ELECTRON SHADOW MICROGRAPHY OF THE TOBACCO MOSAIC VIRUS PROTEIN

Two improvements are described in the use of shadow electron micrography for the observation of particles of macromolecular dimensions. One involves the substitution of gold for chromium as shadowing metal. The thinner gold film that can be employed gives a truer representation of the shape of particles so small that shape and size are significantly altered by the thickness of the shadowing metal deposited on them. The other consists in metal-shadowing small particles deposited on a very smooth surface such as that of polished glass and the handling of this metal film as a replica of the glass surface and the particles resting on it. This technique permits the photography of particles whose direct observation is disturbed by the fine structure that is brought out by shadowing a collodion substrate. Application of these methods to the electron micrography of the tobacco mosaic virus protein shows that its fibrils are rods about 125A both in height and breadth. Though the rods appear segmented, these segments have not been found to have a length that is constant or a small integral multiple of an underlying unit.     

侵染姜的烟草花叶病毒的鉴定

从莱芜市莱城区大田表现严重花叶的姜上分离到一种病毒,接种到１３ 科４３ 种鉴别寄主上,能侵染５ 科２５ 种植物。该病毒分离物的钝化温度为９５ ～９８ ℃,稀释限点为１０ － ７ ～１０ － ８ ,体外存活期为１２８ｄ 以上。提纯病毒呈典型的核蛋白吸收,最大吸收峰为２５８ｎｍ ,最小吸收峰在２４３ｎｍ , Ａ２６０／ Ａ２８０ ＝ １ ．３２ 。病毒外壳蛋白分子量为１７ ．３ Ｋ Ｄ,杆状粒体长度为３００ｎｍ ,该分离物与烟草花叶病毒的抗血清有明显的阳性反应。根据这些特性,该病毒分离物属于烟草花叶病毒属的烟草花叶病毒。     

烟草花叶病毒株系鉴定研究进展

烟草花叶病毒具有许多株系，因内外近十几年来主要在生物学，血清学上的生物化学和分子生物学等方面进行株系的研究。文章就上述研究进展作一简要综核实工针对某些研究方面阐述了一些见解和评论。