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The ''Tulip breaking virus'' is one of five plant viruses of the family ''Potyviridae'' that cause color-breaking of tulip flowers. These viruses infect only two genera of plants: ''Tulipa'' (tulips) and ''Lilium'' (lilies), (family Liliaceae). ''Tulip-breaking virus (TBV), Tulip top-breaking virus (TTBV), Tulip bandbreaking virus (TBBV), Rembrandt tulip-breaking virus (ReTBV)'' and ''Lily mottle virus (LMoV)'' have all been identified as potyviruses by serology and potyvirus-specific polymerase chain reaction (PCR). In addition, sequence analysis of amplified DNA fragments has classified them all as distinct viruses or strains; recently TTBV has been found to be strain-related to turnip mosaic virus.〔(Dekker, Elise L.; Derks, Antonius F. L. M.; Asjes, Cees J.; Lemmers, Miriam E. C.; Bol, John F.; Langeveld, Simon A., "Characterization of potyviruses from tulip and lily which cause flower-breaking", ''Journal of General Virology'': 74, 1993, p. 881-887. )〕 Tulip breaking virus is a member of the potato virus Y group; a distant serological relationship to tobacco etch virus was discovered in 1971.〔Bartels, Phytopathology Z., vol. 71, 1971, p. 87.〕 Also known as the ''Tulip break virus'', ''Lily streak virus'', ''Tulip mosaic virus'', ''Lily mosaic virus'', or simply ''TBV'', tulip breaking virus is most famous for its dramatic effects on the color of the tulip perianth, which helped to cause the speculative price of rare tulip bulbs during the period of so-called "Tulip mania" in the 17th century Netherlands.〔Garber, Peter M., "Tulipmania", ''Journal of Political Economy'', v. 97, 3, 1989, p. 535-560.〕 ==Effects of the virus== The virus infects the bulb and causes the cultivar to "break" its lock on a single color, resulting in intricate bars, stripes, streaks, featherings or flame-like effects of different colors on the petals. These symptoms vary depending on the plant variety and age at the time of infection. Different types of colour-breaks depend on the variety of tulip and the strain of the virus. The color variegation is caused either by local fading, or intensification and overaccumulation of pigments in the vacuoles of the upper epidermal layer due to the irregular distribution of anthocyanin; this fluctuation in pigmentation occurs after the normal flower color has developed. Because each outer surface is affected, both sides of the petal often display different patterns. In the lily species, the virus causes mild to moderate mottling or streaking in the leaves about two weeks after inoculation, and then causes the plant to produce distorted leaves and flowers.〔Brierly, P.; Smith, F. F., "Study on lily virus diseases: the mottle group", ''Phytopathology'': 34, 1944, p. 718.〕 The virus also weakens the bulb and retards the plant's propagation through offset growths; as it progresses through each generation the bulb grows stunted and weak. Eventually it has no strength to flower, and either breaks apart or withers away, ending the genetic line. For this reason the most famous examples of tulips from color broken bulbs – the ''Semper Augustus'' and the ''Viceroy'' – no longer exist. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Tulip breaking virus」の詳細全文を読む スポンサード リンク
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