In silico analysis of a chloroplast loci for DNA barcoding of Aloe spp.

In silico chloroplast DNA barcoding of Aloe spp.

Abstract

DNA barcoding has emerged as a reliable tool for species identification, especially in taxonomically complex plant groups such as the genus Aloe. This study employed an in-silico approach to evaluate the efficacy of the rbcL gene locus as a DNA barcode for 20 Aloe species. A total of 70 high-quality sequences linked to voucher specimens were retrieved from GenBank, manually curated to a uniform length of 480 base pairs, and analyzed using multiple sequence alignment and phylogenetic methods. The evolutionary divergence within and among species was estimated using p-distance metrics, revealing high sequence conservation across most Aloe species. Phylogenetic analysis using the Neighbor-Joining method demonstrated that 12 species (60%) formed well-supported monophyletic clades, confirming the rbcL locus's moderate resolution capacity. Species such as A. vera, A. lineata, and A. maculata clustered tightly with high bootstrap values, while few closely related species remained unresolved. The findings suggest that the sample size and incorporating multi-locus analyses will further improve species identification and evolutionary understanding within the genus.