Charles R. Krause
The United States Department of Agriculture (USDA), in cooperation with The Ohio State University/Ohio Agricultural Research and Development Center (OARDC), has unique opportunities for floricultural and nursery crop research at OARDC and for enhancing cooperative federal and state programs.
A cold field emission scanning electron microscope (CFESEM), a variable pressure scanning electron microscope (VPSEM), and a transmission electron microscope were recently purchased with joint federal and state funds.
The United States Department of Agriculture, Agricultural Research Service (ARS), Application Technology Research Unit (ATRU), and the Ohio State University's Ohio Agricultural Research and Development Center combined resources to upgrade the College of Food, Agricultural, and Environmental Sciences' electron microscope facility located on Ohio State University's campus at Wooster. The new name of this facility is the Molecular and Cellular Imaging Center (MCIC), which now includes additional equipment capable of performing molecular biological analyses.
A substantial savings of more than $250,000 was made possible with this joint acquisition through multi-instrument and federal purchase discounts in 1999. Such joint purchases permit the efficient use of federal and land-grant agricultural funds, stimulating increased cooperative research projects with graduate students, post-doctoral cooperators, and visiting scientists. At the same time, such joint purchases avoid the duplication of facilities.
This new imaging technology allows improved digital electron microscopy technology using CFESEM and VPSEM and provides higher magnification and clearer views of agricultural phenomena to solve some of the problems of American agriculture.
Higher resolution and visualization of newly developed biological pesticides, disease development, and pathogens and pests is now possible - at a level five to 10 times better than was previously possible. The Center also provides the opportunity for the performance of good science to answer difficult, long-term environmental questions involving food safety, water quality, and worker protection.
One of the long-term goals of both institutions is the reduction of pesticide usage through more efficient spraying and distribution. This goal will be enhanced by the following:
This new equipment permits clearer imaging of much smaller features with higher magnification of target surfaces than was previously attainable. Increased performance in numbers of observations and analyses with minimal specimen preparation time greatly improves analytical turn-around time.
Specific studies are:
A photomicrograph of the fungus that causes apple scab disease on crabapple (x1500) taken with the new cold field emission scanning electron microscope located at the OARDC.
|Comparison of Electron Microscopes|
|Å / 20kV;|
|Au, Pd, C, etc.||Yes||Plants, insects, animals.|
|50 Å / 25kV,|
SE: > x100,000
|Not required||Not presently|
|Hydrated plants, |
insects, in situ
|12Å @ 15kV|
SE: > x300,000
BSE: > x50,000
|Varies, usually not||Yes|| Plant surfaces|
insects, or animals.
Krause, C. R. and R. C. Derksen, R. D. Brazee and R. D. Fox. 2000. Cold field emission scanning electron microscopy permits unique views of plant pathogens. Phytopathology 90: S43 (Abstract).
Krause, C. R. and R. C. Derksen. 2000. Comparison of electrostatic and coldfog sprayers with cold field emission scanning electron microscopy and energy dispersive X-ray microanalysis. Proc. British Crop Protection Council. Brighton, UK. (In press).
A portion of this research was supported by grants from the Horticultural Research Institute.