[Mini-barcode combined with ITS2 for identification of bulk Artemisiae Scopariae Herba]

Artemisiae Scoporiae Herba is derived from Artemisia scoparia or A. capillaris. The accurate identification of the herbs, particularly when dealing with bulk samples, is critical for ensuring the quality and efficacy of the medicinal product. This study aimed to establish a comprehensive molecular approach by combining multiple markers for the precise identification of Artemisiae Scoporiae Herba. The ITS2 from A. scoparia, A. capillaris, and other common Artemisia species were retrieved from GenBank. MEGA was used to build a phylogenetic tree with these sequences, and the effectiveness of ITS2 in species identification was assessed. The analysis revealed that while ITS2 could distinguish Artemisiae Scoporiae Herba from other closely related species of Artemisia, it was insufficient to differentiate between A. scoparia and A. capillaris. To address this limitation, the chloroplast genome of A. capillaris was assembled and compared with the published chloroplast genomes of A. scoparia and A. capillaris, on the basis of which a DNA mini-barcode was developed. The rpoA-rps11 region was selected as the target for the development of mini-barcode due to its potential for distinguishing between these two species. Specific primers were designed to differentiate A. scoparia from A. capillaris. The ITS2 sequences and the newly developed mini-barcode were used together for Sanger sequencing to identify individual samples of Artemisiae Scoporiae Herba, while DNA metabarcoding was employed for the identification of bulk samples. The identification results of representative individual samples and bulk samples from different regions consistently confirmed A. capillaris. This study established a method that combined ITS2 and mini-barcode to identify bulk samples of Artemisiae Scoporiae Herba from different regions. This approach overcomes the limitations of morphological and chemical methods, enhancing species identification accuracy and supporting a stable supply of medicinal materials.