Molecular and phytochemical variability among genus Albizia: a phylogenetic prospect for future breeding

Fabaceae, the third-largest Angiosperm family, exhibits great morphological diversity with significantly high species diversification rate. Albizia, one of the largest genera of the legume family, possesses high ecological, economical and medicinal application prospects and displays a global distribution. The taxonomic classification among Albizia remains, however, unclear and has been subjected to changes. The resolution of phylogenetic relationships among members of genus Albizia is a priority. Nine Albizia species cultivated in Egypt; Albizia lebbeck, A. julibrissin, A. odoratissima, A. procera, A. anthelmintica, A. guachapele, A. myriophylla, A. richardiana and A. lucida were subjected to molecular classification via DNA fingerprinting techniques viz. Inter Simple Sequence Repeat (ISSR) and Start Codon Targeted polymorphism (SCoT) using ten primers, five for each technique. The total number of bands produced by ISSR and SCoT primers was 28 and 40, respectively. The percentage of polymorphism varied from 64.28% in ISSR to 67.50% in SCoT analysis. Additionally, chemotaxonomic analysis was implemented based on UV spectroscopic profiling and total phenolic content coupled to unsupervised chemometric tools; Principal Component Analysis (PCA) and Hierarchical Cluster Analysis (HCA). Interspecific relationships were confirmed via molecular and phytochemical analyses between A. procera and A. guachapele; A. lebbeck and A. odoratissima; and A. julibrissin and A. lucida. The study reveals that chemotaxonomic data can reflect phylogenetic relationships among examined Albizia species and provides insights to the significance of utilizing the strengths of both molecular taxonomy and chemotaxonomy to resolve phylogenetic relationship among this genus which offers baseline for breeding programs. Future strategies to enrich taxonomic classification among Albizia includes extensive morphological characterization, DNA barcoding techniques and metabolomic profiling.