[Research progress in quality of understory cultivated Chinese medicinal herbs]

Understory ecological cultivation of Chinese medicinal herbs is a crucial component of China's national strategy for developing forest-based economies, yet it frequently faces challenges such as low yields and high production costs. This review synthesizes comparative studies on the active constituent content of nine medicinal herbs-Panax ginseng, P. quinquefolius, P. notoginseng, Polygonatum, Dendrobium, Paris polyphylla, Coptis chinensis, Bletilla striata, and Epimedium-between understory cultivation and field cultivation. The findings indicate that Dendrobium in understory cultivation systems generally exhibit higher levels of polysaccharides than greenhouse-grown counterparts. For C. chinensis, alkaloid content shows no significant difference between understory cultivation and shaded field cultivation. Extended growth periods enable P. ginseng and P. quinquefolius to achieve total and rare ginsenoside concentrations surpassing those of short-cycle cultivated counterparts. The quality of Polygonatum, P. notoginseng, P. polyphylla, and B. striata is influenced by forest stand type and shade intensity, with no clear patterns yet established. Flavonoid accumulation in Epimedium is sensitive to canopy closure, exhibiting an optimal light-intensity range. Moreover, understory cultivation enhances soil microbial diversity and reduces the abundance of certain phytopathogens, suggesting potential ecological pest/disease-suppression effects, although direct evidence regarding pest/disease incidence rates and agrochemical residues remains lacking. Overall, the impact of understory cultivation on medicinal herb quality is species-specific and environmentally contingent, with quality advantages likely arising from moderate abiotic stress, extended growth duration, and enhanced biodiversity. Future research should standardize experimental designs, quantify key ecological factors, and deepen mechanism understanding of forest-medicinal herb interactions to support high-quality industry development.