NEW SOURCES OF RESISTANCE TO GREENBURG IN WHEAT

A new greenbug [Schizaphis graminum (Rondani)] Biotype G (GBG) damages all known sources of resistance in wheat (Triticum aestivum L.) and poses a potential new threat to wheat production. Resistance to GBG was detected in germplasm originating from hybridizations using x-ray irradiated pollen of wheat/rye (Secale cereale L.) hybrids to pollinate hard red winter wheat females. The GBG-resistant wheat germplasms exhibited high levels of resistance to all economically important greenbug biotypes (i.e, B,C,E, and G) at the seedling stage. This germplasm should be extremely valuable in the development of new multibiotype greenbug-resistant cultivars.