ABSTRACT
Root volatile organic compounds (VOCs), their chemistry and ecological functions have garnered less attention than aboveground emitted plant VOCs. We report here on the identification of VOCs emitted by barley roots (Hordeum vulgare L.). Twenty nine VOCs were identified from isolated 21-d-old roots. The detection was dependent on the medium used for root cultivation. We identified 24 VOCs from 7-d-old roots when plants were cultivated on sterile Hoagland gelified medium, 33 when grown on sterile vermiculite, and 34 on non-sterile vermiculite. The major VOCs were fatty acid derived compounds, including hexanal, methyl hexanoate, (E)-hex-2-enal, 2-pentylfuran, pentan-1-ol, (Z)-2-(pentenyl)-furan, (Z)-pent-2-en-1-ol, hexan-1-ol, (Z)-hex-3-en-1-ol, (E)-hex-2-en-1-ol, oct-1-en-3-ol, 2-ethylhexan-1-ol (likely a contaminant), (E)-non-2-enal, octan-1-ol, (2E,6Z)-nona-2,6-dienal, methyl (E)-non-2-enoate, nonan-1-ol, (Z)-non-3-en-1-ol, (E)-non-2-en-1-ol, nona-3,6-dien-1-ol, and nona-2,6-dien-1-ol. In an olfactometer assay, wireworms (larvae of Agriotes sordidus Illiger, Coleoptera: Elateridae) were attracted to cues emanating from barley seedlings. We discuss the role of individual root volatiles or a blend of the root volatiles detected here and their interaction with CO2 for wireworm attraction.
Subject(s)
Coleoptera/physiology , Hordeum/chemistry , Volatile Organic Compounds/chemistry , Animals , Behavior, Animal/drug effects , Carbon Dioxide/chemistry , Carbon Dioxide/pharmacology , Coleoptera/growth & development , Gas Chromatography-Mass Spectrometry , Hordeum/metabolism , Larva/drug effects , Larva/physiology , Plant Roots/chemistry , Plant Roots/metabolism , Volatile Organic Compounds/pharmacologyABSTRACT
Wireworms (Coleoptera: Elateridae) are important soil dwelling pests worldwide causing yield losses in many crops. The progressive restrictions in the matter of efficient synthetic chemicals for health and environmental care brought out the need for alternative management techniques. This paper summarizes the main potential tools that have been studied up to now and that could be applied together in integrated pest management systems and suggests guidelines for future research.
