Effects of magnesium supply level on growth, nutrient element absorption and distribution, and quality of Panax quinquefolium / 中国中药杂志

This study aims to investigate the effects of different magnesium supply levels on the growth, nutrient absorption and distribution, and quality of Panax quinquefolium, and to determine the optimum content of exchangeable magnesium in soil. Three-year-old plants of P. quinquefolium were used in this study, and eight magnesium supply gradients(CK, Mg1-Mg7) were designed for indoor pot experiment(cultivation in soil). The plant growth indexes, nutrient element content in soil and plant, and root saponin content were determined at the end of the growth period. The correlation analysis of nutrient element content in aboveground and underground parts of P. quinquefolium showed significantly negative correlations of magnesium-calcium, magnesium-potassium, and magne-sium-manganese. With the increase in magnesium supply level, the biological absorption coefficient of magnesium increased, while that of total nitrogen, potassium, iron, and manganese decreased; the biological transfer coefficient of magnesium decreased, while that of nitrogen, phosphorus, calcium, iron, and manganese increased. The saponin content was analyzed by principal component analysis, which showed the comprehensive score in the order of Mg4(2.537), Mg2(1.001), Mg3(0.600), Mg1(0), Mg7(-0.765), CK(-0.825), Mg6(-0.922), and Mg5(-1.663). The partial least squares-path modeling(PLS-PM) showed that the correlation coefficients of exchangeable magnesium and pH with quality were-0.748 and-0.755, respectively, which were significant. Magnesium-calcium, magnesium-potassium, and magnesium-manganese showed antagonism in the nutritional physiology of P. quinquefolium. Excessive application of magnesium can lead to the imbalance of nutrient elements in P. quinquefolium. The content of exchangeable magnesium in soil suitable for the quality formation of P. quinquefolium was 193.34-293.34 mg·kg~(-1). In addition to exchangeable magnesium, pH was also important to the quality formation of P. quinquefolium. Therefore, exchangeable magnesium and pH could be regarded as monitoring factors for the quality formation of P. quinquefolium.

Research progress on pesticide residues of Panax ginseng / 中国中药杂志

Panax ginseng, a perennial herb, is prone to diseases and insect pests in the growth process, which are primarily prevented and treated by pesticides. However, due to the lack of standardization in the types, frequencies, and doses of pesticides, pesticide residues have become the main exogenous pollutants of P. ginseng. To explore the risk of pesticide residues in P. ginseng, this paper summarized and analyzed the common pesticide residues in P. ginseng, detection techniques, and pesticide residue limit stan-dards based on the published literature in recent years. The results revealed that the main pesticide residues in P. ginseng were organochlorine pesticides, such as tetrachloronitrobenzene, pentachloronitrobenzene, and hexachlorobenzene, and the detection techniques were dominated by gas chromatography(GC), liquid chromatography(LC), or those combined with mass spectrometry(MS). Because of the long half-life and difficulty in degradation, organochlorine pesticides have become the main factor affecting the export of P. ginseng. It is worth mentioning that P. ginseng has been classified as food in Japan, South Korea, the European Union, and other countries, and the standards of pesticide residues and limits are stricter than those in China. The quality and safety of P. ginseng are prerequisites for the efficacy of Chinese medicine and the development of traditional Chinese medicine. The formulation of scientific and effective standards for pesticide application and limits would promote the high-quality development of the P. ginseng industry.

Research progress on pesticide residues of Panax notoginseng / 中国中药杂志

Panax notoginseng is a perennial Chinese medicinal plant, which has serious continuous cropping obstacles and is prone to a variety of diseases and insect pests during the growth process. At present, the prevention and control of pests and diseases is mainly carried out through chemical pesticides, and the consequent pesticide residues of P. notoginseng have attracted much attention. This study reviewed the types and detection methods of pesticide residues in P. notoginseng from 1981 to 2021, and compared the limits of pesticide residues in P. notoginseng in China and abroad to provide a reference for rational application of pesticides in P. notoginseng and quality control of medicinal materials, thereby promoting the sustainable development of the P. notoginseng industry in China. Currently, there are only 40 published papers on pesticide residues of P. notoginseng, which is indicative of a serious problem of insufficient research. At present, hundreds of pesticide residues in P. notoginseng can be detected simultaneously by using chromatography-tandem mass spectrometry. The pesticides detected have gradually changed from early prohibited ones, such as dichlorodiphenyl trichloroethane(DDT), benzene hexachloride(BHC), and parathion, to low toxic ones(e.g., dimethomorph, procymidone, propicona-zole, and difenoconazole). The dietary risk from pesticide residues in P. notoginseng is low, which would not cause harm to consu-mers. This study concluded that in the future, the development of the quality standard for pesticide residues of P. notoginseng should be actively carried out. To increase the pesticides used in actual production in the quality standard based on the existing ones and to guide farmers to use pesticides scientifically will be the focus of future work.