Resistance to Russian Wheat Aphid (Homoptera: Aphididae) in Tunisian Wheats

Abstract

Accessions of Tunisian wheats, comprising 203 durum wheats, Triticum Turgidum L. var. durum (2n = 4x = 28), and 10bread wheats, Triticum aestivum L. (2n = 6x = 42), were evaluated in a greenhouse for resistance to the Russian wheat aphid, Diuraphis noxia (Mordvilko). Quantitative damage ratings based on the amount of leaf rolling and chlorosis showed that 18 of the accessions had the highest levels of resistance to the aphid. Additional tests of seven resistant accessions showed that antixenosis, antibiosis, and tolerance were involved in various combinations.