RÉSUMÉ
Objective To analyze the genetic diversity of Psammosilene tunicoides,an endangered and endemic medicinal plant,in southwest China.Methods The genetic diversity of seven representational populations of P.tunicoides including 137 individuals had been investigated by amplified fragment length polymorphisms(AFLP)maker technique.Results The genetic diversity had been revealed as follow:the Nei's genetic diversity index(He),Shannon's information index(I),percentage of polymorphic loci(PPB)were 0.243 4?0.179 1,0.373 5?0.248 5,and 82.30%,respectively at the species level;and 0.091 8?0.161 0,0.140 2?0.236 2,and 30.48%,respectively at population level.The genetic differentiation index(Gst)was 0.624 6 and genetic differentiation coefficient by Shannon's diversity(Ist)was 0.624 6.The result of dendrogram of seven populations indicated that Lijiang and Gejiu of Yunnan populations shared the maximum genetic identity,though they distributed in a relatively great geographical distance;Kunming population of Yunnan had the greater genetic distance from other populations.Nine characteristic fingerprint bands that can distinguish the different populations had been acquired.Conclusion The genetic diversity of P.tunicoides is relatively higher at the species levels,while lower within population levels,and a significant degree of genetic differentiation occurrs among the populations.There is little relativity between the relationship of populations and geographical distance.The combination of characteristic fingerprint bands between intraspecies and populations provide important basis data for germplasm resources diagnostics and plant breeding by AFLP maker technique.