Abstract
A virus-like disease of chrysanthemums occurs in Shizuoka prefecture, Japan. Symptoms of the disease include foliar necrosis and necrotic streaks on the stems. A pathogen isolated from diseased plants was transmitted by Frankliniella occidentalis. The pathogen reacted with Tomato spoted wilt virus (TSWV) antiserum in western blots in which a protein the same size as the TSWV nucleocapsid protein (NP) was detected. The pathogen had a broad host range, systemically infecting 23 species from 7 families out of 39 species from 11 families tested. An electron microscopy study of the pathogen using ultrathin sections of systemically infected Nicotiana rustica leaves revealed clusters of spherical particles 87 nm in diameter within cisternae of the endoplasmic reticulum and filamentous inclusions in the cytoplasm of infected cells. The NP amino acid sequence of the pathogen shared 97.7% identity with that of TSWV. From these results, the pathogen was identified as TSWV. A wide range of susceptibility to TSWV was found in chrysanthemum cultivars, and susceptibility varied greatly depending on the virus isolate.
