Genetic variation within the sand-fixation species Caragana microphylla (Leguminosae) in Horqin sandy land detected by inter-simple sequence repeats analysis

Caragana microphylla is the most dominant and constructive shrub species in the Horqin sandy land in the northeast of China. We evaluated it's the level of genetic variation within and among populations sampled from two different populations types in Horqin sandy land by using inter-simple sequence repeat polymorphism (ISSR) molecular markers. The results showed that eight ISSR primers generated 106 bands, of which 87 were polymorphic. At the species level, genetic diversity was relatively high (P = 82.08%, h = 0.2831, I = 0.4233). Genetic variation in natural populations (h = 0.2152, I = 0.3169) was more than that in plantation populations (h = 0.2021, I = 0.3040). Based on Nei's GST value, more genetic differentiation among plantation populations was detected (GST = 0.7787). Six populations of C. microphylla clustered into two clades. These results have important implications for restoring and managing the degraded ecosystem in arid and semi-arid areas.