Seedling bulk test (mass screening) of fifty wheat genotypes against Schizaphis graminum (Rondani) (Aphididae: Hemiptera)

Abstract

Greenbug, Schizaphis graminum (Rondani), (Hemiptera: Aphididae), causes heavy losses to wheat crop by directly sucking the cell sap of the plant, and indirectly, by transmitting viral diseases such as barley yellow dwarf virus. Screening of fifty wheat genotypes against S. graminum was conducted in the Entomology laboratory of Agricultural Research Institute, Tarnab-Peshawar, Pakistan. These genotypes were ranked resistance/susceptible at resistance rating scale (0-6) on the basis of mean number of S. graminum per seedling where '0' shows Immunity (I); 1, highly resistant (HR); 2, moderately resistant (MR); 3, lowly resistant (LR); 4, lowly susceptible (LS); 5, moderately susceptible (MS); and 6, highly susceptible (HS). Twelve genotypes were found highly resistant, twelve were moderately resistant while ten were lowly resistant. Ten genotypes were ranked as lowly susceptible, two were moderately susceptible while four genotypes were highly susceptible. This study provided preliminary information on the resistance/susceptibility status of tested genotypes against this aphid.