John Stephen Hartung

Research Plant Pathologist

Publications

Phone: 301-504-6374

 

 

Research Interests:

• Exotic diseases of citrus, defined as diseases that affect citrus production both in the United states and other citrus growing regions of the world

  • Establishment and maintenance of theExotic Pathogens of Citrus Collection
  • A quarantine greenhouse containing citrus pathogens from world-wide locations that are studied and analyzed by cooperators from the USA and many world-wide citrus growing countries.
• Development of rapid and sensitive DNA and RNA -based diagnostic methods to assist in plant quarantine and phytosanitary applications, specifically:
  • Citrus Tristeza Virus
  • Citrus Variegated Chlorosis
  • Citrus Canker
  • Huanglongbing (citrus greening)
  • Citrus Yellow Mosaic Virus
  • Citrus Chlorotic Dwarf virus
  • Citrus Leprosis

  Current Research:

  • Genetic comparison of Citrus Greening
  • Parasitic Dodder and Spread of Greening
  • Analysis of Seed from Greening Affected Fruit
  • Greening pathogen Location within Citrus Trees

  Support Staff:

  • Julia Cabrera-WoscekLab Technician
  • Cristina Gouin-Paul Horticulturist
  
  

  Cooperation :

  • Cooperating Institutions (USA):
    • University of Florida : Ronald H. Brlansky, Fred G. Gmitter
    • University of California, Davis: Cristina Davis and William Cheung
    • USDA ARS Ft Detrick, MD: William Schneider, Avijit Roy
    • USDA ARS Ft. Pierce, FL: Robert Shatters, Dongping Yuan, Mark Hilf
    • USDA ARS Kearneysville, WV: Zhongrang Liu
    • USDA ARS, Riverside, CA: Richard Lee, Fatima Osman
    • USDA APHIS CPHST: Beltsville, MD
  
  
  • Cooperating Institutions (Foreign):
    • Southwest China University, Chongqing, China
    • Huazhong Agricultural University, Wuhan, Hubei, China
    • CIRAD, FLHOR, Reunion, France
    • Fundecitrus, Araraquara, Sao Paulo, Brazil

  Current Grants and Outside Funding

  • Citrus Research and Development Foundation , Lake Alfred, Florida
    • Visualization and detection of proteins produced by 'Ca. Liberibacter asiaticus' in infected sweet orange plants and vector psyllids
    • HLB resistance through transgenic expression of short chain fragment variable antibodies against key Liberibacter epitopes
  • USDA NIFA SCRI
    • Rear and Release of Psyllids as Biological Control Agents: A Mid-term Solution for Huanglongbing (HLB) Disease of Citrus
  • Citrus Research Board , Visalia, CA
    • Development of cryotherapy as an approved method of eliminating graft transmissible pathogens in citrus biological indexing

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