Genetic variation and population genetic structure of Zanthoxylum armatum in China

Although Zanthoxylum armatum DC is an important economic plant with medicinal and edible value in China, the genetic diversity and population structure of Z. armatum are still unclear. In this study, 132 individuals of Z. armatum from eight populations in China were analyzed by ISSR molecular markers. The results showed that 128 clear DNA bands were amplified from 12 primers, of which 73.44% were polymorphic. The percentage of polymorphisms in the eight Z. armatum populations was 6.25–44.53%, Nei's gene diversity (H) was 0.025–0.1663, and Shannon’s information index (I) was 0.0324–0.2443; The index of gene differentiation (GST) between populations was 0.4803 and gene flow (Nm) was 0.5411. The value of genetic variation within the population was 55% whereas the value of genetic variation among the population was 45%. Both cluster analysis and population genetic structure analysis revealed Z. armatum accessions could be divided into three groups, Mantel test results showed that there was no correlation between genetic relationships and the geographical distance in Z. armatum populations. These data suggested the genetic diversity was low at the species level but high among the populations, and the gene flow was limited in Z. armatum. This study might provide a theoretical basis for collecting and conserving Z. armatum resources and selecting new cultivars.