Source: KANSAS STATE UNIV submitted to
PLANT DISEASE RISK ASSESSMENT AND THE DEPLOYMENT OF AGRICULTURAL BIODIVERSITY
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
TERMINATED
Funding Source
Reporting Frequency
Annual
Accession No.
0208974
Grant No.
(N/A)
Project No.
KS373
Proposal No.
(N/A)
Multistate No.
(N/A)
Program Code
(N/A)
Project Start Date
Oct 1, 2006
Project End Date
Sep 30, 2012
Grant Year
(N/A)
Project Director
Garrett, K.
Recipient Organization
KANSAS STATE UNIV
(N/A)
MANHATTAN,KS 66506
Performing Department
PLANT PATHOLOGY
Non Technical Summary
Plant disease is an important limiting factor in agriculture and its role in natural systems is only now being fully appreciated. Karnal bunt has not been reported in Kansas, but its presence to the south and possible eventual detection in Kansas make a better understanding of its epidemiology critical to the trade negotiations that will be necessary to protect the export market for Kansas wheat. We are developing improved risk assessments for this pathogen in collaboration with scientists in India where the pathogen is native. Wheat streak mosaic virus (WSMV) has caused devastating epidemics in Kansas, yet the current recommendation for removal of all weeds and volunteer wheat from summer fields results in increased soil erosion and reduced habitat for wildlife that also are important to the Kansas economy. We are studying the trade-offs for management for WSMV to construct improved strategies. For most plant diseases, resistance genes are the best disease management strategy available. We are working to develop basic evolutionary ecology concepts to support better decision-making for durable resistance gene deployment in agricultural systems. In natural systems, we also are studying natural patterns of disease resistance in the dominant tallgrass prairie species, big bluestem, a plant of great interest to basic ecologists and biofueld proponents. We are also leading work to study gene expression in ecologically-important natural plant communities in order to understand their responses to disease and altered precipitation patterns in the Great Plains.
Animal Health Component
50%
Research Effort Categories
Basic
50%
Applied
50%
Developmental
(N/A)
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
20515491060100%
Knowledge Area
205 - Plant Management Systems;

Subject Of Investigation
1549 - Wheat, general/other;

Field Of Science
1060 - Biology (whole systems);
Goals / Objectives
Project 1. Disease risk assessment in agricultural systems a. Karnal bunt of wheat. i. Estimate size of Allee effect (density-dependent destabilizing reproduction that results in reduced invasive ability) for Karnal bunt in field experiments in India where the pathogen is native (yrs 1-2) b. Wheat streak mosaic virus (WSMV). i. Complete evaluation of tillage effects on volunteer wheat and vector dispersal from previous field studies (yrs 1-2) c. Strategies for durable deployment of resistance genes in agricultural landscapes. i. Clarify role of gene deployment strategies for durability of disease resistance in landscape ecology models (yrs 1-5) Project 2. Disease risk assessment in natural systems a. Epidemiology in tallgrass prairie. b. Determine the effects of environmental drivers on foliar plant disease in long-term field experiments at Konza Prairie Biological Station (yrs 1-2) b. Gene expression in tallgrass prairie grasses in response to multiple stressors. a. Determine gene expression in response to biotic and abiotic stressors, including simulated climate change (yrs 1-5)
Project Methods
Project 1. Disease risk assessment in agricultural systems Karnal bunt of wheat: Estimate size of Allee effect (density-dependent destabilizing reproduction that results in reduced invasive ability) for Karnal bunt using field experiments in India where the pathogen is native (yrs 1-2) Wheat streak mosaic virus (WSMV): Complete evaluation of tillage effects on volunteer wheat and vector dispersal using data from previous field studies (yrs 1-2) Strategies for durable deployment of resistance genes in agricultural landscapes: Clarify role of gene deployment strategies for durability of disease resistance using landscape ecology models (yrs 1-5) Project 2. Disease risk assessment in natural systemsEpidemiology in tallgrass prairie: Determine the effects of environmental drivers on foliar plant disease using long-term field experiments at Konza Prairie Biological Station (yrs 1-2) Gene expression in tallgrass prairie grasses in response to multiple stressors: Determine gene expression in response to biotic and abiotic stressors, including simulated climate change, using field and greenhouse experiments (yrs 1-5).

Progress 10/01/06 to 09/30/12

Outputs
OUTPUTS: We have completed several projects contributing to more efficient management of plant disease risk and the deployment of biodiversity. For example, Cox et al. (in press) evaluated the role of landscape structure and pathogen sharing in tallgrass prairie plants, many of which are being developed as biofuel crops and likely to be subject to greater disease pressure if produced in monocultures. Garrett (2012) evaluated research related to the role of information in systems for plant disease management. Gomez-Montano et al. (in revision) evaluated the effects of cropping system changes on microbial biodiversity. Sutrave et al. (2012) evaluated efficient choices for sampling epidemic invasions, using the US soybean rust data sets as an example. We have also contributed to training students in these approaches, for example in a new chapter on modeling plant disease (Garrett et al., in press). L. Gomez-Montano graduated this year with a M.S. studying agricultural biodiversity in the context of soil microbial communities and their responses to cropping system. Gomez-Montano also mentored an undergraduate student, T. Carrtar. PARTICIPANTS: These projects engaged students including the following: Xiuqin Bai, graduate student in Statistics Tennery Carrtar, undergraduate student Lorena Gomez-Montano, graduate student in Plant Pathology Girly Ramirez, graduate student in Statistics Bo Tong, graduate student in Statistics Lianqing Zheng, graduate student in Statistics Collaborators in other KSU departments include: Shawn Hutchinson, Geography Ari Jumpponen, Biology Bala Natarajan, ECE Caterina Scoglio, ECE Kim With, Biology Collaborators in other institutions include: Liz Borer, University of Minnesota Jorge Cusicanqui, Bolivia Andy Dobson, University of Oxford, UK Paul Esker, University of Wisconsin Greg Forbes, International Potato Center, China Miguel Angel Gonzales, FAO, Bolivia Bob Holt, University of Florida Scott Isard, Pennsylvania State University Jurgen Kroschel, International Potato Center, Peru Peter Motovalli, University of Missouri Simone Orlandini, University of Florence, Italy Adam Sparks, International Rice Research Institute, Philippines Henri Tonnang, International Potato Center, Peru Corinne Valdivia, University of Missouri Partner organizations include: Ceres Trust CGIAR Climate Change, Agriculture and Food Security program CGIAR Roots Tubers and Bananas program FAO International Food Policy Research Institute International Potato Center, Peru and China International Rice Research Institute Pennsylvania State University University of Florence, Italy University of Florida University of Minnesota University of Missouri University of Oxford University of Wisconsin TARGET AUDIENCES: We developed these projects to support US and international programs in improving plant disease management. We have engaged the international scientific community to increase the impact of the work. We have also provided training to students at KSU in research projects and through teaching a course in Ecology and Epidemiology of Plant Pathogens (PLPTH905). PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
We make it a priority to develop our outputs into publications. The outputs described above are published or in the process of being published. The new insights and models we have been developing have been deemed useful by CGIAR programs and the Ceres Trust and we have been awarded new research funds by both to strengthen this research.

Publications

  • Borer, E. T., J. Antonovics, L. L. Kinkel, P. J. Hudson, P. Daszak, M. J. Ferrari, K. A. Garrett, C. R. Parrish, A. F. Read, and D. M. Rizzo. 2011. Bridging taxonomic and disciplinary divides in infectious disease. EcoHealth 8:261-267 [published 2012].
  • Garrett, K. A. 2012. Information networks for plant disease: Commonalities in human management networks and within-host signaling networks. [Invited] European Journal of Plant Pathology 133:75-88.
  • Garrett, K. A., G. A. Forbes, L. Gomez, M. A. Gonzales, M. Gray, P. Skelsey, and A. H. Sparks. 2012. Cambio climatico, enfermedades de las plantas e insectos plaga. In Cambio climatico en los Andes. E. Jimenez, ed. (in press)
  • Garrett, K. A., A. Jumpponen, C. Toomajian, and L. Gomez-Montano. 2012. Climate change and plant health: Designing research spillover from plant genomics for understanding the role of microbial communities. [Invited] Canadian Journal of Plant Pathology 34:349-361.
  • Sutrave, S., C. Scoglio, S. A. Isard, J. M. S. Hutchinson, and K. A. Garrett. 2012. Identifying highly connected counties compensates for resource limitations when evaluating national spread of an invasive pathogen. PLoS ONE 7:e37793.


Progress 01/01/11 to 12/31/11

Outputs
OUTPUTS: The results of our project have been disseminated to stakeholders through the publications listed below, through presentations at national and international scientific meetings, and through presentations to policy makers. PARTICIPANTS: Over 50 collaborators worked on these projects, representing over 20 institutions. Among these, 12 participants were students or postdocs who were provided training as part of their participation in the projects. TARGET AUDIENCES: Our target audience was the scientific community, regulatory agencies such as APHIS and EPA, students, and agriculturalists working in cropping systems. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
Our work on plant disease risk in the context of global change provides benefits to agricultural research and extension personnel who have responsibility for formulating and explaining disease management strategies under changing circumstances. It also provides benefits to policy makers who must weigh plant disease risk factors along with other system components. As part of an international collaboration linking researchers in Latin America, Europe, Southeast Asia, and Pacific Asia, we have evaluated key components of climate change analyses that should be considered in planning for climate change adaptation. As part of a global analysis of potato late blight risk under climate change, we have developed a framework for applying disease risk models that require high resolution input in a broader range of scenarios. We have also contributed to a FAO analysis of microbial genetic resources to address climate change adaptation, a synthesis of CGIAR activities to address climate change, and an EPA scientific advisory panel evaluating adjustments to pesticide exposure modeling. Our work in risk analyses for plant disease and pest systems provides benefits to regulatory agencies such as USDA APHIS and others with responsibility for addressing invasive pathogens. We have evaluated the effects of climate variability on farmer decision making. Expanding our work to support sampling of invasive plant pathogens through the development of improved epidemic network sampling methods. Our work evaluating pathogens in tallgrass prairie and links with pathogens of agriculture provides benefits for the development of biofuels industries based on tallgrass prairie species through new information about the genetic basis for productivity under stressful environmental conditions. We have characterized the distribution of a resistance gene homolog in the dominant grass species of tallgrass prairie, big bluestem, a potential biofuels crop adapted to drought. Other cross-system synthesis includes an assessment of potential synergies from evaluation of plant and animal systems together. As part of our ongoing work in applying the R programming environment in plant disease ecology, we have written a new chapter to introduce students of epidemiology to the subject. Our recommendations and evaluations have been used by UN FAO, US EPA, the US National Climate Assessment, the IPCC, and the CGIAR. Our work with risk analyses provides benefits to Kansas and USDA APHIS groups with responsibility for managing invasive pathogens by providing predictions for the geographic spread of new pathogens and by indicating locations where there is the greatest potential for disrupting invasions. It provides benefits to policy makers by illustrating one of the costs of limiting subsidies to too small a number of crop species, so that the agricultural landscape is artificially homogeneous and provides higher risk of disease and pest invasions.

Publications

  • Savary, S., A. Nelson, A. H. Sparks, L. Willocquet, E. Duveiller, G. Mahuku, G. Forbes, K. A. Garrett, D. Hodson, J. Padgham, S. Pande, M. Sharma, J. Yuen, A. Djurle. 2011. International agricultural research tackling the effects of global and climate changes on plant diseases in the developing world. Plant Disease 95:1204-1216. (KAES no. 12-263-J)
  • Sparks, A. H., G. A. Forbes, R. J. Hijmans, and K. A. Garrett. 2011. A metamodeling framework for extending the application domain of process-based ecological models. Ecosphere 2:art90. (KAES no. 11-372-J)
  • Beed, F., A. Benedetti, G. Cardinali, S. Chakraborty, T. Dubois, K. Garrett and M. Halewood. 2011. Climate change and micro-organism genetic resources for food and agriculture: State of knowledge, risks and opportunities. Paper 57, Food and Agriculture Organization of the United Nations. Rome, Italy. (KAES no. 11-318-B)
  • Garrett, K. A., G. A. Forbes, S. Savary, P. Skelsey, A. H. Sparks, C. Valdivia, A. H. C. van Bruggen, L. Willocquet, A. Djurle, E. Duveiller, H. Eckersten, S. Pande, C. Vera Cruz, and J. Yuen. 2011. Complexity in climate change impacts: A framework for analysis of effects mediated by plant disease. Plant Pathology 60:15-30. (KAES no. 11-060-J)
  • Rouse, M. N., A. A. Saleh, A. Seck, K. H. Keeler, S. E. Travers, S. H. Hulbert, and K. A. Garrett. 2011. Genomic and resistance gene homolog diversity of the dominant tallgrass prairie species across the U.S. Great Plains precipitation gradient. PLoS ONE 6:e17641. doi:10.1371/journal.pone.0017641. (KAES no. 11-286-J)


Progress 01/01/10 to 12/31/10

Outputs
OUTPUTS: The results of our project have been disseminated to stakeholders through the publications listed below, through presentations at national and international scientific meetings, and through presentations to policy makers. PARTICIPANTS: Over 50 collaborators worked on these projects, representing over 20 institutions. Among these, 12 participants were students or postdocs who were provided training as part of their participation in the projects. TARGET AUDIENCES: Our target audience was the scientific community and agriculturalists working in cropping systems. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
We have developed analyses of plant disease risk in the context of global change. As part of an international collaboration linking researchers in Latin America, Europe, Southeast Asia, and Pacific Asia, we have evaluated key components of climate change analyses that should be considered in planning for climate change adaptation (Garrett et al., in press). We have demonstrated the effects of temperature on disease resistance genes and their potential contributions to the durability of resistance (Webb et al. 2010). As part of a global analysis of potato late blight risk under climate change, we have developed a framework for applying disease risk models that require high resolution input in a broader range of scenarios (Sparks et al., in review). We have developed integrated analyses of risk that incorporate the range of factors important for small-scale farmers (Perez et al. 2010). We have evaluated disease ecology in tallgrass prairie and potential spill-over between agricultural and natural systems (Saleh et al. 2010). We have also characterized the distribution of a resistance gene homolog in the dominant grass species of tallgrass prairie (Rouse et al., in review). In a paper that was the Journal of Ecology Editor's Choice for March 2010, we presented an analysis of variation in this dominant grass species in resonse to altered environmental conditions associated with climate change (Travers et al. 2010). We have interpreted risk factors involved in emerging plant diseases for a general audience (Garrett et al. 2010). We have published the first of a series of analyses of microbial communities using high-throughput sequencing techniques, in a comparison of soil communities and their response to tillage and crop rotation in Kansas (Yin et al. 2010). As part of our ongoing work in applying the R programming environment in plant disease ecology, we have reviewed a new text on the subject (Garrett 2010).

Publications

  • C. Perez, C. Nicklin, O. Dangles, S. Vanek, S. Sherwood, S. Halloy, K. Garrett, and G. Forbes. 2010. Climate change in the High Andes: Implications and adaptation strategies for small-scale farmers. The International Journal of Environmental, Cultural, Economic and Social Sustainability 6:71-88.
  • M. N. Rouse, A. A. Saleh, A. Seck, K. H. Keeler, S. E. Travers, S. H. Hulbert, and K. A. Garrett. 2010. Genomic and resistance gene homolog diversity of the dominant tallgrass prairie species, Andropogon gerardii, across the Central U.S. precipitation gradient. In review.
  • A. H. Sparks, G. A. Forbes, R. J. Hijmans, and K. A. Garrett. 2010. A metamodeling framework to expand the application range of ecological models. In review.
  • S. E. Travers, Z. Tang, D. Caragea, K. A. Garrett, S. H. Hulbert, J. E. Leach, J. Bai, A. Saleh, A. K. Knapp, P. A. Fay, J. Nippert, P. S. Schnable, and M. D. Smith. 2010. Variation in gene expression of Andropogon gerardii in response to altered environmental conditions associated with climate change. Journal of Ecology 98:374-383.
  • C. Yin, K. L. Jones, D. E. Peterson, K. A. Garrett, S. H. Hulbert, and T. C. Paulitz. 2010. Members of soil bacterial communities sensitive to tillage and crop rotation. Soil Biology & Biochemistry 42:2111-2118.
  • K. A. Garrett. 2010. Review of A Practical Guide to Ecological Modelling. Using R as a Simulation Platform by Soetaert and Herman. Quarterly Review of Biology, in press.
  • K. A. Garrett, A. Jumpponen, and L. Gomez Montano. 2010. Emerging plant diseases: What are our best strategies for management Pages 152-160 in Controversies in Science and Technology, Vol. 3, From Evolution to Energy. Editors E. L. Kleinman, J. A. Delborne, K. A. Cloud-Hansen, and J. Handelsman. Liebert Publishers, New Rochelle, New York.


Progress 01/01/09 to 12/31/09

Outputs
OUTPUTS: The results of our project have been disseminated to stakeholders through the publications listed below, through presentations at national and international scientific meetings, and through presentations to policy makers. PARTICIPANTS: Over 40 collaborators worked on these projects, representing over 18 institutions. Among these, 10 participants were students who were provided training as part of their participation in the projects. TARGET AUDIENCES: Our target audience was the scientific community and agriculturalists working in cropping systems. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
We have completed development of a conceptual framework for the analysis of plant disease in the context of ecosystem services (Cheatham et al. 2009). We have developed analyses of plant disease risk in the context of global change, including a presentation for the U.S. National Academies (Garrett et al. 2009a, Garrett et al. 2009b). We have evaluated the effects of functional diversity in hosts in the context of disease risk across a climatic gradient (Garrett et al. 2009c). We have demonstrated the effects of temperature on disease resistance genes and their potential contributions to the durability of resistance (Webb et al. 2009). We have evaluated the impact of host landscape structure on disease risk, including an evaluation of the connectivity of the American agricultural landscape (Garrett et al., accepted pending revision; Margosian et al. 2009). We have evaluated disease ecology in tallgrass prairie and potential spill-over between agricultural and natural systems (Worapong et al. 2009, Saleh et al. 2009). We have developed statistical applications for the analysis of plant gene expression data sets (Gadbury et al., in press). We have interpreted risk factors involved in emerging plant diseases for a general audience (Garrett et al., in press).

Publications

  • A. A. Saleh, H. U. Ahmed, T. C. Todd, S. E. Travers, K. A. Zeller, J. F. Leslie, and K. A. Garrett. 2010. Relatedness of Macrophomina phaseolina isolates from tallgrass prairie, maize, soybean, and sorghum. Molecular Ecology 19:79-91.
  • K. M. Webb, I. Ona, J. Bai, K. A. Garrett, T. Mew, C. M. Vera Cruz, and J. E. Leach. 2009. A benefit of high temperature: Increased effectiveness of a rice bacterial blight disease resistance gene. New Phytologist 185:568-576.
  • J. Worapong, S. P. Dendy, Z. Tang, D. J. Awl, and K. A. Garrett. 2009. Limiting temperatures for urediniospore germination are low in a systemic rust fungus of tallgrass prairie. Mycologia 101:390-394.
  • K. A. Garrett, A. Jumpponen, and L. Gomez. 2010. Emerging plant diseases: What are our best strategies for management Controversies in Science and Technology, in press.


Progress 01/01/08 to 12/31/08

Outputs
OUTPUTS: The results of our project have been disseminated to stakeholders through the publications listed below, through presentations at national and international scientific meetings, and through presentations to policy makers. PARTICIPANTS: Over 50 collaborators worked on these projects, representing over 20 institutions. Among these, over 15 participants were students who were provided training as part of their participation in the projects. TARGET AUDIENCES: Our target audience was the scientific community and agriculturalists working in cropping systems. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
We have developed a conceptual framework for the analysis of plant disease in the context of ecosystem services (Cheatham et al., accepted pending revision). We have developed analyses of plant disease risk in the context of global change, including a presentation for the U.S. National Academies (Chakraborty et al. 2008; Garrett 2008; Garrett and Cox 2008; Garrett et al., in press). We have evaluated the impact of host landscape structure on disease risk, including an evaluation of the connectivity of the American agricultural landscape (Garrett et al., accepted pending revision; Margosian et al., in press). We have evaluated disease ecology in tallgrass prairie (Han et al. 2008; Worapong et al., accepted pending revision). We have developed statistical applications for the analysis of plant gene expression data sets (Gadbury et al., in press). We have engaged students in plant pathology, horticulture, statistics, and mathematics in preparation of teaching modules that use the R programming environment (Esker et al. 2008; Sparks et al. 2008a; Sparks et al. 2008b).

Publications

  • S. Chakraborty, J. Luck, G. Hollaway, A. Freeman, R. Norton, K. A. Garrett, K. Percy, A. Hopkins, C. Davis, and D. F. Karnosky. 2008. Impacts of global change on diseases of agricultural crops and forest trees. CAB Reviews: Perspectives in Agriculture, Veterinary Science, Nutrition and Natural Resources 3, No. 054. http://www.cababstractsplus.org/cabreviews
  • K. A. Garrett. 2008. Climate change and plant disease risk. Pages 143-155 in Global Climate Change and Extreme Weather Events: Understanding the Contributions to Infectious Disease Emergence. National Academies Press, Washington, D.C.
  • K. A. Garrett and C. M. Cox. 2008. Applied biodiversity science: Managing emerging diseases in agriculture and linked natural systems using ecological principles. Pages 368-386 in Infectious Disease Ecology: Effects of Ecosystems on Disease and of Disease on Ecosystems. R. Ostfeld, F. Keesing, and V. Eviner, editors. Princeton University Press.
  • X. Han, S. P. Dendy, K. A. Garrett, L. Fang, and M. D. Smith. 2008. Comparison of damage to native and exotic tallgrass prairie plants by natural enemies. Plant Ecology 198:197-210.
  • A. H. Sparks, P. D. Esker, M. Bates, W. Dall'Acqua, Z. Guo, V. Segovia, S. D. Silwal, S. Tolos, and K. A. Garrett. 2008a. Ecology and epidemiology in R: Disease progress over time. The Plant Health Instructor. DOI:10.1094/PHI-A-2008-0129-02. Available at http://www.apsnet.org/education/AdvancedPlantPath/Topics/RModules/doc 1
  • A. H. Sparks, P. D. Esker, G. Antony, L. Campbell, E. E. Frank, L. Huebel, M. N. Rouse, B. Van Allen, and K. A. Garrett. 2008b. Ecology and epidemiology in R: Spatial pattern analysis. The Plant Health Instructor. DOI:10.1094/PHI-A-2008-0129-03. Available at http://www.apsnet.org/education/AdvancedPlantPath/Topics/RModules/doc 3
  • P. D. Esker, A. H. Sparks, L. Campbell, Z. Guo, M. N. Rouse, S. D. Silwal, S. Tolos, B. Van Allen, and K. A. Garrett. 2008. Ecology and epidemiology in R: Disease forecasting and validation. The Plant Health Instructor. DOI:10.1094/PHI-A-2008-0129-01. Available at http://www.apsnet.org/education/AdvancedPlantPath/Topics/RModules/doc 4
  • In Press, 2008. M. R. Cheatham, M. N. Rouse, P. D. Esker, S. Ignacio, W. Pradel, R. Raymundo, A. H. Sparks, G. A. Forbes, T. R. Gordon, and K. A. Garrett. Beyond yield: Plant disease in the context of ecosystem services. Phytopathology.
  • In Press, 2008. K. A. Garrett, L. N. Zuniga, E. Roncal, G. A. Forbes, C. C. Mundt, Z. Su, and R. J. Nelson. The effects of host biodiversity on disease across a climatic gradient. Ecological Applications.
  • In Press, 2008. J. Worapong, S. P. Dendy, Z. Tang, D. J. Awl, and K. A. Garrett. Limiting temperatures for urediniospore germination are low in a systemic rust fungus of tallgrass prairie. Mycologia.
  • In press, 2008. G. A. Forbes, N. J. Grunwald, E. S. G. Mizubuti, J. L. Andrade-Piedra, and K. A. Garrett. 2008. Potato late blight in developing countries. Chapter in Current Concepts in Potato Disease Management. R. D. Peters, editor.
  • In press, 2008. G. L. Gadbury, K. A. Garrett, and D. B. Allison. Challenges and approaches to statistical design and inference in high dimensional investigations. In D. A. Belostotsky (Ed.) Plant Systems Biology, Methods in Molecular Biology Series. Totowa NJ: The Humana Press Inc.
  • In press, 2008. K. A. Garrett, M. Nita, E. D. De Wolf, L. Gomez, and A. H. Sparks. Plant pathogens as indicators of climate change. For Climate and Global Change: Observed Impacts on Planet Earth. T. Letcher, editor.
  • In press, 2008. M. L. Margosian, K. A. Garrett, J. M. S. Hutchinson, and K. A. With. Connectivity of the American agricultural landscape: Assessing the national risk of crop pest and disease spread. BioScience.


Progress 01/01/07 to 12/31/07

Outputs
OUTPUTS: Project 1. Disease risk assessment in agricultural systems a. Karnel bunt of wheat. We have developed new methods for analyzing an Allee effect (density-dependent destabilizing reproduction that results in reduced invasive ability) in microbial populations. We are currently applying these methods to analyze the response of the Karnal bunt pathogen using data sets we have developed through collaborative projects in India. b. Wheat streak mosaic virus (WSMV). We are completing analyses of the availability of volunteer wheat and other hosts, as reservoirs of this pathogen and its vector. c. Strategies for durable deployment of resistance genes in agricultural landscapes. We are modeling the effects of a set of gene deployment strategies for durability of disease resistance in landscape ecology models. d. Climate change and plant disease risk. We have further evaluated the effects of climate on plant disease risk, including how it impacts disease management approaches that rely on reduced within-field inoculum production (Garrett et al., in review). e. Wheat disease resistance. We have evaluated sample size requirements for confident estimation of wheat disease phenotypes (Bockus et al. 2007). f. Training modules for epidemiology. We have prepared a series of training modules for use of modern shareware for epidemiological analysis (Esker et al. 2007, Garrett et al. 2007, Sparks et al. 2007). Even before publication, these have gained a global audience. Project 2. Disease risk assessment in natural systems a. Epidemiology in tallgrass prairie. We are finalizing a long-term analysis of plant community epidemiology at Konza Prairie Biological Station. We have identified susceptibility in several prairie species to the wheat take-all pathogen (Cox et al., in review). A common rust fungus of tallgrass prairie has such a low temperature threshold for germination that its phenology may be strongly affected by climate change (Worapong et al., in review). We have found that invasive species in tallgrass prairie had lower pathogen pressure, consistent with the enemy release hypothesis (Han et al., in review). b. Gene expression in tallgrass prairie grasses in response to multiple stressors. We have developed methods to detect significant changes in gene expression in natural populations of dominant tallgrass prairie plant species (Travers et al. 2007). We have also developed and evaluated new experimental designs for application of two-color microarrays in more complex field experiments contexts (Milliken et al. 2007). We have also evaluted tallgrass prairie grass responses to drought and pathogen stress, linking transcriptomic responses to changes in phytohormone concentrations (Frank thesis, 2007). c. Genetic footprint of disease in populations of prairie grasses. We have provided evidence for disease selection pressures in tallgrass prairie grasses across Kansas and Missouri using a novel approach to draw inference from patterns of resistance gene homolog diversity (Rouse thesis, 2007). PARTICIPANTS: KSU: G. Antony, J. Bai, M. Bates, W. Bockus, R. Bowden, L. Campbell, C. Cox, W. Dall' Acqua, S. Dendy, P. Esker, L. Fang, E. Frank, A. Fritz, K. Garrett, B. Gill, Z. Guo, L. Huebel, T. J. Martin, G. Milliken, J. Roe, M. Rouse, A. Saleh, L. Scharmann, S. Silwal, V. Segovia, A. Sparks, J. Stack, Z. Tang, S. Tolos, S. Travers, B. Van Allen, J. Worapong TARGET AUDIENCES: Farmers Policy makers Academicians: plant pathology, ecology, genetics/genomics

Impacts
1.a. Our published evaluations of the invasive ability of the Karnal bunt pathogen have already been incorporated in discussions between the US and international trading partners. More complete information about infection risks for Karnal bunt will be important in trade negotiations with countries that currently limit imports of wheat from regions where the pathogen is present. 1.b. Because Kansas farmers have seen that the damage to wheat from wheat streak mosaic can be devastating, they manage intensively to remove the summer weeds and volunteer wheat that can form a green bridge to support the pathogen until wheat is planted again in fall. Our more complete analysis of WSMV risks will support mixed use of agricultural lands, balancing summer use of herbicides and tillage for disease management along with maintenance of pheasants and other wildlife. 1.c. Incorporating disease resistance genes in crop plants is generally the best approach to disease management. But pathogen populations can adapt to resistance genes in many cases, so that the useful life of a particular resistance gene may be limited. We are developing model predictions for gene resistance deployment strategies to inform decision-making in breeding programs in Kansas and beyond to extend the useful life of resistance genes. 2.a. Plant disease in natural systems has received little attention. We are providing the first information about the effects of environmental variation on plant disease in tallgrass prairie, with implications for likely pathogen problems if these species are developed in biofuel systems. Our long-term studies of disease in dominant tallgrass prairie species will provide an important reference point for evaluating disease risk if these species are grown in more intensive cropping systems. 2.b. Plant gene expression is a fundamental measure of adaptation of plants to stressful environments. We have developed the first application of microarray technologies for the study of stress responses of ecologically important plant species in natural systems, including methodologies that are being adapted by a number of other researchers. We are using this tool to better understand how plant species that may be developed in biofuel systems respond to changing environments and the trade-offs involved in responses to a set of stressors such as plant disease and drought stress.

Publications

  • S. E. Travers, M. D. Smith, J. Bai, S. H. Hulbert, J. E. Leach, P. S. Schnable, A. K. Knapp, G. Milliken, P. Fay, A. Saleh, and K. A. Garrett. 2007. Ecological genomics: making the leap from model systems in the lab to native populations in the field. Frontiers in Ecology and the Environment 5:19-24.
  • W. W. Bockus, Z. Su, K. A. Garrett, B. S. Gill, J. P. Stack, R. L. Bowden, A. K. Fritz, K. L. Roozeboom, and T. J. Martin. 2007. Number of experiments needed to determine wheat disease phenotypes for four wheat diseases. Plant Disease 91:103-108.
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