Morphological production biological and chemical diversity of St. John's Wort (Hypericum perforatum L.)

The theoretical purpose of the present work was to study infraspecific diversity of Hypericum perforatum L. From practical point of view, we have tried to find taxa of specific chemical composition and advantageous production properties to develop varieties suitable for growing under Hungarian ecological conditions. Eighteen basic populations were involved in our investigations (1996-1998), which meant 3 groups of origins. Lines, selected in 1997, were also tested for two years (1998-1999), when the heritability of phenomena was examined. Regarding morphological traits, the values increased with the age and were influenced by growing areas and growing years. Both the population homogeneity and the distances among populations augmented due to ageing and as a result of selection, respectively. Among selected lines, four kinds of flowering behaviour were observed and can be described as very early, early, medium, and late blooming types. Evaluating the rather diverse production biological characteristics, we found that the values also increased by the age and as a result of selection. Moreover, yields were affected by growing area and growing year. During the three year life cycle, three kinds of production and hypericin accumulation tendencies were determined. We established that harvest with flowering top is advantageous, especially at those taxa where high stem ratio could be measured in the herba. A hyperosid-rich chemovariety with very low rutin content could be clearly distinguished, involving two accessions of different origin. This chemotaxon of special flavon glycoside spectrum proved to be fairly stable among different circumstances, during drug manipulation and even through selection. The filter fraction of processed herba drug contained the highest level of active substances. Concerning diversity of properties, the plants could be classified into two groups (stable and variable). Regarding variability of taxa, they were categorized also into groups based on productivity, lifetime, and adaptability.