Genetic and Molecular Evolutionary Analysis of Iraqi Figs Using ITS Sequences Compared to some International Cultivars

Abstract

     This study aimed to investigate the genetic variability and molecular evolution of Iraqi figs (Ficus carica L., family Moraceae) compared to some worldwide reference sequences. Upon internal transcribed spacer (ITS) sequence data analysis, the results indicated variation in the guanine-cytosine content (GC-content) ranging from 61.83% to 64.52%, with an average of 63.34%. Transitions seemed to occur less frequently than transversions in this region, where the overall bias R for transition/transversion has been calculated to be 0.551. Eight haplotypes have been identified from the 17 matched reference sequences under study, and the aligned sequences associated with the ITS allowed us to identify 64 polymorphic sites, 60 of which were singleton variables and 4 of which were parsimony- informative. A random distribution independent of provenance was observed in overall fig accessions in the neighbour-joining (NJ) tree. Argentine, Tunisian, and United Kingdom (UK) figs have the most genetic diversity (substitution), with a divergence distance of 0.05. This finding was further supported by principal components analysis (PCA) and the haplotype network. The first three of the PCA described 64.36% of the total variance. Molecular evolution tests revealed that the worldwide figs had demographic expansion under a perfectly neutral model in a population that was in equilibrium until the 9^th generation.