Genetic diversity and genetic structure of Salvadora persica L., rare plant species in Rabigh province, Saudi Arabia: implications for conservation

Salvadora persica L. is a medicinal plant distributed in desert and subtropical regions. In Rabigh, the few persisting populations of this plant are exposed to overcutting, overgrazing and, recently, human habitation. The conservation of S. persica requires an assessment of their genetic diversity and genetic differentiation. We applied 40 simple sequence repeat (SSR) primers, with which 22 polymorphic loci were identified. The PIC values were varied between 0.858 and 0.967. 240 plant accessions were sampled from four sites in Rabigh: Wadi EL Khaneg, Wadi Al Johfa, Wadi Al Hakak, and Wadi Khurieba. The percentage of polymorphic loci PPL% were ranged between 60% and 32% and a considerable inbreeding value (F = 0.942). Elevated genetic differentiation among the populations and a low gene migration suggest isolation among S. persica populations. Several recommendations for the protection of the existing populations, including seed preservation, restoration of highly endangered sites, and management of cutting and grazing activities.