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ARS Home » Southeast Area » Fort Pierce, Florida » U.S. Horticultural Research Laboratory » Subtropical Plant Pathology Research » Research » Research Project #431483

Research Project: Mitigating High Consequence Domestic, Exotic, and Emerging Diseases of Fruits, Vegetables, and Ornamentals

Location: Subtropical Plant Pathology Research

2017 Annual Report


Objectives
1. Develop a risk-based index to analyze potential emerging pathogens/pests to identify those with greatest negative impact on agriculture to guide future research. 2. Characterize ecology, biology, epidemiology, genetics, and vector and host (crop and weed) interactions of exotic, newly emerging, re-emerging, and domestic pathogens. 2a. Characterize the basic biology, molecular biology and genetics of ‘Candidatus Liberibacter asiaticus (Las),’ the bacterium associated with citrus huanglongbing (HLB), and molecular mechanisms of host resistance/tolerance to Las infection. 2b. Characterize the basic biology, molecular biology, vector interactions and/or epidemiology of Tomato chlorotic spot virus (TCSV) and other tospoviruses, Squash vein yellowing virus (SqVYV), ilarviruses and other viruses of vegetables, ornamentals, and weeds, and Xanthomonas fragariae [causing angular leaf spot (ALS) on strawberry]. 2c. Characterize meteorological components affecting the epidemiology of Asiatic citrus canker (ACC), and the interactions of the Asian leaf miner with ACC, citrus black spot (CBS), the Asian citrus psyllid with HLB, the interaction of thrips with TSV. 3. Develop/refine and deliver rapid, sensitive reliable detection/sampling methods for high consequence/economic limiting pathogens, including but not limited to citrus canker, huanglongbing, black spot, plum pox virus, seedborne pathogens, and insect vectored viruses of vegetables and ornamentals. 3a. Develop improved detection methods for tospoviruses, Las and Xanthomonads on citrus and strawberry. 3b. Develop new and augment existing surveillance methods and protocols for HLB and the other newly introduced diseases such as CBS and PPV. 4. Develop or improve comprehensive integrated disease management strategies to rapidly find and delimit new disease introductions and develop quarantine and control/mitigation/eradication programs for exotic pathogens. 4a. Develop and use stochastic models to test various disease control strategies for citrus and prunus diseases caused by exotic pathogens. 4b.Develop and implement the most efficacious strategies for disease management of HLB, Xanthomonads of citrus and strawberry, CBS, PPV, and viruses of vegetables and ornamentals.


Approach
The overall approach is to thoroughly characterize plant pathogens causing domestic, exotic and emerging diseases at multiple levels: assessment and prioritization of economic, production and political risk; cellular, molecular and/or biochemical levels of host-pathogen-vector interaction; and traditional and newer stochastic epidemiological analysis at regional and plantation levels. New pathogens will be identified and characterized by biological and traditional cultural methods. Recombinant DNA and genomics technologies will be applied to study host-pathogen interactions. Resulting knowledge will be used to develop new detection and sampling methods, and management strategies, for these pathogens.


Progress Report
Work on all objectives commenced with new project plan in late March 2017 and we are making progress expected to put us on track for fully meeting all of our milestones after the first complete year of the project. We are in the process of identifying crops and pathogens for the risk index. Liberibacter asiaticus basic and molecular biology, and genetic characterization, has continued from the previous project. Citrus, vegetable and strawberry pathogen surveys, and meteorological data compilation have been initiated. Virus and bacteria detection assay development initiated and canine detection trials have continued. Collection of spatial distribution data and development of epidemic models has continued.


Accomplishments