ISSR Analysis And Preliminary SSR Analysis Of Genetic Variation In Medicinal Plant, Gastrodia Elata (Orchidaceae) And Its Conservation Strategy

Gastrodia elata B1.(Orchidaceae) is a rare and endangered medicinal plant. In this study, ISSR markers and SSR markers were used to examine the population genetic parameters of 8 natural populations and 6 cultivated populations of G. elata, with a total number of 483 samples. The 7 primers amplified a total of 77 unambiguous and reproducible bands, among which 64 bands were polymorphic and the percentage of polymorphic loci was 83.12%. The results showed genetic variation in natural populations were significantly higher than that of cultivated populations (P=59.09% vs. P=35.71%, A_e=l293 vs. A_e=1.164, H=0.176 vs. H= 0.100 and Shannon's I=0.270 vs. 7= 0.155), suggesting the cultivated populations are narrowly genetic-based and tend to be more genetic uniformity. UPGMA cluster analysis showed that natural populations and cultivated populations were distinctly separated into two groups. 5 pairs of SSR primers showed serious lack of heterozygote in both natural (H₀=0.06 vs. H_e=0.53) and cultivated populations (H₀=0.16 vs. H_e=0.47). Mean alleles and mean effective alleles in natural populations were both higher than those in cultivated populations (A=5.O5 vs. A=4.20,A_e =2.62 vs. A_e=2.59). And much more rare and private alleles were detected in natural populations (36) than those in cultivated populations(9). These also proved that natural and cultivated populations have differentiated from each other to some extent. Coefficient of gene differentiation (detected by ISSR) among 8 natural popultations was 0.2558 (G_st), which was well in accordance with results of AMOVA analysis (27.25% of the total genetic variation resided among populations). And coefficient of genetic differentiation detected by SSR was 0.198 (F_ST). These results indicated that natural populations were differentiated in a certain extent. Gene flow among natural populations was relatively...