Variability of six secondary metabolites in plant parts and developmental stages in natural populations of rare Gentiana pneumonanthe

Abstract

Variability in the contents of representative secondary metabolites in Gentiana pneumonanthe individuals was investigated in relation to population origin, plant parts and developmental stage. Chemical analyses (HPLC) of six secondary metabolites (swertiamarin (SWM), gentiopicrin (GP), sweroside (SWZ), mangiferin (MGF), isoorientin (ISOOR), and isovitexin (ISOV)) were performed for individuals from six populations located within a 3 × 3 km area at Maljen Mt., and separately for below- and above ground plant parts in three developmental stages. Different plant parts showed pronounced differences in the contents of the six secondary metabolites and a high level of variability during the plant ontogeny. The highest contents of three dominant compounds (SWM, GP, and MGF) were detected in different developmental stages. Both below- and above ground plant parts contained GP, MGF, SWZ, and SWM at some developmental stages, whereas ISOOR and ISOV were registered in above ground parts. The full-flowering stage was characterized by the highest contents of MGF, GP, and ISOOR in aboveground-, and GP in belowground parts. In the post-flowering stage, a high content of MF was detected in below ground parts. The results of this study contribute to a better understanding of interpopulation, ontogenetic and between-organ variability in rare and threatened G. pneumonanthe.