Abstract
Aphid is a serious threat to wheat production in Pakistan. It causes direct and indirect damage by sucking the cell sap and transmitting fungal and viral diseases, respectively. Modalities of resistance (antixenosis, antibiosis, tolerance) along with seedling bulk test were deployed to elucidate resistance in nine varieties of wheat (Pak-81, Millat-08, Lassani-08, Fareed-06, Faisalabad- 08, Miraj-08, Aas-11, Sahar-06 and Blue Silver) against aphid, Schizaphis graminum R. under laboratory conditions. All experiments were laid out in completely randomized design and resistance/susceptibility of the varieties was categorized in the terms of differential damage rating of aphid to host plants. Seedling bulk test revealed seven varieties (Pak-81, Millat-08, Fareed-06, Miraj-08, Aas-11, Sahar-06 and Blue Silver) to be susceptible and two varieties (Faislabad-08 and Lasani-08) moderately resistant to aphid. In antixenosis test, Miraj-08 and Fareed-06 were the least and Millat-08 was highly preferred. On Aas-11, Miraj-08, Lassani-08, Pak-81, Fareed-06 and Sahar-06, aphids were the least fecund and on Faislabad-08 were highly fecund in antibiosis mechanism of resistance. In tolerant test, Sahar-06 and Millat-08 proved to be highly tolerant while Fareed-06, Faislabad-08 and Aas-11 were least tolerant. Pak-81, Lassani-08, Miraj-08 and Blue Silver were moderately tolerant. Based on the current investigation, Lasani-08 is recommended as resistant varieties against wheat aphid.