Genetic diversity and relationships of populations of three Lepidium species using combined data analysis of molecular markers

The genus Lepidium L. is one of the three large genera of the Brassicaceae family, which are used as vegetables or medicinal plants. Knowing the relationships and genetic diversity of Lepidium L. species by molecular markers is an ideal approach to improve and conserve of their germplasm.

The genetic diversity and relationships among 22 populations belonging to three species of L. sativum, L. draba and L. latifolium using combined data of SSR, ISSR and SCoT markers based on analysis of molecular variance, indices of genetic diversity, cluster analysis, principal coordinates analysis and genetic structure were investigated.

Analysis of molecular variance showed that the genetic diversity within the groups is more than between the groups. The highest and lowest genetic diversity was related to L. sativum and L. latifolium, respectively. The highest Nei genetic similarity matrix was observed between L. draba and L. latifolium and the lowest similarity between L. sativum and L. latifolium. Neighbor-Joining cluster analysis divided the Lepidium populations into three groups and there was a weak separation between the species, which was confirmed by principal coordinate’s analysis and genetic structure, and it seems to be due to the gene flow among the populations of different Lepidium species and the existence of a common gene pool between them.

The results showed that the populations of the three studied Lepidium species have a high level of genetic diversity and gene flow, which can be used as valuable genetic resources in breeding programs.