolerance in lettuce. American Society of Horticultural Science Annual Meeting, July 31-August 3, 2018, Washington, DC.
Accuracy, reliability, and timing of visual evaluations of decay in fresh-cut lettuce Reprint Icon - (Peer Reviewed Journal)
Simko, I., Hayes, R.J. 2018. Accuracy, reliability, and timing of visual evaluations of decay in fresh-cut lettuce. PLoS One. 13(4):e0194635. https://doi.org/10.1371/journal.pone.0194635.
Lettuce and spinach breeding ()
Simko, I., Mou, B., McCreight, J.D. 2018. Lettuce and spinach breeding. California Leafy Greens Research Program Annual Meeting, March 27, 2018, Pismo Beach, California.
Genome-wide association mapping of loci for the rate of deterioration in fresh-cut lettuce - (Abstract Only)
Sthapit, J., Mou, B., Hayes, R.J., Simko, I. 2018. Genome-wide association mapping of loci for the rate of deterioration in fresh-cut lettuce. American Society of Plant Biologists Annual Meeting, July 14-18, 2018, Montreal, Canada.
Genome-wide association mapping of deterioration in fresh-cut lettuce - (Abstract Only)
Sthapit, J., Mou, B., Simko, I., Hayes, R.J. 2018. Genome-wide association mapping of deterioration in fresh-cut lettuce. American Society of Horticultural Science Annual Meeting, July 31-August 3, 2018, Washington, DC.
Novel sources of resistance to Florida isolates of Bacterial leaf spot in lettuce (Lactuca sativa L.) - (Abstract Only)
Sandoya, G.V., Wadlington, W., Raid, R.N., Simko, I., Bull, C.T. 2018. Novel sources of resistance to Florida isolates of Bacterial leaf spot in lettuce (Lactuca sativa L.). American Society of Horticultural Science Annual Meeting, July 31-August 3, 2018, Washington, DC.
LsGA2ox2 regulates lettuce seed germination under darkness - (Abstract Only)
Huo, H., Niroula, M., Hill, T., Li, J., Nguyen, C., Truco, M.J., Simko, I., Michelmore, R.W., Bradford, K. 2018. LsGA2ox2 regulates lettuce seed germination under darkness. American Society of Horticultural Science Annual Meeting, July 31-August 3, 2018, Washington, DC.
Molecular markers reliably predict post-harvest decay of fresh-cut lettuce in modified atmosphere packaging Reprint Icon - (Peer Reviewed Journal)
Simko, I., Hayes, R.J., Truco, M., Michelmore, R.W., Antonise, R., Massoudi, M. 2018. Molecular markers reliably predict post-harvest decay of fresh-cut lettuce in modified atmosphere packaging. Horticulture Research. 5:21. https://doi.org/10.1038/s41438-018-0022-5.
PCR assay for Verticillium dahliae race 1 resistance in lettuce based on genome sequencing of 61 accessions - (Abstract Only)
Inderbitzin, P., Reyes-Chin Wo, S., Christopoulou, M., Michelmore, R.W., Subbarao, K.V., Simko, I. 2018. PCR assay for Verticillium dahliae race 1 resistance in lettuce based on genome sequencing of 61 accessions. International Congress of Plant Pathology, July 29-August 3, 2018, Boston, Massachusetts.
Characterization of resistance to lettuce drop, and its association with plant architecture and composition in lettuce - (Abstract Only)
Mamo, B.E., Adhikari, N.D., Foster, C., Zucker, L., Hayes, R.J., Subbarao, K.V., Simko, I. 2018. Characterization of resistance to lettuce drop, and its association with plant architecture and composition in lettuce. International Congress of Plant Pathology, July 29-August 3, 2018, Boston, Massachusetts.
Release of three iceberg lettuce populations that combined resistance to two soil borne diseases Reprint Icon - (Peer Reviewed Journal)
Hayes, R.J., Sandoya, G., Mou, B., Simko, I., Subbarao, K.V. 2018. Release of three iceberg lettuce populations that combined resistance to two soil borne diseases. HortScience. 53(2):247-250. https://doi.org/10.21273/HORTSCI12559-17.
Post-harvest decay in fresh-cut lettuce ()
Simko, I. 2017. Post-harvest decay in fresh-cut lettuce. NIFA-SCRI Annual Project Meeting of Principle Investigators. October 20, 2017, Davis, California.
Lettuce and spinach breeding ()
Simko, I., McCreight, J.D., Mou, B. 2017. Lettuce and spinach breeding. California Leafy Greens Research Program Annual Meeting. October 10, 2017, Salinas, California.
Variation within lactuca spp. for resistance to impatiens necrotic spot virus Reprint Icon - (Peer Reviewed Journal)
Simko, I., Richardson, C.E., Wintermantel, W.M. 2018. Variation within lactuca spp. for resistance to impatiens necrotic spot virus. Plant Disease. 102(2):341-348. https://doi.org/10.1094/PDIS-06-17-0790-RE.
Finding the fighters. Maturity-adjusted resistance of potato cultivars to Verticillium wilt Reprint Icon ()
Simko, I., Haynes, K.G. 2017. Finding the fighters. Maturity-adjusted resistance of potato cultivars to Verticillium wilt. Potato Grower. 46:38-39.
Breeding and genetics of lettuce for resistance against race 2 Verticillium wilt - (Abstract Only)
Sandoya, G.V., Truco, M.J., Subbarao, K.V., Martin, F.N., Michelmore, R.M., Hayes, R.J., Simko, I. 2017. Breeding and genetics of lettuce for resistance against race 2 Verticillium wilt. National Association of Plant Breeders Annual Meeting, August 7-10, 2017, Davis, California.
Lettuce breeding ()
Simko, I., Mou, B., McCreight, J.D. 2017. Lettuce breeding. California Leafy Greens Research Board. Available: http://calgreens.org/wp-content/uploads/2016/06/Lettuce-Breeding-USDA-ARS-Simko-Mou-and-McCreight.pdf.
Genome-wide association study for lettuce cultivars with improved salad processing efficiency - (Abstract Only)
Sthapit, J.K., Mou, B., Simko, I., Hayes, R.J. 2017. Genome-wide association study for lettuce cultivars with improved salad processing efficiency. American Society for Horticultural Science Annual Meeting, September 19-22, 2017, Waikoloa, Hawaii.
Characterization of Verticillium dahliae disease reactions in lettuce differential cultivars - (Abstract Only)
Short, D.P.G., Puri, K., Sandoya, G.V., Simko, I., Hayes, R.J., Subbarao, K.V. 2017. Characterization of Verticillium dahliae disease reactions in lettuce differential cultivars. American Phytopathological Society Annual Meeting, August 5-9, 2017, San Antonio, Texas.
Genetic characterization of resistance to Sclerotinia in lettuce cultivar Eruption - (Abstract Only)
Mamo, B.E., Hayes, R.J., Truco, M.J., Michelmore, R., Subbarao, K.V., Simko, I. 2017. Genetic characterization of resistance to Sclerotinia in lettuce cultivar Eruption. American Phytopathological Society Annual Meeting, August 5-9, 2017, San Antonio, Texas.
Lettuce and spinach breeding - (Abstract Only)
Simko, I., McCreight, J.D., Mou, B. 2017. Lettuce and spinach breeding. California Leafy Greens Research Program Annual Meeting. March 14, 2017, Pismo Beach, California.
Nondestructive phenotyping of lettuce plants in early stages of development with optical sensors - (Peer Reviewed Journal)
Simko, I., Hayes, R.J., Furbank, R.T. 2016. Nondestructive phenotyping of lettuce plants in early stages of development with optical sensors. Frontiers in Plant Science. 7:1-19.
Maturity-adjusted resistance of potato (Solanum tuberosum L.) cultivars to Verticillium wilt caused by Verticillium dahliae - (Peer Reviewed Journal)
Simko, I., Haynes, K.G. 2017. Maturity-adjusted resistance of potato (Solanum tuberosum L.) cultivars to Verticillium wilt caused by Verticillium dahliae. American Journal of Potato Research. 94:173–177.
Advancements in utilizing molecular markers in lettuce breeding - (Proceedings)
Simko, I. 2017. Advancements in utilizing molecular markers in lettuce breeding. 4th International Symposium on Molecular Markers in Horticulture, International Society for Horticultural Science. March 7-10, 2017, Napier, New Zealand.
Lettuce and spinach breeding - (Proceedings)
Simko, I., McCreight, J.D., Mou, B., Klosterman, S.J. 2016. Lettuce and spinach breeding. California Leafy Greens Research Program Mid-Year Meeting. October 4, 2016, Salinas, California.
Phenomic approaches and tools for phytopathologists - (Peer Reviewed Journal)
Simko, I., Jimenez-Berni, J.A., Sirault, X.R.R. 2016. Phenomic approaches and tools for phytopathologists. Phytopathology. 107:6-17.
Genetics of the partial resistance against race 2 of Verticillium dahliae in lettuce - (Proceedings)
Sandoya, G.V., Truco, M., Bertier, L., Subbarao, K.V., Michelmore, R., Simko, I., Hayes, R.J. 2016. Genetics of the partial resistance against race 2 of Verticillium dahliae in lettuce. American Society for Horticultural Science Annual Meeting. Available: https://ashs.confex.com/ashs/2016/webprogram/Paper24442.html.
Lettuce and spinach breeding - (Proceedings)
Simko, I., Hayes, R.J., Mou, B., McCreight, J.D. 2016. Lettuce breeding. California Leafy Greens Research Board Annual Meeting. Available: http://calgreens.org/wp-content/uploads/2016/06/Lettuce-Breeding-USDA-ARS-Simko-Mou-and-McCreight.pdf.
Genetic characterization of quantitative resistance to Bremia lactucae, the causal organism of lettuce downy mildew - (Proceedings)
Parra, L., Simko, I., Michelmore, R. 2016. Genetic characterization of quantitative resistance to Bremia lactucae, the causal organism of lettuce downy mildew. American Phytopathological Society Annual Meeting. Available: http://www.apsnet.org/meetings/annual/abstracts/pages/abstractdetail.aspx?MID=550.
Breeding lettuce for improved fresh-cut processing - (Peer Reviewed Journal)
Hayes, R.J., Simko, I. 2016. Breeding lettuce for improved fresh-cut processing. Acta Horticulturae. 1141:65-76. doi: 10.17660/ActaHortic.2016.1141.7.
High-resolution DNA melting analysis in plant research - (Peer Reviewed Journal)
Simko, I. 2016. High-resolution DNA melting analysis in plant research. Trends in Plant Science. 21(6):528-537.
Genetics of resistance against lettuce downy mildew - (Proceedings)
Parra, L., Ochoa, O.E., Mchale, L.K., Christopoulou, M., Simko, I., Michelmore, R. 2016. Genetics of resistance against lettuce downy mildew. Plant and Animal Genome Conference Proceedings. Available: https://pag.confex.com/pag/xxiv/webprogram/Paper19545.html.
Assessing genetic variation in lettuce for traits related to nitrogen use efficiency using susceptibility and relative efficiency indices - (Proceedings)
Gonzalez, M.M., Truco, M., Michelmore, R., Smith, R., Cahn, M., Simko, I., Hayes, R.J. 2015. Assessing genetic variation in lettuce for traits related to nitrogen use efficiency using susceptibility and relative efficiency indices. ASA, CSSA, and SSSA Annual Meeting. Available: https://scisoc.confex.com/scisoc/2015am/webprogram/Paper93179.html.
Comparing the predictive abilities of phenotypic and marker-assisted selection methods in a biparental lettuce population Reprint Icon - (Peer Reviewed Journal)
Hadasch, S., Simko, I., Hayes, R.J., Ogutu, J.O., Piepho, H.-P. 2016. Comparing the predictive abilities of phenotypic and marker-assisted selection methods in a biparental lettuce population. The Plant Genome. 9(1):1-11.
Application of chlorophyll fluorescence imaging and hyperspectral imaging in evaluation of decay in fresh-cut lettuce - (Abstract Only)
Simko, I., Jimenez-Berni, J.A., Furbank, R.T. 2015. Application of chlorophyll fluorescence imaging and hyperspectral imaging in evaluation of decay in fresh-cut lettuce. International Plant and Algal Phenomics Meeting, June 27-30, 2015, Prague, Czech Republic.
Breeding lettuce for fresh-cut processing - (Abstract Only)
Hayes, R.J., Simko, I. 2015. Breeding lettuce for fresh-cut processing. III International Conference on Fresh-cut Produce: Maintaining Quality and Safety, September 13-18, 2015, Davis, California.
Analysis of bibliometric indicators to determine citation bias - (Peer Reviewed Journal)
Simko, I. 2015. Analysis of bibliometric indicators to determine citation bias. Palgrave Communications. doi: 10.1057/palcomms.2015.11.
Resistance to downy mildew in lettuce ‘La Brillante’ is conferred by dm50 gene and multiple QTL - (Peer Reviewed Journal)
Simko, I., Ochoa, O.E., Pel, M.A., Tsuchida, C., Forcada, C.F., Hayes, R.J., Truco, M.J., Antonise, R., Galeano, C.H., Michelmore, R.W. 2015. Resistance to downy mildew in lettuce ‘La Brillante’ is conferred by dm50 gene and multiple QTL. Phytopathology. 105:1220-1228.
Detection of decay in fresh-cut lettuce using hyperspectral imaging and chlorophyll fluorescence imaging - (Peer Reviewed Journal)
Simko, I., Jimenez-Berni, J.A., Furbank, R.T. 2015. Detection of decay in fresh-cut lettuce using hyperspectral imaging and chlorophyll fluorescence imaging. Postharvest Biology and Technology. 106:44–52.
Downy mildew disease promotes the colonization of romaine lettuce by Escherichia coli O157:H7 and Salmonella enterica Reprint Icon - (Peer Reviewed Journal)
Simko, I., Zhou, Y., Brandl, M. 2015. Downy mildew disease promotes the colonization of romaine lettuce by Escherichia coli O157:H7 and Salmonella enterica. BMC Microbiology. 15:19. doi: 10.1186/s12866-015-0360-5.
Inheritance of decay of salad-cut lettuce in a recombinant inbred line population from ‘Salinas 88’ x ‘La Brillante’ - (Peer Reviewed Journal)
Hayes, R.J., Galeano, C.H., Luo, Y., Antonise, R., Simko, I. 2014. Inheritance of decay of salad-cut lettuce in a recombinant inbred line population from ‘Salinas 88’ x ‘La Brillante’. Journal of the American Society for Horticultural Science. 139:388-398.
Characterization and performance of 16 new inbred lines of lettuce Reprint Icon - (Peer Reviewed Journal)
Simko, I., Hayes, R.J., Bull, C.T., Mou, B., Luo, Y., Trent, M.A., Atallah, A.J., Ryder, E.J., Sideman, R.G. 2014. Characterization and performance of 16 new inbred lines of lettuce. HortScience. 49:679-687.
Notice of release of iceberg, romaine, and leaf lettuce breeding lines with improved disease resistance ()
Simko, I., Hayes, R.J. 2014. Notice of release of iceberg, romaine, and leaf lettuce breeding lines with improved disease resistance. Germplasm Release. Available: http://calgreens.org/wp-content/uploads/2014/03/USDA-Releases-Sixteen-New-Breeding-LInes-of-Lettuce1.pdf.
QTL mapping, association mapping and marker assisted breeding in lettuce - (Proceedings)
Simko, I. 2014. QTL mapping, association mapping and marker assisted breeding in lettuce. American Seed Trade Association Conference, January 23-27, 2014, Monterey, California. Available: http://biodiagnostics.net/wp-content/uploads/2014/04/Dr.-Simko-ASTA-on-Lettuce-breeding-strategies-2014.pdf.
Development of a high-density intra-specific linkage map of lettuce using genotyping by sequencing (GBS) - (Proceedings)
Galeano, C.H., Froenicke, L., Duitama, J., Kozik, A., Reyes-Chin-Wo, S., Simko, I., Hayes, R.J., Michelmore, R. 2014. Development of a high-density intra-specific linkage map of lettuce using genotyping by sequencing (GBS). Plant and Animal Genome XXII Conference, January 11-15, 2014, San Diego, California. P686.
Baby leaf lettuce germplasm enhancement: developing diverse populations with resistance to bacterial leaf spot caused by Xanthomonas campestris pv. vitians - (Peer Reviewed Journal)
Hayes, R.J., Trent, M.A., Mou, B., Simko, I., Gebben, S.J., Bull, C.T. 2014. Baby leaf lettuce germplasm enhancement: developing diverse populations with resistance to bacterial leaf spot caused by Xanthomonas campestris pv. vitians. HortScience. 49:18–24.
Identification of QTLs conferring resistance to downy mildew in legacy cultivars of lettuce - (Peer Reviewed Journal)
Simko, I., Atallah, A.J., Ochoa, O., Antonise, R., Galeano, C., Truco, M.J., Michelmore, R. 2013. Identification of QTLs conferring resistance to downy mildew in legacy cultivars of lettuce. Scientific Reports. DOI:10.1038/srep02875.
Genome-wide association of 10 horticultural traits with expressed sequence tag-derived SNP markers in a collection of lettuce lines Reprint Icon - (Peer Reviewed Journal)
Kwon, S.J., Simko, I., Hellier, B.C., Mou, B., Hu, J. 2013. Genome-wide association of 10 horticultural traits with expressed sequence tag-derived SNP markers in a collection of lettuce lines. The Crop Journal. 1(1):25-33. DOI: 10.1016/j.cj.2013.07.014.
Yield gains in leafy vegetables ()
Simko, I., Hayes, R.J., Mou, B., McCreight, J.D. 2014. Yield gains in leafy vegetables. In: Smith, S., Diers, B., Specht, J., Carver, B., editors. Yield gains in major U.S. field crops. CSSA Special Publications 33. Madison, WI: American Society of Agronomy, Inc., Crop Science Society of America, Inc., and Soil Science Society of America, Inc. p. 53-86.
Evaluation and Quantitative trait loci mapping of resistance to powdery mildew in lettuce - (Peer Reviewed Journal)
Simko, I., Rauscher, G., Sidemann, R., McCreight, J.D., Hayes, R.J. 2013. Evaluation and Quantitative trait loci mapping of resistance to powdery mildew in lettuce. Plant Pathology. DOI: 10.1111/ppa.12087.
Development of genomic SSR markers for fingerprinting lettuce (Lactuca sativa L.) cultivars and mapping genes - (Peer Reviewed Journal)
Rauscher, G., Simko, I. 2013. Development of genomic SSR markers for fingerprinting lettuce (Lactuca sativa L.) cultivars and mapping genes. BMC Plant Biology. 13:11.
Marker-assisted selection for disease resistance in lettuce ()
Simko, I. 2013. Marker-assisted selection for disease resistance in lettuce. In: Varshney, R.K., Tuberosa, R., editors. Translational genomics for crop breeding. Vol. I: Biotic stresses. Ames, IA: John Wiley & Sons, Inc. p. 267-289.
AUDPC and AUDPS: What is the Difference? - (Abstract Only)
Simko, I., Piepho, H. 2012. AUDPC and AUDPS: What is the Difference? Phytopathology. 102:S4.110.
Environmental factors contributing to development of lettuce dieback disease and genomic characterization of lettuce necrotic stunt virus - (Abstract Only)
Wintermantel, W.M., Simko, I. 2012. Environmental factors contributing to development of lettuce dieback disease and genomic characterization of lettuce necrotic stunt virus. Phytopathology. 102:S4.136.
Computing Integrated Ratings from Heterogeneous Phenotypic Assessments: A Case Study of Lettuce Postharvest Quality and Downy Mildew Resistance - (Peer Reviewed Journal)
Simko, I., Hayes, R.J., Kramer, M.H. 2012. Computing integrated ratings from heterogeneous phenotypic assessments: A case study of lettuce postharvest quality and downy mildew resistance. Crop Science. 52:2131-2142.
Empirical evaluation of DArT, SNP, and SSR marker-systems for genotyping, clustering, and assigning sugar beet hybrid varieties into populations - (Peer Reviewed Journal)
Simko, I., Eujayl, I.A., Van Hintum, Jl, T. 2012. Empirical evaluation of DArT, SNP, and SSR marker-systems for genotyping, clustering, and assigning sugar beet hybrid varieties into populations. Plant Science. 184:54-62.
The area under the disease progress stairs: calculation, advantage, and application - (Peer Reviewed Journal)
Simko, I., Piepho, H. 2012. The area under the disease progress stairs: calculation, advantage, and application. Phytopathology. 102:381-389.
Developing lettuce with improved quality for processed salads. - (Abstract Only)
Hayes, R.J., Truco, M.J., Mchale, L.K., Michelmore, R.W., Antonise, R., Hand, P., Simko, I. 2011. Developing lettuce with improved quality for processed salads. Eucarpia Conference on Lettuce and Leafy Vegetables. August 24, 2011, Lille, France.
Mapping dominant negative mutation for triforine sensitivity in lettuce and its use as a selectable marker for detecting hybrids. - (Peer Reviewed Journal)
Simko, I., Hayes, R.J., Truco, M.J., Michelmore, R.W. 2011. Mapping dominant negative mutation for triforine sensitivity in lettuce and its use as a selectable marker for detecting hybrids. Euphytica. 182(2):157-166.
Combining phenotypic data from ordinal rating scales in multiple plant experiments - (Peer Reviewed Journal)
Simko, I., Piepho, H. 2011. Combining phenotypic data from ordinal rating scales in multiple plant experiments. Trends in Plant Science. 16:235-237.
Application of Hi-Res Melting Approach for Mapping Resistance Genes and Marker-assisted Selection in Lettuce ()
Simko, I. 2011. Application of Hi-Res Melting Approach for Mapping Resistance Genes and Marker-assisted Selection in Lettuce. Plant and Animal Genome Conference. Online.
Iceberg lettuce breeding lines with resistance to Verticillium wilt caused by race 1 isolates of Verticillium dahliae. - (Peer Reviewed Journal)
Hayes, R.J., Maruthachalam, K., Vallad, G.E., Klosterman, S.J., Simko, I., Luo, Y., Subbarao, K.V. 2011. Iceberg lettuce breeding lines with resistance to Verticillium wilt caused by race 1 isolates of Verticillium dahliae. HortScience. 46(3):501-504.
Evaluation of the RPi-ber late blight resistance gene for tuber resistance in the field and laboratory. - (Peer Reviewed Journal)
Mayton, H., Rauscher, G., Simko, I., Fry, W. 2011. Evaluation of the RPi-ber late blight resistance gene for tuber resistance in the field and laboratory. Plant Breeding. 130:464-468.
Combining partially ranked data in plant breeding and biology: II. Analysis with Rasch model. - (Peer Reviewed Journal)
Simko, I., Lincare, J.M. 2010. Combining partially ranked data in plant breeding and biology: II. Analysis with Rasch model.. Communications in Biometry and Crop Science (CBCS). 2010, Vol 5, Pages 56-65.
Combining partially ranked data in plant breeding and biology: I. Rank aggregating methods. - (Peer Reviewed Journal)
Simko, I., Pechenick, D.A. 2010. Combining partially ranked data in plant breeding and biology: I. Rank aggregating methods.. Communications in Biometry and Crop Science (CBCS), Year 2010, volume 5, pages 41-55.
SM09A and SM09B: Romaine Lettuce Breeding Lines Resistant to Dieback and with Improved Shelf-life. - (Peer Reviewed Journal)
Simko, I., Hayes, R.J., Subbarao, K.V., Sideman, R.G. 2010. SM09A and SM09B: Romaine Lettuce Breeding Lines Resistant to Dieback and with Improved Shelf-life.. HortScience,Year 2010, volume 45, pages 670-672.
Association mapping and marker-assisted selection of the lettuce dieback resistance gene Tvr1. - (Peer Reviewed Journal)
Simko, I., Pechenick, D.A., Mchale, L.K., Truco, M.J., Ochoa, O.E., Michelmore, R.W., Scheffler, B.E. 2009. Association mapping and marker-assisted selection of the lettuce dieback resistance gene Tvr1.. Biomed Central (BMC) Plant Biology, Year 2009, volume 9, article number 135.
Development of molecular markers for marker-assisted selection in lettuce (Lactuca sativa). - (Peer Reviewed Journal)
Simko, I., Pechenick, D.A., Mchale, L.K., Truco, M.J., Ochoa, O.E., Michelmore, R.W., Scheffler, B.E. 2010. Development of molecular markers for marker-assisted selection in lettuce (Lactuca sativa). Acta Horticulture Proceedings, Year 2010, volume 859, pages 401-408.
QTL mapping of resistance to Powdery Mildew in lettuce. - (Abstract Only)
Rauscher, G.M., Hayes, R.J., Simko, I. 2009. QTL mapping of resistance to Powdery Mildew in lettuce. Phytopathology 99:S107.
Development of molecular markers for marker-assisted selection in lettuce (Lactuca sativa). - (Abstract Only)
FOLIAR AND TUBER BLIGHT RESISTANCE IN A SOLANUM TUBEROSUM BREEDING LINES. ()
Mayton, H., Griffiths, H., Simko, I., Cheng, S., Lorenzen, J., De Jong, W., Fry, W.E. 2009. FOLIAR AND TUBER BLIGHT RESISTANCE IN A SOLANUM TUBEROSUM BREEDING LINES.. Plant Breeding.DOI:10.1111/J.1439-0523.01671.x
Association analysis of beet curly top disease resistant genes in sugarbeet - (Abstract Only)
Eujayl, I.A., Simko, I., Strausbaugh, C.A. 2009. Association analysis of beet curly top disease resistant genes in sugarbeet [Abstract]. Proceedings of 35th Biennial Meeting of American Society of Sugar Beet Technologists: Section B&E. Paper No. 1.
Development of EST-SSR Markers for the Study of Population Structure in Lettuce (Lacutca sativa L.). - (Peer Reviewed Journal)
Simko, I. 2009. Development of EST-SSR Markers for the Study of Population Structure in Lettuce (Lacutca sativa L.). Journal of Heredity 180: 256-262.
Effect of Isolate, Environment and a Defeated R-gene (RPi-ber) on Quantitative Resistance of Potato to Late Blight - (Peer Reviewed Journal)
Rauscher, G.M., Mayton, H., Bonierbale, M., Simko, I., Smart, C., Grunwald, N.J., Fry, W. Effect of Isolate, Environment and a Defeated R-gene (RPi-ber) on Quantitative Resistance of Potato to Late Blight. American Phytopathological Society Annual Meeting, Minneapolis, Minnesota, July 26-July 30. Phytopathology 98:S130.
MAPPING LOCI FOR CHLOROSIS ASSOCIATED WITH CHLOROPHYLL B DEFICIENCY IN POTATO - (Peer Reviewed Journal)
Simko, I., Van Den Berg, J.H., Vreugdenhil, D., Ewing, E.E. 2008. Mapping loci for chlorosis associated with chlorophyll b deficiency in potato. Euphytica Vol 162, Pages 99-107, 2008.
Populations structure in cultivated lettuce (Lactuca sativa L.) and its impact on assocation mapping. - (Peer Reviewed Journal)
Simko, I., Hu, J. Populations structure in cultivated lettuce (Lactuca sativa L.) Journal of the American Society for Horticultural Science, Vol. 133, Pages 61-68, 2008.
Comparison of the two pathogenic systems: Bremia Lactucae on Lactuca, and Phytophthora infestans on Solarum - (Abstract Only)
Simko, I. 2007. Comparison of the two pathogenic systems: Bremia Lactucae on Lactuca, and Phytophthora infestans on Solarum. Downy Mildews 2nd International Symposium. Olomouc, Czech Republic, July 2-7, 2007.
From Association Mapping to Marker-Assisted Selection: Experimental Design and Application. - (Abstract Only)
Simko, I. 2007. From Association Mapping to Marker-Assisted Selection: Experimental Design and Application. Phytopathology 97:S149..
Effect of Population Structure on Association Mapping in Cultivated Lettuce. - (Abstract Only)
Simko, I., Hu, J. 2007. Effect of Population Structure on Association Mapping in Cultivated Lettuce. In Eucarpia Leafy Vegetables 2007 Conference Abstracts. Warwick, UK, April 18-20, 2007.
Foliar and tuber late blight resistance in a Solanum tuberosum potato mapping population - (Abstract Only)
Mayton, H., Simko, I., Dejong, W., Fry, W. 2006. Foliar and tuber late blight resistance in a Solanum tuberosum potato mapping population. American Phytopathological Society Annual Meeting, Quebec City, Canada, July 29-August 2, 2006. Phytopathology 96:S74.
CHARACTERIZATION AND MAPPING OF RPI-BER, A NOVEL POTATO LATE BLIGHT RESISTANCE GENE FROM SOLANUM BERTHAULTII - (Peer Reviewed Journal)
Rancher, G., Smart, C.D., Simko, I., Bonierbale, M., Mayton, H., Greenland, A., Fry, W.E. 2006. Characterization and mapping of rpi-ber, a novel potato late blight resistance gene from solanum berthaultii. Theoretical and Applied Genetics. 112(4):674-687.
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