Population genetic diversity and divergence of the halobiotic herb Limonium sinense estimated by AFLP and ISSR, and implications for conservation

Abstract

Limonium sinense is a halobiotic herb endemic to China that has been traditionally used for hundreds of years for its good restorative function. Genetic variation and population structure of this species were investigated by using amplified fragment length polymorphisms (AFLPs) and inter simple sequence repeats (ISSRs). A high level of genetic diversity was detected [AFLP: HE = 0.284, percentage of polymorphic loci (PPL) = 92.68 %; ISSR: HE = 0.257, PPL = 85.71 %] at the species level with POPGENE. Based on analysis of molecular variation (AMOVA), the among-population component accounted for 29.03 % (AFLP) and 28.81 % (ISSR) of the genetic variation, indicating that most of the genetic variation was between individuals within populations. The Shannon diversity index (I) was higher for AFLP (0.432) than for ISSR (0.395). Five main clusters were shown in the unweighted pair-group method with arithmetic mean (UPGMA) dendrogram created using TFPGA, consistent with the result of principal coordinate analysis using NTSYS. In situ conservation is advocated first. Keeping a stable environment for this halobiotic herb is necessary. For ex situ conservation, it is important to establish a germplasm bank. AFLP and ISSR markers were proved to be efficient tools in assessing the genetic variation among populations of L. sinense. The patterns of variation appeared to be consistent for these two marker systems, and they can be used for management of genetic structure, protection of the halobiotic plant, and conservation of germplasm.