Repeat domain diversity of avrBs3-like genes in Ralstonia solanacearum strains and association with host preferences in the field.

Genes homologous to avrBs3 of Xanthomonas were detected in 309 strains of Ralstonia solanacearum biovars 3, 4, and 5 but not biovar 1 or 2. A statistically significant association between the originating plant species and internal repeats of the gene was found. Sequences of repeats and variation between nearly clonal strains revealed evidence of frequent recombination.