First report of bacterial leaf and flower spot of Zinnia elegans caused by Xanthomonas campestris pv. zinniae in Hungary

摘要

In 2006, a serious outbreak of bacterial leaf and flower spot disease was observed on zinnia (Z. elegans cultivars Capricio and Mondo) grown in several parks in Budapest, Hungary. The disease initially appeared on leaves as diffuse, transluscent, circular spots surrounded by large chlorotic haloes. The lesions enlarged and became reddish brown in the centre and angular in shape. On the flowers at high humidity, small brown spots appeared, and the flower heads were disfigures and decayed completely. The sequence of the 16S-23s rDNA spacer region of the strain shared 99.7% identity with other X. campestris pv. zinnia strains available in the GenBank. This is the first report of the occurrence of this bacterium on zinnia in Hungary.