Assessment of genetic diversity of Xanthomonas campestris pv. campestris isolates from Israel by various DNA fingerprinting techniques

Abstract

Three molecular typing methods were used to investigate genetic diversity among Xanthomonas campestris pv. campestris isolates obtained in Israel and others previously obtained from different geographical locations (collection isolates). Using pulsed-field gel electrophoresis (PFGE), amplified fragment length polymorphism (AFLP) and repetitive sequence-based PCR (rep-PCR), 22 different isolates were divided into 11, 12 and 13 differentiated genotypes, respectively. All collection isolates yielded different genotypes and, among the isolates from Israel, several new genotypes were found. These findings not only support the observed heterogeneity within X. campestris pv. campestris, but also suggest that variability at the genomic level in this pathovar is higher than previously estimated. Moreover, while previous studies suggested that PCR patterns obtained with integron-specific primers are conserved in most X. campestris pathovars, PCR patterns of this element yielded four different types among the X. campestris pv. campestris isolates tested, thus supporting the relatively high diversity in this pathovar. Although differences in pathogenicity were observed among isolates, assays using cauliflower and radish did not indicate a correlation between pathogenicity and genotype. © 2006 The Authors.