Hypericin from Hypericum triquetrifolium in wild and under cultivation: variation revealed by genetic distance
Hypericin content and genetic diversity were studied in 27 wild populations of Hypericum triquetnfolium in Jordan. The wild populations were explored from arid to semi-humid areas (176 to 582 mm), growing in varied altitude (341 to 1577 masl). Hypericin content significantly varied among wild populations (0.03 to 0.14%), and negatively correlated with rainfall indicating increased percentages of hypericin in arid environments. Five populations with high hypericin contents were introduced for cultivation in 2006 and 2007. They were behaved differently and categories into (1) no increase in hypericin content over the wild, (2) continuous increase and (3) decrease then increase above the wild hypericin content. Genetic diversity among the wild popUlations was high, which distinguished populations into 5 clusters according to their geographical origins. A cultivated two years old Ramtha population significantly contained the highest hypericin content (0.156%). Ramtha superiority alleviated genetically by its clustering pattern and its genetic distance from the other populations. Hypericum triquetrifolium wild populations are potentially important source for hypericin that encourage their improvement and cultivation.