Intra-specific genetic diversity of Glycyrrhiza uralensis, a medicinal plant in the Altai-Dzungarian region, Mongolia
Plants and plant derivatives have been used as a main source of medicine in Mongolia to treat a range of diseases afflicting humans and their animals. Most medicinal plants are harvested from the wild and extensive usage has led to a danger of extinction for some species. Ex-situ conservation is an important part of plant diversity conservation and it could also help in filling the market demand. To prevent genetic diversity losses during the domestication process, it is important to select quality germplasm material. In this study we studied genetic diversity in four populations of Chinese liquorice (Glycyrrhiza uralensis Fisch.) in the Altai-Dzungarian region, Western Mongolia to determine (1) how genetically diverse are populations of G. uralensis in the study area and (2) if it is possible to select germplasm from any populations in the area for further cultivation. Leaf tissues of 15 individuals were sampled in each population for genetic analysis using the DNeasy Plant Mini Kit (Qiagen) and the dominant AFLP marker technique. Standard genetic diversity and differentiation measures were applied to assess genetic differences within and among populations provided by GenAlEx 6.5.
The percent polymorphic loci (Pp), the expected heterozygosity (He) within populations and Shannon’s index ranged from 53.1% to 64.1% (mean 57.4%), 0.148 to 0.198 and 0.232 to 0.301, respectively. The total mean heterozygosity was 0.171, which is relatively high for a vegetatively propagating legume. The comparison of the populations by Nei’s genetic distance shows that the population (kh) at the highest altitude (1556-1599 m a.s.l.) was genetically more distant from the other populations (0.042 to 0.071), while the latter three (1150-1330 m a.s.l.) have smaller genetic distances (0.027 to 0.39). The level of genetic diversity in the studied populations was higher than the average values for long-lived perennial herbs (Pp=41.3%, He=0.116). The results imply that it is possible to select germplasm from any population in the area for further cultivation.