Greenbug (Homoptera: Aphididae) Resistance in Sorghum: Characterization of KS 97

摘要

The greenbug, Schizaphis graminum (Rondani), has been a major insect pest of sorghum, Sorghum bicolor (L.) Moench since 1968. Although sources of resistance have been identified to combat this pest, new and virulent biotypes have evolved to overcome most sources of genetic resistance in sorghum. KS 97 was developed and released in 1998 by the Kansas State University Agricultural Experiment Station as a new sorghum germplasm source of resistance to biotype I greenbug. The objectives of this study were to evaluate the seedling responses of KS 97 to greenbug biotype I infestation and to characterize the mechanisms of resistance that may be involved. KS 97 seedlings were evaluated for seedling responses to biotype I greenbug in experiments comparing all known resistant sorghum genotypes. The results of these studies indicated that KS 97 was as resistant as PI 550610 and PI 550607 to biotype I greenbug and was significantly more resistant than Cargill 607E. KS 97 was compared with a greenbug- susceptible sorghum hybrid to determine mechanisms of resistance that might be involved in expression of this trait. The results of these experiments indicated that KS 97 expressed significantly higher levels of antibiosis and tolerance than did the susceptible hybrid 550E. KS 97 should provide useful and potentially unique biotype I greenbug resistance genes in sorghum.