Effects of population, age, and cultivation methods on ginsenoside content of wild American ginseng (Panax quinquefolium).

Genotype and environmental effects on ginsenoside content among eight wild populations of American ginseng (Panax quinquefolium) were investigated. Root concentrations of six ginsenosides were determined at the time of collection of plants from the wild (T0) and 2 years (T2) after transplanting roots from each of the eight populations to each of two different forest garden locations. Both location and population had significant effects on root and shoot growth. Overall, ginsenoside Rb1 was most abundant, followed by Rg1 and Re. Concentrations of Rg1 and Re were inversely related among and within populations. The relative ranking of populations differed depending upon the particular ginsenoside and sampling time. The relative importance of genotype and environment was not the same for all ginsenosides. Ginsenoside Re was influenced by population but not location, whereas Rb1, Rc, and Rb2 were influenced only by location (environment), while Rg1 and Rd were influenced by both. Ginsenoside levels were consistently lower, but growth was consistently higher at the more intensively managed garden location.