DNA Barcoding for Identification and Traceability in the Entire Industrial Chain of Lonicerae Japonicae Flos

As a traditional medicinal plant in China, Lonicerae Japonicae Flos (LJF) is extensively used in traditional Chinese medicine and Medicine Food Homology products, supporting a well-established industrial chain with diverse applications. However, the entire industrial chain is persistently compromised by adulteration with adulterants such as Lonicerae Flos (LF). Because LJF and LF are highly similar in appearance, misidentification can occur in trading and processing, and the substantial price gap of ¥94.0/kg for LJF, and ¥31.5/kg for LF, further increases incentives for substitution. Here, analytical approaches including morphological observation, DNA barcoding, and mini-barcode were integrated to identify 94 samples in the entire industrial chain, which included seeds, leaves, flower buds, decoction pieces, and traditional Chinese patent medicines (TCPMs). A total of 19 adulterants were detected among 72 commercial samples, including eight in 10 seed samples, two in 14 flower bud samples, four in 25 decoction pieces samples, and five in 23 TCPM samples. Morphological observation allowed efficient preliminary screening of upstream samples but was unsuitable for deeply processed products. Universal DNA barcoding could be used to identify diverse species, but DNA degradation compromised sequencing success in heavily processed materials. By comparison, mini-barcode achieved high identification efficiency for the heavily processed samples. These findings provided technical support for a quality assurance framework for the LJF industry. The framework could provide practical guidance for market regulation authorities and industry stakeholders to strengthen supplier auditing, batch release testing, and traceability from cultivation to the market.