Study On Population Genetic Of Sophora Tonkinensis Based On CpDNA And AFLP

Sophora tonkinensis Gapnep is a perennial shrub plant.It is mainly distributed in Guangxi.Alkaloid is the majior active constituents in S.tonkinensis.Many reports were focused on the identification and pharmacological effects of Sophora tonkinensis.However,the genetic diversity of S.tonkinensis has not been systematicly studied,which leads to have some obstacles in choosing the right conservation strategies.In this study,the genetic diversity of S.tonkinensis was systemically analyzed using AFLP and cpDNA—tag methods,which provide theoretical foundation for its phylogenetic relationship and auxiliary selective breeding.The main research results are as followings:1.The quality of DNA samples obtained by using three slightly different DNA extraction methods was compared from S.tonkinensis samples.The results showed that the genome of S.tonkinensis extracted by sample pretreatment method was the best.2.Five pairs of primers were screened for amplification of cpDNA markers from 48 S.tonkinensis populations.The variation sites contained 38 bases,with a 14.01%conversion rate and a 21.02%base translocation rate,indicating that 48 S.tonkinensis populations had a great variation.Haplotype diversity was 0.826±0.040 and 18 cpDNA haplotypes were recovered.Hap2,Hap3,Hap 1,Hap 14 and Hap 16 constituted network nodes.Other haplotype populations were diverged from nodes,and this result suggested that S.tonkinensis had undergone population expansion event in the history.3.AFLP analysis was used to estimate genetic variability within and among opulations of 69 S.tonkinensis populations collected from 23 locations.Five pairs of primers were selected for AFLP analysis.It was gained 1230 bands.Forty bands were selected for subsequent analysis to construct AFLP fingerprints,and five bands were selected for each pair of primers on average.Based on UPGMA clustering results,the investigated populations were divided into seven groups at 0.55 of similarity coefficient.Nei's diversity index was 0.4357,which indicated that S.tonkinensis had high level of genetic diverdity.In the meanwhile,populations from Daai village of Liuxu town,Jinchengjiang District of Hechi city,exhibited the highest genetic diversity level,while the S.tonkinensis from Jinchai town,Mashan County of Naning city exhibited the lowest genetic diversity level,and Nei' s diversity index were 0.3284 and 0.1182,respectively.Based on cpDNA and AFLP data,it was revealed abundant genetic diversity in S.tonkinensis,and S.tonkinensis had undergone population expansion event in history.Genetic differentiation among different populations were low,and genetic difference of the species existed mainly within populations.Sampling S.tonkinensis from different areas is very important to protect the genetice diversity of S.tonkinensis in future conservation work.