Background: The vernacular name 'Harmal' is used for two plant species in Saudi Arabia,
i.e. Peganum harmala L. and Rhazya stricta Decne. Both are important medicinal plants which offer
interesting pharmacological properties.
Objective: This study aimed to evaluate the genetic diversity among different populations of harmal
based on chemical variations of alkaloids and molecular polymorphism.
Methods: Total alkaloids were extracted from plants of three populations of each species and estimated
by using spectrophotometer and the chemical compounds were analyzed by Gas chromatography mass
spectrometry (GC-MS). Molecular polymorphism was estimated by using the Inter Simple Sequence
Repeat (ISSR) fingerprints.
Results: The results showed that the alkaloids content of R. stricta was higher than P. harmala populations.
The GC-MS analysis revealed the presence of (65-53) compounds in R. stricta and P. harmala, and
the percentage of polymorphism was found to be 93.2%. Sixteen ISSR primers produced 170 scorable
bands with an average of 9.6 bands per primer and 75%-100% polymorphism. The cluster analysis using
the unweighted pair-group method of the arithmetic average (UPGMA) method based on combined data
of GC-MS and ISSR markers divided the six harmal genotypes into two major groups.
Conclusion: The existence of variations in chemical and genetic markers is useful for the selection of
potential genotypes for medicinal use, and for breeding lines for medicinal substances production to
spare wild plants from uncontrolled harvesting for folk medicine.