ISSR Analysis On Population Genetic Diversity Of Yuanzhi

In the present study ISSR (inter-simple sequence repeat) molecular markers were employed to investigate the genetic diversity within and among wild populations of Polygala tenuifolia and P. sibirica and cultivated populations of P. tenuifolia. The analyses of 25 wild populations of the two polygalas showed:(1) Both the UPGMA cluster analysis and the PCoA analysis displayed a clear separation of the two species; (2) Many indicators for diversity such as PPB displayed that the genetic diversity of the two species was relatively high; (3) At large geographical scales the genetic distances between the two species'populations were significantly, positively correlated to the corresponding geographical distances, which was consistent with the isolation-by-distance model. According to the above results some implications for the conservation of the two polygalas were discussed:(1) Find populations of the two species in large size within nature reserves currently established and make in situ conservation; (2) Grow more herbs as the substitution for wild ones.The analyses of 5 wild and 5 cultivated populations of P. tenuifolia from the main production areas showed:(1) Both the UPGMA cluster analysis and the PCoA analysis displayed that the wild population and the cultivated population from the same geographical area would be clustered first, indicating that cultivated populations is derived directly from near wild ones; (2) At small geographical scales the genetic distances between populations of the species have no significantly positive relationships with the corresponding geographical distances; (3) The genetic diversity of cultivated populations was lower than that of wild ones, which was caused by the extensive cultivation and biological characters of the species. According to the above results it was suggested that seed breeding of the cultivated polygala should be developed, and the relationship between the "genuineness" of the herb and its genetics.