|WANG, X. F. - Chongqing University|
|ZHOU, C. Y. - Chongqing University|
|DENG, X. - South China Agricultural University|
|IREY, M. - Us Sugar Corporation|
Submitted to: International Research Conference on Huanglongbing
Publication Type: Abstract Only
Publication Acceptance Date: 1/8/2011
Publication Date: 5/10/2011
Citation: Wang, X., Zhou, C., Deng, X., Irey, M., Chen, J. 2011. Genetic diversity of ‘Candidatus Liberibacter asiaticus’ strains. In: International Research Conference on Huanglongbing. p.34.
Technical Abstract: Huanglongbing (HLB) is a highly destructive disease of citrus production worldwide. The disease is associated with ‘Candidatus Liberibacter asiaticus’. Information about strain diversity of ‘Ca. L. asiaticus’ has been limited and is needed for research in disease epidemiology and bacterial biology. In this study, sequence diversity of a hypothetical protein gene (CLas5650) among 220 strains (156 from China and 64 from U.S.) of ‘Ca. L. asiaticus was analyzed. Results showed significant inter- and intra-regional variation within bacterial populations. Based on characteristic electrophoretic profiles of PCR amplicons generated by a specific primer set, six DNA genotypes [A (1143bp), B (1071bp), C (797bp), D (906 and 797bp), E (1071 and 797bp), and F (1071, 906 and 797bp)] were found in the China population and two DNA genotypes [G (1143 and 797bp), and B (1071bp)] were found in the Florida population. The China population consisted predominately of strains with genotype B (73.7%); the Florida population consisted predominately of strains with genotype G (91.7%). In the China population, strains from Yunnan Province harbored five genotypes (B, C, D, E, and F). Prophage genotypes detected in other provinces are: A and B in Guangdong, B and E in Guangxi, B in Fujian, and B, C, and E in Guizhou. Sequence analysis indicated that tandem repeat and sequence insertion/deletion were the main source of prophage genotype variation.