This study investigated the interspecific relationships among 29 Dendrobium species using electrochemical fingerprinting techniques. Differential pulse voltammetry was employed to record species-specific electrochemical profiles in both phosphate buffer solution (PBS) and acetic acid buffer solution (ABS). Distinct voltammetric patterns were observed for each species, with ABS yielding higher peak currents compared to PBS. On average, peak currents in ABS were 37.2 % ± 5.8 % higher than in PBS across all species. For example, D. nobile showed a peak current of 12.3 μA in ABS compared to 8.9 μA in PBS, a 38.2 % increase. Normalized two-dimensional plots of the electrochemical fingerprints served as unique signatures for species differentiation. Cluster analysis of the electrochemical data revealed phylogenetic relationships largely consistent with previous molecular studies, while also highlighting novel groupings. For instance, D. parishii and D. pulchellum formed separate branches, indicating distant relationships with other species. Common species such as D. officinale, D. nobile, D. primulinum, and D. loddigesii clustered together, confirming their close relationships. Interestingly, species from Sect. Dendrobium showed mixed clustering with species from four other sections, reflecting the genus's complex evolutionary history. While some inconsistencies with previous molecular phylogenetic studies were noted, such as the distant relationship between D. parishii and D. anosmum, the overall congruence between electrochemical and molecular data validates the potential of this approach. This study demonstrates that electrochemical fingerprinting, combined with appropriate data analysis techniques, can provide valuable insights into the taxonomic relationships and chemical diversity of Dendrobium species, offering a complementary tool to traditional morphological and molecular methods for plant systematics and conservation efforts.
Read full abstract