ARS | Publication request: Population Genetic Analysis of “Candidatus Liberibacter asiaticus” From Multiple Continents

Submitted to: International Research Conference on Huanglongbing
Publication Type: Abstract Only
Publication Acceptance Date: November 5, 2010
Publication Date: January 10, 2011
Citation: Glynn, J.M., Bai, Y., Chen, C., Duan, Y., Civerolo, E.L., Lin, H. 2011. Population Genetic Analysis of “Candidatus Liberibacter asiaticus” From Multiple Continents [abtract]. International Research Conference on Huanglongbing. 1:5.

Technical Abstract: Huanglongbing (HLB) is currently the most destructive citrus disease in the world and has caused enormous economic losses in the citrus industry. In the United States (US), HLB is typically associated with the presence of a fastidious phloem-limited bacterium named Candidatus Liberibacter asiaticus (Las), though other Liberibacter species have also been associated with HLB. Unfortunately, very little is known regarding the population characteristics of Las and epidemiology of HLB. The recent release of the Las genome sequence has allowed for the development of molecular markers to better understand the origins, transmission, and population dynamics of the HLB-associated bacterium. From a starting pool of more than 100 putative simple sequence repeats (SSRs), a panel of 7 polymorphic molecular markers for Las was developed. Using this panel of markers, complete genotypic profiles for nearly 300 Las isolates from the US, China, India, Brazil, Cambodia, Vietnam, Taiwan, Thailand, and Japan were obtained. Analysis of these profiles identified two distinct clonal complexes of Las associated with HLB and indicates at least two separate introduction events associated with the occurrence of HLB in Florida citrus. The panel of markers should be useful for future population studies of HLB and may also aid in identification of segments of the Las chromosome associated with bacterial virulence.