Rheum tanguticum is an important but endangered traditional Chinese medicine endemic
to China. The wild resources have been declining. Establishing the genetic diversity of the
species would assist in its conservation and breeding program. Inter-simple sequence
repeats (ISSR) markers were used to assess the genetic diversity and population genetic
structure in 13 wild populations of R. tanguticum from Qinghai Province. Thirteen selected
primers produced 329 discernible bands, with 326 (92.94%) being polymorphic, indicating
high genetic diversity at the species level. The Nei’s gene diversity (He) was estimated to be
0.1724 within populations (range 0.1026–0.2104), and 0.2689 at the species level. Analysis
of molecular variance (AMOVA) showed that the genetic variation was found mainly
within populations (71.02%), but variance among populations was only 28.98%. In addition,
Nei’s differentiation coefficients (Gst) was found to be high (0.3585), confirming the relatively
high level of genetic differentiation among populations. Mantel test revealed
a significant correlation between genetic and geographic distances (r ¼ 0.573, P ¼ 0.002),
and the unweighted pair-group method using arithmetic average (UPGMA) clustering and
Principal coordinates analysis (PCoA) demonstrated similar results. Meanwhile, the genetic
diversity of R. tanguticum positively correlated with altitude and annual mean precipitation,
but negatively correlated with latitude and annual mean temperature. This result
might be an explanation that the natural distribution of R. tanguticum is limited to alpine
cold areas. We propose conservation strategy and breeding program for this plant.
to China. The wild resources have been declining. Establishing the genetic diversity of the
species would assist in its conservation and breeding program. Inter-simple sequence
repeats (ISSR) markers were used to assess the genetic diversity and population genetic
structure in 13 wild populations of R. tanguticum from Qinghai Province. Thirteen selected
primers produced 329 discernible bands, with 326 (92.94%) being polymorphic, indicating
high genetic diversity at the species level. The Nei’s gene diversity (He) was estimated to be
0.1724 within populations (range 0.1026–0.2104), and 0.2689 at the species level. Analysis
of molecular variance (AMOVA) showed that the genetic variation was found mainly
within populations (71.02%), but variance among populations was only 28.98%. In addition,
Nei’s differentiation coefficients (Gst) was found to be high (0.3585), confirming the relatively
high level of genetic differentiation among populations. Mantel test revealed
a significant correlation between genetic and geographic distances (r ¼ 0.573, P ¼ 0.002),
and the unweighted pair-group method using arithmetic average (UPGMA) clustering and
Principal coordinates analysis (PCoA) demonstrated similar results. Meanwhile, the genetic
diversity of R. tanguticum positively correlated with altitude and annual mean precipitation,
but negatively correlated with latitude and annual mean temperature. This result
might be an explanation that the natural distribution of R. tanguticum is limited to alpine
cold areas. We propose conservation strategy and breeding program for this plant.
The research has been published on Biochemical Systematics and Ecology.
Yanping Hua,c, Li Wang a, Xiaolong Xie b, Jian Yang a, Yi Li a,*,1, Huaigang Zhang a,**,1