Detection of genetic and phytochemical differences between and within populations of Plantago major L. (plantain)

Leaves of Plantago major L. (common plantain) have been used for centuries almost all over the world as a wound healing remedy, and for other medicinal purposes. Polyphenols have been proposed to be responsible for many of the medicinal properties attributed to P. major. In this study, plants from 19 subpopulations (offspring families), derived from a total of five populations of P. major collected from different parts of Sweden, were screened for genetic variation with molecular markers, and for contents of major polyphenolic compounds. In addition to plantamajoside, four novel poplyphenolic compounds were identified and quantified. RAPD analysis demonstrated considerable between-population variation and very sparse within-population and within-subpopulation variation, just as expected for inbreeding species. Differentiation among populations was associated with the geographical distances between the sampled populations. Differences between populations and subpopulations in polyphenol contents did not reflect the DNA-marker based pattern, suggesting that the expression of the studied polyphenols was affected by, e.g., epigenetic inheritance or a very early environmental influence on the newly germinated seedlings, before potting and randomization.

► DNA-marker based differentiation among populations was associated with the geographical distances between the sampled populations.
► We found four novel major polyphenols in P. major leaves.
► Differences between populations and subpopulations in polyphenol contents did not reflect the DNA-marker based pattern.