Effect of water stress and aphid herbivory on flavonoids in broccoli (<em>Brassica oleracea</em> var. <em>italica</em> Plenck)


  • M. A. M. Khan
  • Christian Ulrichs
  • Inga Mewis


The aim of this study was to determine changes within flavonoid levels in broccoli plants (Brassica oleracea var. italica Plenck) induced by water stress conditions and aphid herbivory. Three water treatments, well-watered, drought, and water-logged, were applied to plants. Two aphid species, the specialist Brevicoryne brassicae (L.) and the generalist Myzus persicae (Sulzer), were used to evaluate combination effects under water stress. Drought and waterlogged stress decreased plants water content and reduced the growth of broccoli. Analysis of flavonoids revealed that the broccoli variety 'Calabrese' only contained kaempferol. The kaempferol content was similar in all experimental plants after one week cultivation under various water treatments. However, after two weeks of water stress, significantly higher kaempferol amounts were detected in drought and water-logged broccoli plants compared to well-watered plants. Herbivory of the aphids' B. brassicae and M. persicae did not change the level of kaempferol in broccoli, regardless of the water treatment