Deoxyribonucleic acid relatedness of 24 xanthomonad strains representing 23Xanthomonas campestrispathovars andXanthomonas fragariae

摘要

TwentyXanthomonas campestrispathotype strains, three non‐pathotype strains, and one strain ofX. fragariaewere studied by S1 DNA:DNA hybridization tests. The results of these tests do not support the retention ofX. campestrisas a single species. DNA reassociation values among many of the strains were low. Three clusters of closely related strains were observed, but nine strains did not cluster.Xanthomonas campestrispv.secaliswas more closely related toX. fragariaethan to any otherX. campestrispathovar. Mapping the host family upon a three‐dimensional genomic distance matrix of the xanthomonads suggested that strains attacking the same plant family usually show some relationship, but only a distant one. Thus, pathogenicity toward members of the same host family is not a measure of the genomic relationships of xanthomon