VIRUS DISEASES OF FOREST TREES

The tobacco necrosis virus was identified as the originator of the euonymus mosaic disease.
The virus was mechanically transmitted from spindle tree (Euonymus europaea L.) to cucumber cv.
Delikatess and to some other plant species.
It was purified from infected cucumber leaves by a differential and density gradient centrifugation and its main biochemical properties were determined as well.

Maple leaf perforation suspected to be of virus origin was studied on the maples Acer platanoides L. and A. pseudoplatanus L. The virus was mechanically transmitted by the homogenate prepared from naturally infected maple leaves and aphids (Drepanosiphum acerinum Walker). From the infected maple leaves and the aphids the virus was purified by differential high and low speed centrifugation followed by sucrose density gradient centrifugation.
The final preparation negatively stained and examined with an electron microscope contained spherical virus particles 30 nm in diameter.

Electron microscope examinations of ultrathin sections of naturally infected maple leaves and the aphids revealed the same particles.
Further experiments are necessary to identify this virus.

VIII International Symposium on Virus Diseases of Ornamental Plants

V. Subíková

https://doi.org/10.17660/ActaHortic.1994.377.43