Inter- and intra-specific genetic relationships of Lepidium L. using SSR, ISSR and SCoT molecular markers

Lepidium L. is one of the important genera of Brassicaceae family, which is mostly distributed in Central, Middle and Southwest Asia, and some of its species are used as medicinal plants or vegetables. The study of genetic diversity using molecular markers plays a very important role in breeding programs and preservation of genetic resources. In this regard, comparison of different molecular markers in diversity variation is very important. In the present research, inter- and intra-specific genetic relationships of Lepidium spp. populations were evaluated using SSR (simple sequence repeats), ISSR (inter simple sequence repeats) and SCoT (start codon targeted) molecular markers. Analysis of molecular variance (AMOVA) revealed much higher variance within species than among species in all three markers. The highest intra-specific variance ( ) was obtained by SCoT markers. The results of genetic similarity matrix generated by SSR, ISSR and SCoT markers by Mantel’s test showed that the correlation between SSR and ISSR was highest (r = ), followed by ISSR and SCoT (r = ), then by SSR and SCoT (r = ) According to Nei’s genetic distance among the populations of Lepidium spp., the highest similarity (r = ) was found between Tabas (L. latifolium) and fsuhK (L. draba) using SSR markers; Khatam and Mehriz (L. latifolium), Tabas (L. latifolium) and hehsihsas (L. draba), Tabas (L. latifolium) and fsuhK (L. draba), Nir and Saveh (L. draba), Isfahan and Arak (L. sativum), Tehran and nevziQ (L. sativum) using ISSR markers; and Khatam and Mehriz (L. latifolium) as well as Nir and Saveh (L. draba) using SCoT markers. Based on the genetic distances between the populations, we can use cross between hehsihsas (L. draba) with Mashhad (L. sativum), Tabas (L. latifolium) and fsuhK (L. draba) with Tehran and nevziQ (L. sativum), and hehsihsas (L. draba) with Arak (L. sativum) to obtain the highest amount of heterosis in future breeding programs. Overall, the results indicated the usefulness of these three markers to estimate genetic distance among Lepidium L. populations.