Volatiles of Conifer Seedlings Compositions and Resistance Markers

Sammanfattning: Pine weevils cause major damage to newly planted conifer seedlings in reforestation areas. However, recent findings indicate that small (“mini”) seedlings, planted at the age of 7-10 weeks, are gnawed less by pine weevils than the larger, conventionally planted seedlings. Thus, it has been proposed that planting young conifer seedlings in clear-cut areas may reduce the damage caused by pine weevils. In attempts to determine why mini seedlings appear to be less damaged by pine weevils than “conventional” seedlings, the volatiles released by Norway spruce and Scots pine mini seedlings were investigated, since such chemicals are of great importance in herbivore-plant communication, inter alia acting as repellents, attractants or antifeedants.Volatiles from the seedlings were collected, separated and identified by solid phase microextraction (SPME) followed by gas chromatography-mass spectrometry.The results show that there are high levels of chemodiversity among both spruce and pine seedlings. Between-tissue and age-related variations in their emissions were also found.Norway spruce clones infested by mites were also examined to assess genotype- and pest-specific stress reactions of Norway spruce. Finally, the effects of certain spruce defense compounds on the behavior of the large pine weevil Hylobius abietis were examined.