Developing evidence-based uses of herbal medicines and natural product-based drug discovery are two core aims of ethnopharmacology. This requires an understanding of the medicinal plants and the traditional medical knowledge associated with them which is a basis for cross-cultural comparison. The botanical drugs of traditional medical systems are still not understood well, even for well-known and widely respected traditions like Ayurveda. In this study, a quantitative ethnobotanical analysis was performed on the single botanical drugs included in the Ayurvedic Pharmacopoeia of India (API), presenting an overview on the medicinal plants of Ayurveda from perspectives of plant systematics and medical ethnobotany. Part-I of API includes 621 single botanical drugs, which are sourced from 393 species (323 genera in 115 families). Of these, 96 species yield two or more drugs, together accounting for 238 drugs. Taking the traditional concepts, biomedical uses and the pragmatic disease classification into account, therapeutic uses of these botanical drugs are sorted into 20 categories, which meet primary health demands. The therapeutic uses of the drugs sourced from the same species may differ considerably, but 30 of the 238 drugs are used in highly similar way. The comparative phylogenetic analysis identifies 172 species with high potential for specific therapeutic uses. This medical ethnobotanical assessment for the first time provides a comprehensive understanding on the single botanical drugs in API from the perspective of medical botany using an “etic” (scientist-oriented) approach. This study also highlights the importance of quantitative ethnobotanic methods in understanding traditional medical knowledge.

The volatile compounds produced by plants play an important role in plant growth, plant communication, and resistance to biological and abiotic stresses. Astragalus membranaceus var. mongholicus (AM) is a perennial herbaceous plant (Leguminosae) that is widely cultivated in northwest China. The bioactive compounds in its root have shown various pharmacological activities. Root rot disease caused by Fusarium spp. often occurs in AM planting with increasing severity in continuous monoculture. It is currently still unclear what are the effects of the volatile compounds produced by fresh AM on itself, other crops cultivated on the same field after AM, pathogen, and rhizobia. In this study, we found that seed germination and seedling growth of AM, lettuce (Lactuca sativa L.), and wheat (Triticum aestivum L.) could be affected if they were in an enclosed space with fresh AM tissue. Additionally, 90 volatile compounds were identified by SPME-GC-MS from whole AM plant during the vegetative growth, 36 of which were specific to aerial parts of AM (stems and leaves, AMA), 17 to roots (AMR), and 37 were found in both AMA and AMR. To further identify the allelopathic effects of these volatile compounds, five compounds (1-hexanol, (E)-2-hexenal, (E,E)-2,4-decadienal, hexanal, and eugenol) with relatively high content in AM were tested on three receptor plants and two microorganisms. We found that (E,E)-2,4-decadienal and (E)-2-hexenal showed significant inhibitory effects on the growth of AM and lettuce. One-hexanol and hexanal suppressed the growth of wheat, while eugenol showed a similar effect on all three plant species. Moreover, the activities of these compounds were dose dependent. Notably, we discovered that (E)-2-hexenal and eugenol also inhibited the growth of the pathogen Fusarium solani by as high as 100%. Meanwhile, all five compounds tested suppressed the rhizobia Sinorhizobium fredii. In summary, this study furthered our understanding of the comprehensive allelopathic effects of the main volatile components of AM.

American ginseng (Panax quinquefolius) is an important medicinal plant cultivated in China since the 1980s. Its dried roots are used for food, health care products, and medicine in China (Yuan et a...

The replant problem is a widespread challenge in agricultural production and results in significant financial losses. The survival and development of American ginseng ( Panax quinquefolius L.), a well-known perennial medicinal plant, also typically suffer from replant problems. At present, efficient strategies for this issue and the underlying mechanisms are still lacking. Here, a series of in situ field experiments over a 4-year period were conducted to investigate the effectiveness and possible mechanisms of soil fumigation and fungicide in improving American ginseng survival under continuous cropping. During the 4-year ginseng cultivation, the seedling emergence rates in the dazomet fumigation-treated group (DF) decreased from 90.67% to 52.92%, from 78.67% to 0% in the lime sulfur fungicide-treated group (LS), and from 66.67% to 0% in the control. The fresh root weight in DF increased from 0.36 to 28.72 g, from 0.32 to 13.74 g in LS, and from 0.42 to 9.06 g in the control for the first 2 years. However, no ginseng survived during the following 2 years. Moreover, DF significantly decreased root rot disease incidence by 55.55% compared to LS-treated soil and 69.39% compared to non-treated soil. The correlation analysis results showed that both diversity and structure indices of bacteria and fungi were significantly correlated with root biomass and disease incidence in the second year. In summary, DF has presented a significant beneficial effect on American ginseng development. Additionally, the second year is the critical period to shape the soil microbial community, which could have a long-lasting effect on the development of American ginseng. IMPORTANCE: Numerous reports of soil fumigants and fungicides on annual crops exist; however, it is unclear whether the single application to perennial plants persistently improves plant growth and controls disease or whether it has a long-lasting impact on soil microbes. We found that soil fumigation enhances ginseng growth and suppresses root rot disease by reshaping the soil microbial community. Our findings benefit the agricultural development of ginseng and provide a theoretical basis for the prevention of ginseng diseases.