Submitted to: International Plant Protection Congress
Publication Type: Abstract Only
Publication Acceptance Date: March 1, 2004
Publication Date: May 13, 2004
Citation: Burd, J.D., Porter, D.R., Huang, Y. 2004. The role of non-cultivated hosts in shaping and maintaining biotypc diversity of a cereal aphid (Schizaphis graminum) [abstract]. In: Proceedings of the 15th International Plant Protection Congress, May 11-16, 2004, Beijing, China. p. 319. Technical Abstract: The greenbug (Schizaphis graminum) is the most serious pest of wheat (Triticum aestivum) and sorghum (Sorghum bicolor) in the Great Plains of the United States. Host plant resistance has been a primary management tool but its effectiveness has been limited by the occurrence of biotypes. Greenbug biotypes are subpopulations of the species that are capable of damaging previously resistant cultivars. In 1947, Dahms reported the first evidence for greenbug biotypes attacking small grains, however, the first use of the term was by Wood in 1961. Since that time there have been ten greenbug biotypes differentiated by their ability to damage resistant plants. Over the years, explanations of how and why greenbug biotypes have appeared has stimulated considerable debate. Until recently, it was assumed that greenbug biotypes arose in response to widespread planting of resistant crop varieties. However, ecological and genetic studies indicate that greenbug biotypes likely diverged on grass hosts prior to the advent of modern agriculture and biotypic diversity is a result of sexual reproduction combined with reproductive isolation through the development of non-cultivated hosts races.