GENETIC RELATIONSHIPS AMONG WILD SPECIES OF SUBFAMILY MALVOIDEAE IN SAUDI ARABIA AS INFERRED FROM SCoT AND ISSR MARKERS

Genetic investigation and phylogenetic analyses of 21 species, representing 8 genera of the subfamily Malvoideae from Saudi Arabia, were carried out by using Start Codon Targeted (SCoT), Inter Simple Sequence Repeats DNA (ISSR), and combined ISSR and SCoT markers. Ten SCoT and five ISSR primers created 138 polymorphic amplified fragments, which pointed to a comparatively high level of genetic difference in Malvoideae. SCoT markers exposed a higher level of polymorphism (89 bands) than ISSR (49 bands). The comparison of SCoT and ISSR based dendrograms revealed significantly similar grouping patterns of genotypes. Five clusters and clades were documented within Malvoideae, which generally verified traditional groupings with a few exceptions. Taxonomic and phylogenetic results were discussed in contrast to existing morphological and phylogenetic data. The results of this study provided useful data for evaluating the taxonomy of two Malvoideae tribes at infrageneric and subgeneric levels. In general, the results are consistent with the previous phylogenetic findings of the polyphyletic nature of Abutilon, Hibiscus, and Malva. The species of sections Bombicella and Malva were highly heterogeneous. The most exciting result of this analysis was identifying the Senra incana with unique characters suggesting that it should be preserved as a separate tribe. Similarly, distinctive genetic profiles between the closely related genera Fioria and Althaea were also noted suggesting that they should be placed in different tribes. Furthermore, the present results also indicated parallel characters among the species of Pavonia that supports the monophyly of this genus.