BIODIVERSITY OF SOME PTERIDOPHYTES SPECIES AND THEIR MORPHOLOGICAL CHARACTERISTICS FROM THE SOUTHWEST OF SAUDI ARABIA

. The biodiversity of 11 fern populations representing nine species belonging to three families ( Aspleniaceae , Adiantaceae , and Pteridaceae ) was evaluated using morphological variations and molecular polymorphism generated by 12 ISSR primers. Substantial variations were scored in 16 morphological characters and reflected in the cluster analysis of the examined accessions based on morphological variation. In the phylogenetic relationships generated based on ISSR polymorphism and morphological variations, the three Cheilanthes species clustered with Asplenium adiantum nigrum and were delimited from other species, which supports that A. adiantum nigrum may be related to Cheilanthes species. In the meantime, the two populations of Asplenium ceterach and the two populations of Asplenium aethiopicum were differentiated as one cluster. These results are congruent with the cluster based on the analysis of ISSR data except for the association of Adiantum capillus veneris and Asplenium trichomanes , which revealed that A. trichomanes may be related to Adiantum capillus veneris . Also, these results were confirmed by the tree obtained based on the Elucedine coefficient and with the population grouping based on principal component analysis (PCA) using the PAST program. Also, Online Marker Efficiency Calculator (iMEC) supports the use of ISSR markers for examining the genetic diversity across fern genotypes.