The Identification and the Classification of Tulip Breaking Virus and Cucumber Mosaic Virus found Infecting Tulip and Lily Plants

摘要

It is possible that there is more than one or virus strain associated with the disease known as breaking on tulip. It was attempted to obtain further information on the identification of the viruses. Two types of viruses viz, tulip virus (TV) and cucumber mosaic virus (CMV) were isolated in our experiments from tulip plants, naturally showing symptoms of breaking. TV showed symptoms only on tulip and lily (Lilium formosanum) by mechanical inoculation of leaf sap from tulip, and no symptoms were observed on other test plants. Mottle symptoms appeared on the developed leaves of lily about two weeks after inoculation followed by distortion and malformation of the leaves. The thermal inactivation point was between 65° and 75℃ for 10 min. exposure, and aging occurred after about 6 day-storage at 25℃ for leaf sap of infected L. formosanum. In fectvity was lost at a dilution of 1:50,000. The particles of TV were about 750 mμ in length and were rod-shaped. The virus identified as CMV showed systemic symptoms on test plants such as Nicotiana tabacum, N. glutinosa, Cucumis sativus and Solanum melogena. The thermal inactivation point was 65°-75℃, resistance to aging was 3-4 days at room temperature and about 40 days at -5℃. The dilution end point was 1:10,000. No tobacco necrosis virus was found in naturally virus-infected tulip in this experiment. On the other hand, three kinds of viruses were isolated from naturally infected lily plants, viz, coarse mottle virus (CM), virulent coarse mottle virus (VCM) and tulip virus (TV). The host range of CM, VCM and TV were found to be limited to the Liliaceae including tulip and onion, and no symptoms were observed on test plants of CMV or other families. Three viruses produced coarse or fine mottling of several species of lily leaves, and when strong symptom expression occurs at the bud stage, the flowers were varioulsy deformed with curled and narrowed perianth segments. They produced color adding or color removing in petals of tulip. The thermal inactivation point of CM was found to be between 70°and 75℃; those of VCM, between 65° and 75℃; those of TV, between 60° and 65℃. CM, VCM and TV were active after dilution to 1:5,000 and all these viruses were active after 3 days at 24℃. The particles of CM, VCM and TV were all about 750 mμ in length. It is strongly suggested that TV, CM and VCM would be considered as a strain of tulip breaking virus.