DNA barcoding for species identification and phylogenetic investigation employing five genetic markers of Withania coagulans

Abstract

Withania coagulans is an important medicinal plant in India, dispersed from the East Mediterranean to South Asia, but W. coagulans is usually misidentified with other Withania species. Accurate identification of medicinally important plant species is helpful for their effective use in medicine and would help to protect the globally declining threatened or endangered plants. The present study aimed to create barcodes for W. coagulans using five genetic markers (rbcl, matK, ITS, psbA-trnH, and rpoB-trnCGAR) from two samples of W. coagulans collected at ICAR-Anand and the Institute of Science, Mumbai, to test the discrimination capacity of the plant DNA barcode. The study findings confirmed that psbA and rbcl are better barcodes for investigating W. coagulans, which displayed 100% conservation even when geographical sites were changed, whereas the genetic loci rpoB, ITS, and matK helped to distinguish between the distinct evolutions of the Solanaceae family. ITS showed the highest GC content, 66.9% for WCNB1 and 62.6% for WCNB2. The maximum likelihood rpoB marker gave the highest probability value (–889.38), followed by rbcl (–967.83) compared to other genetic markers. The study conclusions would be used in the pharmaceutical sector to develop DNA-based species identification of the W. coagulans plant to point out adulteration while plant collection. The work provides insights into molecular-based identification and authentication of W. coagulans.