AFLP fingerprinting and essential oil profiling of cultivated and wild populations of Sardinian Salvia desoleana

Salvia desoleana Atzei et Picci is a herbaceous perennial plant endemic to Sardinia, Italy. Its leaves are a source of essential oil, used in the pharmaceutical and cosmetic industries. Due to the increasing interest in the essential oils production, cultivated accessions have supplanted many wild populations which had become small, fragmented and isolated with a serious risk of genetic erosion. With the aim of preserving the local genetic diversity, AFLP fingerprinting has been used to facilitate the comprehensive evaluation of both cultivated and wild S. desoleana populations. A set of 165 polymorphic AFLP fragments was generated, revealing a genetic diversity (He) ranging from 0.11 to 0.22 in wild and cultivated populations respectively. Two major clusters were revealed by STRUCTURE analysis, one including wild and the other capturing the cultivated accessions. The divergence between the cultivated and wild materials was also confirmed by the analysis of molecular variance (FST = 0.52). GC/MS analysis performed on the essential oil extracts identified 37 compounds, eight of which (1,8 cineole, terpinolene, ? and ? thujone, camphor, terpinyl acetate, germacrene D and linalyl acetate) were strongly represented. Three main fractions were identified in the essential oils: monoterpenes, sesquiterpenes and diterpenes. All terpenes levels were significantly correlated with the AFLP genetic clusters (P < 0.0001), suggesting close correspondence between genetic groups and chemical profiles. This work aims to describe the integrated investigation of genetic and chemical diversity of S. desolena germoplasm, in order to improve the species yield and to plan a future conservation strategy.