Plant Virus Epidemiology: The Concept of Host Genetic Vulnerability

Author(s):  
J.M. Thresh
Author(s):  
O. E. Bradfute

Electron microscopy is frequently used in preliminary diagnosis of plant virus diseases by surveying negatively stained preparations of crude extracts of leaf samples. A major limitation of this method is the time required to survey grids when the concentration of virus particles (VPs) is low. A rapid survey of grids for VPs is reported here; the method employs a low magnification, out-of-focus Search Mode similar to that used for low dose electron microscopy of radiation sensitive specimens. A higher magnification, in-focus Confirm Mode is used to photograph or confirm the detection of VPs. Setting up the Search Mode by obtaining an out-of-focus image of the specimen in diffraction (K. H. Downing and W. Chiu, private communications) and pre-aligning the image in Search Mode with the image in Confirm Mode facilitates rapid switching between Modes.


Crop Science ◽  
1977 ◽  
Vol 17 (4) ◽  
pp. 632-634 ◽  
Author(s):  
N. L. Taylor ◽  
P. B. Gibson ◽  
W. E. Knight

Sign in / Sign up

Export Citation Format

Share Document