The lavender production is of significant importance for the international visibility of the french Rhône-Alpes region. Uses of lavender essential oil (EO) are based on the growing of 3 species (L. angustifolia, L. latifolia, L. stoechas and an hybride L. x intermedia) with marked. The genus Lavandula is an ideal model for understanding the origin of the diversity of volatile organic compounds (VOCs), especially terpenes. Lavenders have the advantage of having a wide range of distribution areas with different bioclimatic regions, a limited number of species (39) with diverse morphological and ecological caracteristics. In order to characterize the diversity of the VOCs accumulated in the genus and consider their evolution, we have analyzed (GC-MS) the VOCS accumulated by 29 species (some for the first time). As often, in plants, the production of VOCs in the inflorescences of lavender is subject to spatial and temporal regulation. The differential emission of VOCs over time in L. angustifolia is a well known phenomenon for farmers who have observed a different quality of EO depending on the maturity of the inflorescences at harvest. To correlate these variations with stages of plant development, we have analysed the temporal variations of the main VOCs in leaves and inflorescences (several years and cultivars) at the chemical level (GC-FID) and the molecular level (qPCR). Upstream of this research on the genus Lavandula different bioinformatic tools have been developed. In particular, the module “MSeasy " which can automate GC-MS data retrieval. This is a prerequisite for using lavender in the future as a model study of VOCS in Lamiaceae
