Thirty-six strains of Xanthomonas campestris pv. campestris (Xcc) isolated
from cabbage, kale and broccoli were identified according to their
pathogenicity, phenotypic and genotypic characterization. Pathogenicity was
confirmed by the injection method with a hypodermic syringe into the
mesophilic tissue of cabbage leaves. All strains were Gramnegative, aerobic,
catalase-positive, oxidase-negative, grew at 35?C, produced levan, H2S and
indole, did not reduce nitrate, hydrolyzed Tween 80, starch, gelatin and
esculin and did not show tolerance to 0.1 and 0.02% TTC. The strains produced
acid from d-arabinose, arginine, dulcitol, galactose, d-glucose, maltose,
mannose, sorbitol, sucrose and xylose. The genetic characterization was based
on the sequence analyses of 16S rDNA and ERIC and BOX PCR. Strains of
different pathovars were also used to compare PCR resulting patterns. BOX-PCR
of the strains from kale and broccoli, obtained using (GTG)5 primer, yielded
patterns with a high similarity level to pathovar reference strain Xcc. The
strains from cabbage yielded BOX and ERIC product patterns, distinguishing
them from the other tested strains and reference strains. 16S rDNA of the
representative strains was closely related to Xcc strain ATCC 33913. ERIC PCR
and BOX using (GTG)5 primer generated different Xcc patterns and were
effective in distinguishing strains from different plant hosts.
Cloning and characterization of a gene required for the secretion of extracellular enzymes across the outer membrane by Xanthomonas campestris pv. campestris.
