TITLE:
A View of Diel Variation of Maize Odorscape
AUTHORS:
Ene Leppik, Toomas Tammaru, Brigitte Frérot
KEYWORDS:
European Corn Borer; Oviposition; GC-MS; SPME; Maize Pest; VOCs; Field Odorscape
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.5 No.6,
March
24,
2014
ABSTRACT: Volatile organic
compounds (VOCs) released by host plants attract gravid European corn borer
(ECB) female moths for oviposition. Despite extensive studies, little is known
about VOCs emitted by maize under natural conditions or the odorscape of a
maize field, particularly at the time of ECB oviposition. Here, we
characterized VOCs released by undamaged maize plants and VOCs in the maize
field odorscape. VOCs were collected throughout the diel cycle with solid-phase
microextraction fibres. VOCs were identified by GC-MS and quantified with
calibration curves. Four replicates per time period were collected; i.e.,
dusk, night, dawn, and day. VOC patterns differed between the maize plants and
the maize field odorscape throughout the diel cycle. At night, the period of
ECB oviposition, the VOC pattern was characterized by an increase in
monoterpenes, a decrease in sesquiterpenes, and the presence of methyl
salicylate, α-copaene, and
Z-3-hexenyl acetate. An apparent discrepancy between maize plant and field
odorscape VOC compositions was observed. Key compounds were identified as
putative host-cues, including methyl salicylate, α-pinene, 3-carene, p-cymene, limonene, and dimethyl nonatriene.
This study showed that VOCs were released by maize in a diel pattern, and
host-characteristic cues were present for nocturnal ECB oviposition.