Effect of Genetic Diversity on the Distribution of Endemic Species of the Genus Silene (Caryophyllaceae) in Saint Katherine Protectorate, Sinai, Egypt

Saint Katherine Protectorate (SKP) hosts 24% of Egyptian Silene species including the endemic ones. This study investigated five Silene species representing 17% of all Egyptian Silene ; three of them are endemic to Egypt ( S. oreosinaica , S. leucophylla , and S. schimperiana ). S. schimperiana was widely distributed in different areas in SKP, whereas S. oreosinaica was very rare and was spotted as two or three populations restricted to one habitat. Moreover, S. oreosinaica has not been recorded before this study since 1983. Phylogenies based on pollen micromorphology as well as on molecular data were constructed in order to describe the evolutionary relationship among these species leading to their distribution. Although phylogeny based on the pollen grain characteristics was resulted in the separation of Silene species into two groups, the first one included S. odontopetala subsp. congesta Boiss and S. oreosinaica with sub-clade included S. schimperiana and the second group included S. linearis and S. leucophylla , there was no obvious relationship among these species in the light of their distribution. Neighbor-joining (NJ) and unweighted pair group method with arithmetic mean (UPGMA) phylogenies showed that Silene species were divided into three clades; the first one included S. oreosinaica and S. odontopetala , which were closely related; the second one included S. schimperiana and S. linearis ; and the last clade had S. leucophylla . According to NJ phylogeny and principal coordinate analysis (PCoA), S. schimperiana has recent, evolutionary characters that could make it distantly related to the other species, suggesting that its wide distribution could be attributed to the adaptation of its genetic constitute to different conditions.