Abstract
Agronomical and biochemical parameters of seven Hypericum perforatum (St. John's wort) accessions grown at three experimental sites in Switzerland were
followed over a two year period (1995-1996). Significant effects of environmental
(= site) and genetic factors (= accession) on flowering dates, plant length, and plant
dry matter production (= plant yield) were observed in both years; rankings of sites
and accessions with regard to plant yield were similar in both years despite the fact
that the first year crop contributed only a minor part to the overall yield of both
years together. Maximum dry matter production per year reached 159 dt/ha for the total
plant and 54 dt/ha for the flowering segment (i.e. the pharmaceutically relevant,
upper segment of the plants comprising the majority of flowers). HPLC analysis of
the constituents covered eight secondary metabolites (amentoflavone, biapigenin, hyperforin,
hypericin, hyperosid, pseudohypericin, quercetin, rutin). Generally, secondary metabolite
contents were significantly lower in the first year of cultivation ranging from 12%
(hyperosid) to 83% (hyperforin) of the contents measured in the 1996-crop. Significant
genetic effects on the production of all tested secondary metabolites (except biapigenin)
were observed in 1996 whereas environmental effects appeared to be less distinct (except
for amentoflavone and pseudohypericin). In conclusion, genetic factors strongly affected
plant yield as well as secondary metabolite content in H. perforatum cultivation; the availability of genetically superior plant material next to improved
agrotechnological methods therefore is supposed to become a key factor for successful
future field production.
Key words
Hypericum perforatum
- Clusiaceae - field cultivation - genetic effects - environmental effects
