Isolation of rice tungro spherical virions from the exuvae of Nephotettix virescence.

摘要

A batch of 70-80 viruliferous nymphs was encaged on tungro-affected TN-1 plants. The infected plants harboured both Rice tungro spherical virus (RTSV) and Rice tungro bacilliform virus (RTBV). After a period of 2-3 weeks, 70 exuvae were carefully picked-up from the infected plants and collected in 2 ml of 0.1 M phosphate buffer, pH 7.0. This preparation was shaken on Vortex shaker for 5 minutes. After a low speed centrifugation (6000 rpm for 5 minutes) to pellet the exuvae, a drop of supernatant was placed on a grid and stained with 2% uranyl acetate and examined under electron microscope. The electron microscope observations of the grids revealed the association of only spherical virions (RTSV) with the exuvae which were also found in a low concentration. RTBV could not be detected in the preparations. This is thought to be the first report of isolation of RTSV from exuvae of viruliferous nymphs of the vector Nephotettix virescens.