The Crassulaceae family displays extensive morphological diversity and complex evolutionary trajectories across its constituent genera. These attributes significantly challenge the reconstruction of intrafamilial phylogenetic relationships. While chloroplast and nuclear DNA markers are widely used for phylogenetic analyses, mitochondrial DNA (mtDNA) remains underutilized, despite its demonstrable potential as a taxonomic marker. Sequence variation in the mitochondrial nad7 intron was analyzed across six species representing two genera (Phedimus and Sedum) native to Korea. The objective was to assess genetic diversity and determine whether the nad7 intron could effectively augment existing chloroplast and nuclear DNA markers as a taxonomic tool. Target amplicon length spanned 974 to 998 base pairs (bp). Multiple sequence alignment of the six Crassulaceae species from Phedimus and Sedum identified single nucleotide polymorphisms (SNPs), insertions/deletions (INDELs), and dinucleotide polymorphisms, interspersed with conserved nad7 intron regions. Interestingly, an INDEL at positions 189–192 exhibited a diagnostic genus-level pattern, facilitating the unambiguous separation of Phedimus and Sedum. This outcome is consistent with established morphological and chloroplast DNA–based classifications. Collectively, these findings validate the mitochondrial nad7 intron as a promising supplementary molecular marker for taxonomic classification and genetic resource conservation within Crassulaceae.

Morus Folium (Sang-yeop in Korean) is one of the most important Oriental medicinal plants. In Korea, both M. alba and M. cathayana are regarded as the botanical sources for Morus Folium. In order to discriminate M. alba and M. cathayana from their adulterant, M. tricuspidata, mitochondrial NADH dehydrogenase subunit 7 (nad7) intron 2 region was targeted for molecular analysis with universal primers. DNA polymorphisms, including SNP sites, insertions, and deletions, were detected among these three species sequencing data. Based on these DNA polymorphisms, specific primers were designed for the three species respectively. Multiplex PCR was conducted for molecular authentication of M. alba, M. cathayana, and M. tricuspidata with specific primers. The present results indicate that it is possible to identify Morus Folium from its adulterant using mitochondrial nad7 intron 2 region. The established multiplex-PCR system was proved to be effective for identification of Morus Folium. The results indicate that mitochondrial introns can be used for inter-specific polymorphic study, and the described method can be applied for molecular identification of medicinal materials.