Phenotyping elucidates the association between traits and bioactive components in Notopterygium incisum

Natural products enriched in medicinal plants have broad prospects in addressing global public health challenges and meeting diverse human health needs. The traditional Chinese herbal medicine Notopterygii Rhizoma et Radix (NRR) is the dried rhizome and root of Notopterygium incisum Ting ex H. T. Chang, which is used to treat wind-cold-caused headaches, rheumatic disease, osteoarthritis, and anti-thrombotic treatment. Commonly, NRR collected from wild collection faces the issues of resource depletion and unstable quality.

In this study, we investigated the phenotypical traits and bioactive components in the wild collected individuals of N. incisum to find and conserve the excellent germplasm. Results showed that the genetic diversity of N. incisum is rich and led to the high variation of the phenotypic traits, e.g., aboveground traits with coefficient of variation (CV) ranged from 21.3% ~ 55.5% and reproductive growth traits ranged from 34.7% to 90.5%, and bioactive pharmaceutical components, e.g., notopterol ranging from 0.02% to 1.27% and isoimperatorin ranging from 0.16% to 3.32%. According to the variation in bioactive pharmaceutical components, N. incisum was divided into three groups: high-quality, medium-quality, and low-quality group. The bioactive pharmaceutical components isoimperatorin and notopterol peaked at 2.38%, 0.83% in the high-quality group; in contrast, the lowest isoimperatorin and notopterol at 0.69% and 0.33% were obtained in the low-quality group. The Mantel test showed that basal leaf petiole length (r = 0.187, p < 0.05) and basal leaf width (r = 0.107, p < 0.05) were significantly affected by genetic diversity, which contributed to germplasm identification.

This study integrates phenotypic characterization with chemical analysis to investigate the correlations between key traits and bioactive compounds in N. incisum. The high-quality group was characterized by robust vegetative growth and weak reproductive growth, while the low-quality group showed the opposite. The current research provides a potential practical reference method for screening high-quality germplasm resources of N. incisum. That is, the quality of N. incisum germplasm resources can be distinguished based on the strength of reproductive growth ability.