Populations genetic study of the medicinal species Plantago afra L. (Plantaginaceae)

Abstract

Plantago afra (Plantaginaceae) is the most medicinally important species in genus Plantago and it is native to the western Mediterranean region, West Asia and North Africa, and cultivated extensively in Asia and Europe for seed husk known as black Psyllium. We have no data on the population genetic structure of this species in the world. Therefore a population genetic and morphological investigation was performed through light on genetic and morphological variability in this taxa. We used ISSR molecular markers for population genetic investigation. Genetic diversity analyses revealed a moderate genetic variability within Plantago afra, while PCoA showed some degree of genetic admixture among populations. AMOVA produced significant genetic difference among populations. The Mantel test showed a positive significant correlation between the genetic and geographic distance of the studied populations. STRUCTURE analysis showed that there are different genetic groups in the studied populations. Morphometric analysis showed that one population differed in seed color and mean stem diameter. The same population contained specific allele combinations and differed genetically from the rest of the studied populations. Therefore, we considered it as a new variety within Plantago afra.