Investigating hybridization and variability between Ficus species in Saudi Arabia through DNA barcoding approach and morphological characters

摘要

Recently, research interest has spread through the DNA barcoding for economically important species of plants. In this work, the morphological characterization and DNA barcoding were investigated to discriminate between Ficus carica, Ficus cordata and Ficuspalmata inhabiting Taif highlands to show the possibility of hybridization between them. F. carica L. (cultivated tree) and F. palmata Forssk. (wild tree) showed great morphological similarities that reflected a probable interspecific hybridization between them. The observed hybrids were of low commercial importance. The obtained results of DNA barcodes (ITS, matK, rbcL and trnH) exposed different evolutionary events between the four regions, allowing each other to complement the discrimination between Ficus species. The phylogenetic trees revealed excess genetic diversity and distinguished Ficus species inhabiting Taif from other species retrieved from the GenBank proving their endemism to flora of Saudi Arabia. Transition/transversion bias (R) and rate of Tajima evolution for rbcL, trnH-psbA and ITS showed that the rate of evolution of Ficus species relatively accelerates and enhances hybridization between them. Entomorphology seemed to play an important role in hybridization and causing notable genetic diversity between F. carica and F. palmata in Taif. ITS was suggested as a plant barcode for its discriminatory power at low taxonomic levels than plastid barcodes.