Analysis on genetic diversity of different integrity population of Rhododendron delavayi by AFLP markers

The genetic diversity of fi ve different integrity populations of Rhododendron delavayi were investigated and analyzed by using the technology of amplifi ed fragment length polymorphism(AFLP). Seven pairs of AFLP primer combinations were selected and from these 527 AFLP fragments were obtained, of which 382 fragments were polymorphic, accounting for 72.49%. The percentage of polymorphic of 5 populations varied from 52.23% to 69.64%, and the average percentage of polymorphic fragments was 57.80%. Nei's gene diversity varied from 0.113 9 to 0.173 8, and Shannon information index varied from 0.186 8 to 0.277 7. In addition, the gene differentiation coeffi cient(Gst) was 0.186 8, which showed that 83.12% genetic diversities existed within the populations. Nm was 2.462 4, which indicated that the gene fl ow was enough to maintain the current genetic structure. Analysis of molecular variance(AMOVA) implied that the genetic variation among populations was 18.34%, while 81.66% of the genetic variation existed within populations. The five populations could be divided into three groups based on the results of UPGMA. Zixishan and Bandengshan populations, Maxiongshan, and Xiaoyingdi population each became a group, while Laowandi population was alone as a group. The fi ndings showed that although some populations were disturbed by human being but also held higher genetic diversity.