Occurrence of Xanthomonas campestris pv. raphani on Tomato Plants in the Russian Federation

Bacterial spot of tomato, caused by X. vesicatoria (Group B) and X. gardneri (Group D) (Jones et al., 2004) has become a very important disease of tomato in the Russian Federation. It was reported previously that this plant can be affected by Xanthomonas campestris pv. raphani as well (White, 1930). Leaf spots and wilt symptoms were observed in 2006 on tomato fields located in Krasnodar, Stavropol, and Alania-Osetia regions. Forty-tree original strains were cloned and characterized based on colony characteristics and biochemical properties (Jones et al., 2004). Reference strains included XV153 (group A), NCPPB 422(T) (Group B), XV 938 (Group C), XV GA2, XV444 (Group D), and several X. campestris (NCPPB 528(T), PHW 231, and NCPPB 1946(T)). The genes gyrB, operon Xcc0006-Xcc0007 (genome of X.. ATCC 33913; da Silva et al., 2002), and gene cytP450 were amplified and sequenced in the strains. Analysis of the nucleotide sequences revealed a unique group (seven strains) isolated from diseased tomato plants collected in Alania-Osetia (North Caucasus) with symptoms of leaf spots and "black rot-like" wilting. Those strains were grouped together with X. campestris pv. raphani NCPPB 1946(T) from radish. The strains were amylolytic, pectolytic, and most similar to X. vesicatoria in other biochemical properties. This is the first report of X. campestris pv. raphani on tomato in Russia. http://www.actahort.org/books/808/index.htm