Secoiridoids glycosides and root development in Gentiana lutea L. subsp. aurantiaca M. Lainz from the Northwest of the Iberian Peninsula

Abstract

Gentiana lutea L. subsp. aurantiaca M. Lainz is an endangered plant endemic of the northwest of the Iberian Peninsula. This subspecies is characterized by the colour of its flowers, ranging from orange to almost red. Like G. lutea, its roots have been collected for its high content in bitter compounds in order to be used mainly in the elaboration of bitter spirits and in medicine. HPLC chromatography has been used to study the variability in the concentration of bitter compounds (secoiridoids glycosides) between the roots of thirty-two wild populations of G. lutea subsp. aurantiaca from two areas of the Cantabrian Mountains. These concentrations were related to the root development, population altitude and edaphic traits. All the populations were growing in soils of siliceous origin with very acidic pH (4.2), very different to the other subspecies of G. lutea. Statistical analysis grouped the populations in two different clusters related to their geographical origin. The populations from Laciana, Babia and Omaña (LBO), regions of traditional collection, grow in soils richer in silt at a significantly higher altitude than those from the rest of the Cantabrian Mountains, allowing a higher development of the roots and a high potential in secoiridoids glycosides. Therefore, the establishment of regular cultivation of gentian in locations with the same characteristics as LBO regions, it would allow higher secoiridoid glycosides yield. So, the best populations could be selected and cultivated as a sustainable industrial crop.