Fine-scale genetic structure of Medicago ruthenica Trautv.

We established two quadrats (25 m×50 m) in a valley (YF1) and on a hillside (YF2) in Keshiketeng Banner, Inner Mongolia. We sampled all Medicago ruthenica Trautv. individuals in the quadrats by fine-scale methods and characterized their genetic variation using eight pairs of simple sequence repeat (SSR) primers. We found that M. ruthenica had a high level of genetic diversity. Based on spatial autocorrelation, the individuals showed non-random adjacent mating at an interval of 9 m. At the same interval, we found lower genetic similarity in the YF1 population than in the YF2 population. Thus, we inferred that the rich genetic diversity of M. ruthenica might be shaped by historical and geographic factors in this area, with topography impacting gene flow patterns between the two fine-scale populations.