Genetic diversity analysis of Caragana microphylla population in different altitude gradients

Caragana microphylla is the most dominant and constructive shrub species.We evaluated the level of genetic variation within and among populations sampled from two different altitude gradients using inter-simple sequence repeat polymorphism(ISSR) molecular markers.The results showed that eight ISSR primers generated 142 bands,of which 126(88.73%) were polymorphic.Based on Nei's Gst value calculated by POPGENE,the gene diversity(h) and Shannon's information index(I) was 0.292 9 and 0.441 7,respectively indicating considerable genetic variations at the species level.At the altitude gradients,the genetic diversity index in populations from low altitude region was higher than from high altitude region,shows that the gene exchange between populations was blocked by the increase of altitude.