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ARS Home Northeast Area Beltsville, Maryland (BARC) Beltsville Agricultural Research Center Molecular Plant Pathology Laboratory People John Hartung





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- Con Baker
- Wei Wei
- Rosemarie Hammond
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- John Hartung
- Ing Ming Lee
- Lev Nemchinov
- Anna Smigocki
- Yan Zhao

**MPPL Home****Citrus Home****Canker****CVC****CTV****CYMV****Greening****Leprosis** **Greening Genes****Dodder****Greening & Seeds****Greening in plants****Citrus Facts****Collection** citrus pathogen logo Citrus Greening Research Distribution of 'Ca. Liberibacter asiaticus' in infected sweet orange trees Wenbin Li, Laurene Levy, and John S. Hartung cartoon tree image depicting location and concentration of HLB within various parts of a citrus tree An illustration of the distribution and population levels of the pathogen*'Ca. Liberibacter asiaticus'* in a sweet orange infected by a bud graft and grown in a greenhouse. The colors indicate relative population densities from 10,000 cells/gram of tissue (navy blue) to 10,000,000 cells/gram of tissue (yellow) to 1,000,000,000 cells/gram of tissue (red). Notice that the mid-veins of the leaves are an excellent place to sample for bacteria. Notice also that the tree is completely infected, but that the populations of bacteria found in the tree varies greatly from site to site in the tree, which complicates sampling of trees for diagnostic tests. Orange line *For more information about citrus pathogens please contact**Dr. John Hartung*** *For more information concerning growing citrus please contact**Cristina Paul*** ** *Juicy Links logo* *Florida Juice Commision**** *University of Florida**** *Sunkist kid's stuff**** *The Ultimate Citrus Page**** *California Citrus Research Board**** *Citrus from Down Under- Citrus Australia**** *Texas Citrus**** ** Goes to non-federal site*


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