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United States Department of Agriculture

Agricultural Research Service


Location: Subtropical Insects and Horticulture Research

2013 Annual Report

1a. Objectives (from AD-416):
The purpose of this agreement is to carry out cooperative research and to set forth understandings between the Agricultural Research Service (ARS) and University of Florida (UF) for joint projects and co-location of UF and/or ARS personnel at research sites and facilities in Florida. 1. It is understood and agreed that while all parties are interested in basic and applied research: a. The ARS is concerned with results having regional or national application. b. The University of Florida and its Agricultural Experiment Station and Extension Service programs conduct research and outreach that addresses economic viability and environmental sustainability impacting agriculture, natural resources, and consumers in Florida while providing information that encourages the application of research-based knowledge for end users in Florida and the region/nation. c. The University of Florida and its Institute of Food and Agricultural Sciences, as well as other UF Colleges and departments, are engaged in research on a wide array of areas such as: plant breeding and genetics, soil sciences, plant sciences, molecular biology, crop health and production, water quality, crop improvement, pest management, biological control of invasive weeds, medical and veterinary entomology, irrigation and water management, bioenergy and environmental management covering both basic and applied problems. 2. Joint research projects, will be in cooperation with ARS and FAES, UF Extension Service, UF College of Agriculture and related departments within IFAS, and other UF Colleges, departments and units as appropriate to the joint projects.

1b. Approach (from AD-416):
The University of Florida (UF) Faculty, in eighteen departments and thirteen research and education centers, will conduct collaborative research with ARS research scientists at the following Florida ARS locations: Fort Pierce: The U.S. Horticultural Research Laboratory conducts research to develop new control methods for insect pests of citrus, vegetables and ornamentals; conduct basic physiological, biochemical and pathological research on postharvest problems of horticultural crops; develop new citrus varieties that have enhanced tolerance to environmental stress, resistance to diseases and pests, improved fruit quality and yield; combat bacterial, fungal, nematode and viral diseases of subtropical crops; develop alternatives for methyl bromide fumigation; understand the impact of horticultural crop production on water quality and water conservation; improve flavor and overall quality of products from citrus and subtropical fruits and to develop new byproducts from citrus processing waste; maintain flavor, nutrition and microbial stability of products from citrus and subtropical fruits while extending their shelf life. Canal Point: The mission of the USDA, ARS Sugar cane Field Station is to develop high-yielding, disease and stress-tolerant sugarcane cultivars, and also new pathology, soil, crop and water management technologies that result in improved sugar cane production efficiency and soil conservation. Fort Lauderdale: The mission of the USDA, ARS Invasive Plant Research Lab (IPRL) is to address the complex and multi-faceted problems of exotic plant invasions in natural and agricultural ecosystems. Invasions by exotic plants pose one of the most serious threats to the health and integrity of natural and agricultural ecosystems. In order to restore the function and biological diversity of these systems, managing pest plant populations is of critical necessity. The IPRL conducts research into the impacts of exotic plants as well as the safety and effectiveness of biological control and other methods used to manage invasive plants. Miami: The mission of the Subtropical Horticulture Research Station is to support the agricultural industries in the southern areas of the United States by providing environmentally sound research on: (1) the breeding and genetics of tropical and subtropical fruit and ornamental crops; (2) the interdiction and control/eradication of exotic insect plant pests; (3) the investigation of best management practices for various ornamental crops with an emphasis on substrate/nutrient interactions. Gainsville: The Center for Medical, Agricultural & Veterinary Entomology (CMAVE) conducts research aimed at reducing or eliminating the harm caused by insects to crops, stored products, livestock and humans. Research is directed not only at the insects themselves but at the pathogens they may transmit and at identifying inherent protective mechanisms in plants. Each unit of CMAVE has specific goals, but there are several commonalities with emphasis on both control and prevention. CMAVE work emphasizes biological and integrated pest management techniques, and and understanding how things work at the molecular level.

3. Progress Report:
This project is related to Objective 1: Create new genetic combinations of citrus, Objective 2: Screen germplasm for important traits and select superior individuals, Sub objective 1 D: Create new scions and rootstocks with potential resistance to huanglongbing (HLB) and citrus bacterial canker (CBC) by genetic transformation. A transgenic test site has been prepared at the U.S. Horticultural Research Lab's Picos Farm in Ft. Pierce, to support Huanglongbing/Asian Citrus Psyllid/Citrus Bacterial Canker (HLB/ACP/CBC) resistance screening for the citrus research community. There are numerous experiments in place at this site where Huanglongbing (HLB), Asian citrus psyllid (ACP), and citrus canker are widespread. The first trees have been in place for more than three years. The University of Florida (UF) has provided approximately 600 transgenic citrus plants expressing genes expected to provide HLB/canker resistance, which have been planted in the test site. UF planted an additional group of trees including preinoculated trees of sweet orange on a complex tetraploid rootstock that appeared to confer huanglongbing (HLB) resistance in an earlier test. Dr. Kim Bowman has planted several hundred rootstock genotypes, and Ed Stover 50 sweet oranges (400 trees due to replication) transformed with the antimicrobial peptide D4E1. Texas Agricultural and Mechanical College (Texas A&M )Anti-ACP transgenics produced by Erik Mirkov and expressing the snow-drop Lectin (to suppress Asian Citrus Psyllid (ACP) have been planted along with 150 sweet orange transgenics from USDA expressing the garlic lectin. Eliezer Louzada of Texas A&M has permission to plant his transgenics on this site, which have altered Candidatus (Ca) metabolism to target canker, HLB and other diseases. More than 120 citranges, from a well-characterized mapping population, and other trifoliate hybrids (+ sweet orange standards) have been planted in a replicated trial in collaboration with Fred Gmitter of University of Florida (UF) and Mikeal Roose of University of California Riverside. Plants are being monitored for Candidatus Liberibacter asiaticus (CLas) development and huanglongbing (HLB) symptoms. Data from this trial should provide information on markers and perhaps genes associated with HLB resistance, for use in transgenic and conventional breeding. Dr. Roose has completed initial genotyping on a sample of the test material using a "genotyping by sequencing" approach. So far, the 1/16th poncirus hybrid nicknamed Gnarlyglo is growing extraordinarily well. It is being used aggressively as a parent in conventional breeding.

4. Accomplishments

Last Modified: 05/24/2017
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