02393naa a2200181 a 450000100080000000500110000800800410001910000160006024501340007626000090021052017100021965300200192965300310194965300190198070000180199970000230201777301710204011257082016-11-10       2016    bl uuuu     u00u1 u    #d1 aHARO, M. M.  aLeaves or flowers, what do you prefer? Chemical composition of essential oils mediated by plant structure.h[electronic resource]  c2016  aEssential oil composition depend on organs in which they were produced (root, leaf, flower). This chemical polymorphism influences the interaction among volatiles and biological macromolecules, such as proteins and enzymes, resulting in distinct biochemical properties. Objective: The aim of this study was to analyze changes in chemical composition of Tagetes erecta L. essential oils extracted at different plant organs. Material and Methods: Leaves and flowers were collected, in three replicates, during the morning after the dew-point (60 days after germination). All plant material was dehydrated at 30??C. Essential oil was obtained using 50 g of air-dried plant material by hydrodistillation for 2 hours in a Clevenger type system. Samples were subjected to a GC and GC-MS analysis. Variance among different essential oil treatments was initially submitted to a selective process of the compounds that accounts for the maximum explained variance through Stepwise discriminant analysis. The data from the compounds selected were submitted to a canonical variate analysis (CVA). The significance of the pairwise separation among treatments groups were determined using the Mahalanobis distance. Results and Discussion: The essential oils extracted from leaves and flower presented respectively 22 and 29 compounds. Plant organ significantly affected the oil composition (P &lt 0.001). The monoterpenes myrcene, limonene, (E)-β-Ocimene and (Z)-3-hexenyl benzoate were the main responsible for the variation in oil composition. Conclusion: Our results suggest the influence of plant organ in essential oil chemical composition of T. erecta, which need to be considered depending on the objective.  aBioinsecticides  aIntegrated Pest Management  aSemiochemicals1 aREBELO, A. M.1 aSILVEIRA, L. C. P.  tIn: SIMP??SIO IBERO-AMERICANO DE PLANTAS MEDICINAIS, 8., SIMP??SIO IBERO-AMERICANO DE INVESTIGA????O EM C??NCER, 3., 2016, Univali. Resumos... Itaja??: Univali, 2016.