Resistance of wheat cultivars and lines to Schizaphis graminum (Hemiptera: Aphididae) under laboratory conditions

Greenbug, Schizaphis graminum (Rondani), is a worldwide pest of cereals including rice, sorghum, wheat, barley, etc. The relative impact of resistance modalities, including antibiosis and antixenosis, and tolerance of seven wheat cultivars and lines (three wheat cultivars, namely Kouhdasht, Bezostaya and Hirmand, and four wheat lines, namely ERWYT 87-7, ERWYT 87-8, ERWYT 87-15 and ERWYT 87-16) with different levels of resistance against S. graminum was studied under laboratory conditions in Ardabil, Iran. In the antibiosis test, S. graminum produced the most and fewest progeny on Kouhdasht and ERWYT 87-16 in the reproduction period, respectively. In the tolerance test, ERWYT 87-16 and ERWYT 87-7 had the highest tolerance against S. graminum. However, in the antixenosis test, we did not detect any significant differences among tested cultivars and lines in terms of the number of adult aphids attracted to them. Overall, the plant resistance index (PRI) values were greatest for ERWYT 87-16 (4.95) and ERWYT 87-7 (4.11) and least for Hirmand (1.11) and Kouhdasht (1.20).