Resistance of Nine Wheat Cultivars and Lines to Greenbug, Schizaphis graminum (Rondani) in Iran

Greenbug, Schizaphis graminum (Rondani), is the main pest of wheat that can considerably limit profitable crop production, either through direct feeding or via transmission of plant pathogenic viruses. One of the most effective approaches of pest control is the use of resistant cultivars and lines. Based on the initial screening test of 35 wheat cultivars and lines, we selected five cultivars (Pishtaz, Omid, Yavaras, Akbari, and Bahar) and four lines (R1-10, R2-9, R3-16, and R3-17) with different levels of resistance to S. graminum for antixenosis and antibiosis experiments. In the antixenosis test, the number of S. graminum attracted on R1-10 was the lowest after 24, 48, and 72 hours. In life table study, S. graminum reared on Yavaras and R1-10 had the lower survival rate, fecundity, and reproductive period compared with other host plans tested. Values of the intrinsic rate of natural increase (rm), finite rate of increase (λ), net Reproductive rate (R0), and Doubling Time (DT) indicated lowest population growth of S. graminum, when fed on Yavaras (0.26 d-1, 1.30 d-1, 17.66 offspring and 2.62 days, respectively). Based on the antixenosis and antibiosis analyses in this study, we concluded that R1-10 and Yavaras were more resistant to S. graminum. These findings could be useful for integrated pest management of S. graminum in wheat fields.