Investigations on the Infraspecific Variability of Hypericum perforatum L.

SUMMARY

The natural variability of Hypericum perforatum L. (Hyper-icaceae) serves as a sound basis for breeding programs. The aims of this work were to study its infraspecific diversity from a biological and chemical points of view, and to promote the breeding of varieties which would be suitable for growing under Hungarian climatic conditions.

At the beginning of our investigations, 18 accessions of different origin had been tested for two years (1996–1997), evaluating the overall population properties and the individual divergences. Outstanding individuals could be selected from the basic populations according to their promising production-biological particulars. Their lines have been studied through two subsequent vegetation cycles (1998–1999). During the investigation of morphological, phenological and production properties of taxa involved, degrees of seasonal and ontogenetical variability have been estimated within and among populations. Data of genetical stability and heritability of taxon characteristics have also been obtained.

Great individual divergences characterized the accumulation levels of hypericin derivatives, while flavonoid content was more stable within populations, influenced principally by genotype. The highest total content of hypericin derivatives (4.0–15.8 mg/g) have been found in the second year of cultivation, while that of the flavonoid content (23.6–30.1 mg/g) could have been measured in the third vegetation cycle. The taxa studied only in very few cases possessed excellent hypericin and flavonoid contents at the same time.

KEYWORDS:

• Hypericum perforatum L.
• hypericin
• flavonoids
• breeding