Analysis of genetic diversity and similarities between different Lycium varieties based on ISSR analysis and RAMP‑PCR markers

The plant species Lycium, commonly known as box‑thorn, is a genus of flowering plants of the Solanaceae family. It is commonly used in Traditional Chinese Medicine (TCM) for its fruits. As there are numerous different species Lycium, the present study, aimed to analyze the genetic diversity and similarities between some of these species. For this purpose, samples from 16 Lycium species were collected, and cluster dendrograms were created using random amplified microsatellite polymorphism (RAMP)‑PCR and inter‑simple sequence repeat (ISSR) markers. A total of 1,249 bands were produced, where each random amplified polymorphic DNA (RAPD) primer had 2‑9 valuable bands with an average of 6, of which 89.05% bands were polymorphic by RAMP‑PCR. Genetic distances were observed among different cultivars or species, which had a similarity coefficient (SC) index of 0.37‑0.98. Similar to RAMP‑PCR, ISSR analysis of the Lycium DNA samples yielded an SC index of 0.36‑0.98. ISSR markers produced 956 bands with average of 5.9 bands per ISSR primer, and 88.28% of the bands were polymorphic. The SC index between sample 2 and sample 16 was found to be 0.72 by both RAMP‑PCR and ISSR, which clustered together, which indicated that these two cultivars have good genetic association, in spite of their vast geographic distance. On the whole, the present study performed a genetic analysis of different Lycium species, which may prove to be useful for the conservation of the genetic diversity of different Lycium species/cultivars, as well as of other plant species.