Volatile induction of three cereals: influence of mechanical injury and insect herbivory on injured plants and neighbouring uninjured plants

Abstract

Herbivore damage and mechanical injury to leaves can stimulate the emission of volatile compounds. It is well known that emission of these volatile organic compounds (VOC) from plants can influence interactions with pests and their natural enemies. In our experiment, we studied the VOC responses of Triticum aestivum cv. ‘Bombona’, Avena sativa cv. ‘Deresz’ and Hordeum vulgare cv. ‘Rastik’ under mechanical injury and/or adult cereal leaf beetle herbivory, Oelema melanopus (Coleoptera: Chrysomelidae). In the first part of our experiment, we confirmed that increased amounts of several green leaf volatiles (GLVs) and terpene VOC were released by tested cereal plants after leaf injury. The quantities of multiple induced VOC varied significantly between our tested cereals. When undamaged wheat, barley and oat plants were positioned near to mechanically injured or insect‐damaged wheat plants, these neighbouring uninjured plants of all three test cereals also emitted significantly more VOC than control plants. The degree of VOC induction was significantly greater when an uninjured plant was closer to an injured wheat plant. This phenomenon may be useful for crop protection, as VOC manipulation may result in improved pest management and help reduce the use of harmful pesticides.