Use of morphological features and amarogentin content for characterization of wild yellow gentian (Gentiana lutea L.) populations in north-east Italy

During the summer of 2010, a survey aiming to assess the morphological characteristics and the amarogentin content of different wild populations of yellow gentian (Gentiana lutea L.) was carried out in the south-eastern Italian Pre-Alps (1050-1950m above sea level). The focus of the survey was the province of Trento where seven populations were recorded. Two more populations were recorded in the province of Brescia, which represented the southern and western limit of the targeted area, respectively. The last two populations were found in the province of Vicenza and Pordenone, the latter corresponding to the eastern boundary of the research area. A series of qualitative and quantitative parameters were recorded for each site/population and univariate (Kruskall-Wallis test) and multivariate (principal component analysis and cluster analysis) analyses were performed to estimate differences between populations. According to the descriptors recorded, a large variability emerged among all the targeted populations, nine of which belonged to the subsp. lutea and vardjanii Wraber complex, whereas the two populations from Vicenza and Pordenone provinces belonged to the subsp. symphyandra Hayek. These last are characterized by a later flowering, larger corolla lobes, and taller stems and roots, and are richer in amarogentin compared with the other populations.