From diseased leaves of Lisianthus plants [Eustoma grandiflorum (Raf.) Shinn.] with necrotic stunt symptoms Nagano and Shizuoka prefectures in Japan, we isolated two viruses with a diameter of ca. 30 nm and tentatively named them Nag-4 and Shiz-1, respectively. Both viruses reproduced necrotic spots on healthy lisianthus plants after mechanical inoculation. Based on virion morphology, double-stranded RNA analysis, molecular mass of the coat protein (CP) and serological tests, the viruses were closely related to species in the genus Tombusvirus. In a comparison of the amino acid sequence of the CP genes, Shiz-1 had high identity with that of Tomato bushy stunt virus-nipplefruit strain (TBSV-Nf), whereas Nag-4 shared less than 87% identity with sequences reported for tombusviruses, suggesting that the virus might be a new species in the genus Tombusvirus. This is the first report of tombusvirus disease on lisianthus in the world.
A new bacterial disease was observed on leaves of broccoli (Brassica oleracea L. var. italica Plen.) in a field in Gunma Prefecture, Japan in 2001. The causal agent was identified as Xanthomonas campestris pv. campestris (Pammel 1895) Dowson 1939. Healthy seedlings were inoculated with the isolated bacterium, symptoms of the disease were reproduced, and the bacterium was reisolated from the margin of lesions on the leaves. We propose the name black rot of broccoli for the disease.