PNNL

Abstract

Soybean cyst nematode (SCN, Heterodera glycines Ichinohe) represents one of the most serious threats to the stability of soybean crops in the United States. Variability in SCN populations was noted soon after the discovery of SCN in North Carolina in 1954. Resistant varieties and rotation to non host crops have been the most effective in reducing the SCN egg population density. Use of plant resistance has selected SCN populations which are able to reproduce on different sources of plant resistance. Although it is well accepted that these differences in virulence are not associated with any morphological differences in the various SCN populations, knowledge of biochemical differences is lacking. Therefore, the protein profiles of five different SCN populations were characterized using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) in order to identify similarities and differences in their most prominent proteins. Out of 25 major proteins ranging in molecular weight from 40 to 200 kDa, no major biochemical differences were observed between any of the populations. These results suggest that SCN populations are biochemically similar, and that any real differences in protein composition or relative expression are small compared to the resolution of SDS-PAGE.