Development of Specific barcodes for identification of Aloe species based on chloroplast DNA barcoding

DNA barcoding is currently an effective and extensively used tool for species identification. The chloroplast matK (maturase K) and rbcL (Ribulose-bisphosphate large subunit) are one of the most variable coding genes of angiosperms and have been recommended as a universal barcode for land plants. Aloe is a large genus of around 500 species, and most species are widely used for traditional medicinal purposes worldwide, viz., Aloe vera, Aloe ferox, Aloe arborescens, and Aloe maculate. This study evaluated the two chloroplast DNA barcodes (matK and rbcL) to develop a theoretical base for species identification and germplasm conservation of Aloe species. The Maximum Parsimony analysis was conducted to study the evolutionary relatedness of Aloe sequences using matK and rbcL sequences retrieved from the NCBI database. The results revealed that 49 Aloe accessions were segregated into four major clades based on the matK sequence. Likewise, the 29 Aloe accessions were distributed into two major clades based on the rbcL sequence. SNP (Single Nucleotide Polymorphism) site analysis was conducted to obtain the specific barcode of Aloe species and generate the corresponding DNA QR code that electronic devices could immediately recognize. This study provides innovative research methods for efficient species identification of the genus Aloe and indicates the possibility of correctly identifying, discriminating, and documenting the Aloe species.