Volatiles from different barley cultivars affect aphid acceptance of neighbouring plants

Abstract

Effects of volatiles from one plant on the aphid acceptance of a neighbouring plant were studied in laboratory experiments with four barley cultivars. With a compressor‐supported system, air was led over one plant and then over a test plant. After treatment, settling of apterae of Rhopalosiphum padi (L.) on the responding test plants was compared with that on control plants treated with air from no other plant or air from a plant of the same cultivar. In an untreated state the four barley cultivars did not show differences with regard to aphid acceptance. However, after exposure to air from another plant significant changes in aphid acceptance were found in seven of the 16 possible cultivar combinations of inducing and responding plants. Significant changes in leaf temperature were recorded in 11 combinations, indicating that the aphid response is part of a broader effect of plant‐plant communication. Two of the four cultivars showed significant intracultivar communication. The congruence between changes ...