Comparision and determination of volatile compounds from Hippophae rhamnoides in natural forests and plantations.

In order to investigate why Holcocerus hippophaecolus causes serious damage in plantations of Hippophae rhamnoides but not in natural forests, the headspace volatiles emitted by leaves and trunks of the healthy and verminous H. rhamnoides in plantations and natural forests were examined by adsorption-thermodesorption and GC-MS identification. A total of 22 compounds were found. The analysis revealed that plants in plantations released more pentanal, E-2-hexenyl benzoate, 5-methyl-5-hydroxyhexanoic acid lactone and 3-methyl-1-butanol, while those in natural forests released more trans-2-decen-ol, 2-nonen-1-ol, 2-methyl-butanal and heptanal. After damaged by H. hippophaecolus, Eucalyptol, Terpineol, 2-Camphor were released in both types of forests, but the relative contents of Terpineol and 2-Camphor were higher in natural forests than those in plantations, in addition, the releases of aldehydes and alcohols were also enhanced. The variation of volatile compounds may be relevant to the different levels of the H. hippophaecolus damage between plantations and natural forests of H. rhamnoides.