Population genetics of Hyphaene thebaica Mart., in Rabigh province, Saudi Arabia: Implications for conservation

Hyphaene thebaica is a perennial plant distributed in desert and subtropical regions of the world. In Rabigh Province, western Saudi Arabia, the few persisting populations of this species are exposed to many threats, including overcutting and, recently, human habitation. These threats are predicted to be exacerbated with the advancement of aridification caused by climate change. The conservation and revival of the diminished populations of H. thebaica requires an assessment of their genetic diversity and genetic differentiation. To accomplish this objective, we applied 10 simple sequence repeat (SSR) primer pairs, with which all are polymorphic loci. These polymorphic loci were used to determine the population genetics of 60 plant accessions sampled from 5 populations of H. thebaica located in five sites in Rabigh Province: Wadi EL Khaneg, Wadi Al Johfa, Wadi Al Hakak and Wadi Khurieba and Wadi Kuliayah . Low to moderate levels of genetic diversity were found in all populations (the values of the PPL% ranged between 52.5% and 22.5%) along with a decreased value of HT (0.388) and a considerable inbreeding value (F= 0.4552), which verified an obvious shortage of heterozygotes. High genetic differentiation among the populations and a low level of gene flow suggest isolation among the H. thebaica populations, which caused a severe deficiency in gene migration. The data obtained herein will inspire several recommendations for conservation the existing populations, including seed preservation, and management of human activities. All of these actions are urgently needed to prevent imminent extinction.