EVALUATION OF WHEAT (TRITICUM SPP.) RESISTANCE TO THE RUSSIAN WHEAT APHID (DIURAPHIS NOXIA MORDVILKO)

The Russian wheat aphid (RWA), Diuraphis noxia (Mordvilko), is a serious pest of wheat. To identify RWA-resistant wheats, a total of 70 wheat genotypes, comprised of 47 commercial bread wheats (Triticum aestivum), 11 non-bread wheats (T. monococcum , T. durum and T. turgidum), and 12 endemic bread wheats were evaluated in greenhouse tests. Two successive mass screening tests resulted in the selection of 11 wheat genotypes resistant to RWA. These genotypes were selected based on the amount of leaf chlorosis and /or other types of leaf damage. Four more susceptible genotypes were selected to introduce a susceptible check, for future RWA-resistance studies. The correlations within and between different damage rating scales and plant height measurements were also determined.