Categorization of Six Wheat Plant Introduction Lines for Resistance to the Russian Wheat Aphid (Homoptera: Aphididae)

Abstract

Laboratory experiments were conducted to determine categories of resistance of 6 wheat, Triticum aestivum L., plant introduction (PI) lines (PI 47545, PI 94355, PI 94365, PI 151918, PI 225245, and PI 225262) identified previoúsly as resistant to the Russian wheat aphid, Diuraphis noxia (Mordvilko). A susceptible wheat standard, 'Stephens', and a resistant oat, Avena sativa L., standard, 'Border', were used for comparisons. PI 225245 displayed the highest resistance level to D. noxia of the 6 plant introduction lines and exhibited antixenosis, antibiosis, and tolerance to D. noxia. This was the only plant introduction line that was preferred less than the susceptible wheat standard. All 6 plant introduction lines displayed low levels of antibiosis (reduced daily nymphal production) even though aphids had longer nymphipositional periods and lived longer than on Stephens wheat. The 6 plant introduction lines also showed low to moderate levels of tolerance based on the percent reduction of dry weight after infestation with D. noxia.