Genetic diversity within and among populations of Neopicrorhiza scrophulariiflora (Scrophulariaceae) in China,an endangered medicinal plant

Neopicrorhiza scrophulariiflora Pennel (Hong) (Scrophulariaceae) is an endangered medicinal plant, endemic to the Eastern Himalayas and the Hengduan Mountains. Levels of genetic variation and genetic structure of seven populations of N. scrophulariiflora in China were studied using inter-simple sequence repeat (ISSR) markers. Thirteen primers amplified 82 total loci from 7 populations composed of 136 individuals. All 82 loci were polymorphic, showing a percentage of polymorphic bands (PPB) of 100%, indicating considerable genetic variation at the species level. In contrast, a low level of genetic diversity within populations was detected with a mean PPB of 30.56%. In addition, Nei’s genetic diversity analysis (0.4073) and Shannon’s diversity index (0.5917) revealed similar genetic structure. High levels of genetic differentiation (Gst = 0.6955) and restricted gene flow (Nm = 0.2198) among populations were also detected. Anthropologic impacts, together with clonal propagation, genetic drift and geographical isolation might be the reasons which had shaped the genetic structure of this species.