GREENHOUSE EVALUATION OF RED WINTER WHEATS FOR RESISTANCE TO THE RUSSIAN WHEAT APHID (DIURAPHIS-NOXIA, MORDVILKO)

The Russian wheat aphid (Diuraphis noxia, Mordvilko) (RWA) is responsible for significant economic damage to cereal crops in arid and semi-arid environments. In this research 20 red winter wheats originating from Iran were evaluated for resistance to RWA. Leaf rolling, leaf folding, and leaf chlorosis were measured using 0 to 3 scales. An overall mean damage score was calculated as the average of the three measured damage symptoms. Plants from seven central Asian accessions (PI222666, PI222668, PI225226, PI225267, PI225271, PI243630, and PI243642) had mean damage scores significantly lower (p < 0.001) than 'Stephens' wheat (RWA susceptible) and not significantly different from 'Border' oat (RWA resistant). These results are consistent with previous studies which found a high frequency of resistant wheats collected from the central Asian region.