Zygophyllaceae is a heterogeneous family composed of approximately 285 species belonging to 22 genera. Delimitation of taxa within the family has repeatedly changed over time. The objective of the present study aims to characterize and discriminate 17 taxa belonging to 13 species and 5 genera of Zygophyllaceae; collected from different geographical localities in Egypt and Saudi Arabia. The genera examined were Zygophyllum (represented by two species), Tribulus (two species), Fagonia (seven species), Peganum (one species) and Seetzenia (one species). Epidermal surface sculpture as revealed by Scanning Electron Microscope (SEM) and Start Codon Targeted (SCoT) assay were used in an attempt to discriminate between the examined taxa. SEM exposed some structure more clearly showing distinct aspects of some epidermal features. Start Codon Targeted assay were performed using ten primers and a total number of 146 bands were detected with 76.03% polymorphism. The relationship among the studied taxa based on combined analysis of variation in morphological characters and SCoT polymorphism were examined. The cluster analysis and distance tree were constructed using the unweighted pair group method with arithmetic mean (UPGMA) of NTSYS-pc V. 2.0.
Zygophyllaceae, Peganum, Fagonia, SEM, Epidermal surface sculpture, SCoT assay.