Ecophysiological and phytochemical characterization of wild populations of Inula montana L. (Asteraceae) in Southeastern France

- Pedoclimatic and morpho-physiological data of three populations were compared.
- Inula montana grows on south-facing sites with low nutrient availability.
- The plant tolerates large altitudinal and soil draining capacity gradients.
- Trichome density, leaf surface and floral stem length decreased at high elevation.
- Low-altitude populations under drought stress increase the sesquiterpene lactone content.

Inula montana is a member of the family Asteraceae and is present in substantial numbers in Garrigue country (calcareous Mediterranean ecoregion). This species has traditionally been used for its anti-inflammatory properties as well as Arnica montana. In this study, three habitats within Luberon Park (southern France) were compared regarding their pedoclimatic parameters and the resulting morpho-physiological response of the plants. The data showed that I. montana grows in south-facing poor soils and tolerates large altitudinal and temperature gradients. The habitat conditions at high elevation appear to affect mostly the morphology of the plant (organ shortening). Although the leaf contents of total polyphenols and flavonoids subclass essentially followed a seasonal pattern, many sesquiterpene lactones were shown to accumulate first at the low-elevation growing sites that suffered drought stress (draining topsoil, higher temperatures and presence of a drought period during the summer). This work highlights the biological variability of I. montana related to the variation of its natural habitats which is promising for the future domestication of this plant. The manipulation of environmental factors during cultivation is of great interest due to its innovative perspective for modulating and exploiting the phytochemical production of I. montana.

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