Virus and mycoplasma diseases of cotton and their control
1984
Pranee Hamelink | Supat Attathom | Thira Sutabutra (Kasetsart Univ., Bangkok (Thailand). Faculty of Agriculture. Dept. of Plant Pathology)
Attempts to isolate the causal agent of cotton leaf roll disease from infected cotton leaves collected from Saraburi Province were done by using seven chemical and physical isolation methods. It revealed that virus particles were observed only in the preparation obtained from employing the purification procedure modified from that of Rowhani and Stace-Smith (1979) for potato leaf roll virus. After the partially purified virus preparation was centrifuged through 10-40 % linear sucrose density gradients at 38,000 rpm. for 240 min, a single, opaque band was observed at 35-40 mm. below the meniscus. This band contained flexuous rod particles about 600-700 nm. in length when observed under the electron microscope. The virus particles appeared to be singly scattered when they were stained with 2 % phosphotungstic acid but they appeared in clusters when 2 % uranyl acetate and 2 % ammonium molybdate were used. The purified virus preparation had 320-200 nm. absorption spectrum characteristic of that of nucleoprotein with a A260/A280 value of 1.159.
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