Grant Information

DEVELOPMENT AND IMPLEMENTATION OF NEW CONTROL STRATEGIES FOR CITRUS HUANGLONGBING (GREENING)

Sponsoring Institution Agricultural Research Service/USDA
Status COMPLETE
Funding Source USDA COOPERATIVE AGREEMENT
Reporting Frequency Annual
Project Director DUAN Y
Accession Number 418631
Project Number 6618-22000-034-34S
Dates 2010-02-01 - 2012-03-31
Recipient Organization UNIVERSITY OF FLORIDA

HOMESTEAD,FL 33031
Keywords (greening)
asiaticus
bacterium
candidatus
chemical
citrus
control
detection
huanglongbing
liberibacter
pcr
plants
Research Effort Applied (30%)
Basic (60%)
Developmental (10%)
Classification Parameters
Knowledge AreaSubject of InvestigationField of SciencePercent
212 - Pathogens and Nematodes Affecting Plants 920 - Orange 1060 - Biology (whole systems) 60%
212 - Pathogens and Nematodes Affecting Plants 910 - Grapefruit 1040 - Molecular biology 40%
Goals / Objectives
Application of new chemical therapies to eliminate Huanglongbing (HLB) bacterium from HLB-infected citrus plants.
Methods (unparsed)

Implementation of chemical control strategies by applying new commerical device to deliver effective chemicals into citrus plants. Evaluation of the control efficacy of the treated citrus plants using PCR-based detection.

Methods
Implementation of chemical control strategies by applying new commerical device to deliver effective chemicals into citrus plants. Evaluation of the control efficacy of the treated citrus plants using PCR-based detection.
Project Timeline Tracking

Outputs

This research relates to inhouse project objective: 1. Characterize ecology, biology, epidemiology, molecular genetics, and vector and host (crop and weed) interactions of domestic, exotic, newly emerging, and re- emerging pathogens, and 2. Develop/refine rapid, sensitive reliable detection/sampling methods for pathogens. We have developed methods for sensitive detection of huanglongbing (HLB) bacterium and effective cleaning of HLB-affected budwood and seeds. The new detection method is able to detect extremely low titers of Las bacterium both in citrus seeds and plants that would be missed by the APHIS standard quantitative polymerase chain reactions (qPCR) detection method. We also demonstrated that orange jasmine hedges may be a minor source of HLB inoculum for nearby citrus groves, question the importance of Murraya paniculata as a reservoir of HLB, and revealed resistance to HLB in M. paniculata. While developing a rapid screening method, we have shown a new composition of two antibiotics (streptomycin and penicillin) is effective in eliminating the Las bacterium both in the budwood and plant treatments and in both greenhouse conditions and field trials. In addition, great progress has been made on an alternative treatment method that effectively mitigates or eliminates the disease using simple thermal therapy with optimized parameters. These technologies are being further evaluated and modified in field trials.