The Chemical Analysis of Wild Thyme Variability for the Enhanced Production of Bioactive Compounds and Agro-Ecosystem Sustainability in the Mountains of Pistoia (Italy)

The Pistoia Mountains exhibit a great variety of flora, particularly rich in aromatic plants, such as juniper, mint, savory, helichrysum, and thyme. Thyme is especially notable for its essential oil, typically displaying high thymol and carvacrol content. While the chemotype of thyme determined by its specific terpene composition is genetically controlled, environmental factors, plant age, and seasonality can influence terpene production. This article investigates the morpho-chemical variability of wild thyme plants collected from two different regions of the Pistoia Mountains, identifying five distinct chemotypes. The gas chromatography–mass spectrometry (GC-MS) technique was used to characterize the chemical profiles and determine the seasonal variation in terpene production, identifying spring and summer as the balsamic period, the optimal time for essential oil collection. Furthermore, high-value thyme clones were preserved through in vitro micropropagation, ensuring chemotype stability. These findings contribute to a deeper understanding of wild thyme biodiversity and provide a foundation for practical applications, including the development of value-added products like herb-infused cheeses, plant and animal disease treatments, and integrated pest management strategies in agricultural systems.