Abstract
The annual plant Anastatica hierochuntica is an Ombrohydrochloric species where the seeds released from the canopy seed bank throughout several years. The genetic variations at the intra-and interpopulation levels were studied in the runnel microhabitat in Libya, Egypt and Saudi Arabia. The genetic diversity was detected by RAPD analysis of the DNA material. The amount of genetic variation within Anastatica hierochuntica populations reached 67.910 % of the total variance. The Nei's gene diversity ranged from 0.336 to 0.361 and the Shannon's diversity index from 0.506 to 0.588 showing relatively high values. The highest value of the gene diversity was obtained in the Libya population. Lower values of the Nei's gene diversity were obtained in the Saudi Arabia then in the Egypt populations. Strong linear relationships were obtained between the Nei's gene diversity and the total amount of annual rainfall (R-2 = 0.88) and between the differences in the total annual rainfall and the values of the fixation index between population pairs (R-2 = 0.83). The role of the dispersal mode in shaping the genetic variations in the species was discussed as the canopy seed bank was suggested to have great significance in the context of species evolution and conservation of genetic diversity.