[Resource components and utilization values of different parts of Panax quinquefolium in Shandong province].

To explore the resource components and availability of different parts of Panax quinquefolium in Shandong province, the paper employed the non-targeted metabolomics technology based on ultra-high performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS) to analyze the metabolites and their metabolic pathways in the root, fibril, stem, and leaf of P. quinquefolium. The content of seven ginsenosides and polysaccharides in different parts was determined by high performance liquid chromatography(HPLC) and ultraviolet-visible spectrophotometry(UV-Vis). The results showed that the metabolites were mainly sugars, glycosides, organic acids, amino acids and their derivatives, terpenoids, etc. The total abundance of metabolites followed the trend of leaf > root > fibril > stem. Most of the differential metabolites were concentrated in phenylpropane biosynthesis, flavonoid biosynthesis, citric acid cycle, and amino acid biosynthesis. The leaf contained high levels of sugars, glycosides, amino acids and their derivatives, and flavonoids; the root was rich in terpenoids, volatile oils, vitamins, and lignin; the fibril contained rich organic acids; and the stem had high content of nucleotides and their derivatives. The content of ginsenosides Re and Rb_1 was significantly higher in the root; the content of ginsenosides Rg_1, Rg_2, Rd, F_(11), and polysaccharide was significantly higher in the leaf; and the content of ginsenoside Rb_2 was significantly higher in the stem. We analyzed the resource components and availability of different parts of P. quinquefolium, aiming to provide basic information for the comprehensive development and utilization of P. quinquefolium resources in Shandong province.

[Diversity of arbuscular mycorrhizal fungi of Panax quinquefolius cultivated in Shandong province].

In this study, the colonization, diversity and relative abundance of arbuscular mycorrhizal fungi(AMF) in the roots of Panax quinquefolius in different habitats of Shandong province were analyzed by staining-microscopy and high-throughput sequencing. The data were analyzed by bioinformatics tools and statistical software. The results showed that the roots of P. quinquefolius in different habitats were colonized by AMF with different rates and intensities. The AMF in roots of P. quinquefolius belong to three genera, three families, three orders, one class and one phylum. At the level of order, the AMF mainly included Paraglomerales(52.48%), Glomerales(25.60%) and Archaeosporales(3.08%). At the level of family, the AMF were dominated by Paraglomeraceae(52.48%), Glomeraceae(18.94%) and Claroideoglomeraceae(3.05%). At the level of genus, Paraglomus(51.46%), Glomus(20.01%) and Claroideoglomus(3.52%) accounted for a large proportion, of which Paraglomus and Glomus were dominant. Cluster analysis showed that the AMF in roots of P. quinquefolius with close geographical locations could be clustered together. In this study, the diversity and dominant germplasm resources of AMF in roots of P. quinquefolius cultivated in the main producing areas were identified, which provi-ded basic data for revealing the quality formation mechanism of P. quinquefolius medicinal materials from the perspective of environment.

[Research progress on application of biochar in cultivation of agriculture and Chinese materia medica].

Biochar is a kind of solid material with high aromatization and rich in carbon, which is formed by pyrolysis of biomass at high temperature(250-700 ℃) under anoxic or hypoxic conditions. It has the characteristics of large specific surface area and rich pores. In recent years, as a good soil conditioner, biochar has gradually improved its advantages in improving soil rhizosphere micro ecological environment, promoting plant growth and development, and enhancing plant resistance, etc. It has been proved that biochar can affect the growth and development of plants by improving soil physical and chemical properties, adjusting microbial community structure, participating in the metabolic process in plants, and inducing plants to enhance resistance. This paper summarized the research progress of biochar application in agriculture and introduced the ecological effects and mechanism of biochar on plant seed germination, seedling growth, crop yield and stress resistance. Combined with the characteristics of Chinese materia medica, this paper expounds the application potential of biochar in improving the content of secondary metabolites of Chinese materia medica and alleviating continuous cropping obstacles of Chinese materia medica, etc. In the future, it is necessary to strengthen the research of biochar in the biosynthesis of secondary metabolites, allelopathy and heavy metal stress of medicinal plants, so as to provide reference for the application of biochar in the cultivation of Chinese materia medica.

[Preliminary investigation on arbuscular mycorrhiza fungi of cultivated Panax quinquefolium roots].

In this study, the infection of root arbuscular mycorrhizal fungi(arbuscular mycorrhizal fungi, AMF of Panax quinquefolium in Shandong province was investigated, and the distribution characteristics and infection regularity of AMF were found out. The AMF of P. quinquefolium roots in different habitats was examined by alkali dissociation-trypickin blue staining method to study the infection rate and infection intensity. The contents of ginsenoside(Rb_1, Re, Rg_1, Rb_2, Rd and Rh_1) in the roots of P. quinquefolium was determined by HPLC. The experimental data were SPSS 17.0 statistical software for One-way analysis of variance, cluster analysis and correlation analysis. The results showed that the AMF infection in roots of P. quinquefolium, and there were obvious structures such as hyphae, arbuscular branches and vesicles, and the AMF infection rate and infection intensity showed obvious spatial and temporal heterogeneity with the growth age and origin of P. quinquefolium. The infection rate of AMF in roots of P. quinquefolium from 1 to 3 years increased significantly with the increase of growth years(P<0.05). The infection intensity and infection rate of P. quinquefolium showed a similar change trend, the AMF infection rate and infection intensity reached the highest level in the third year. Cluster analysis showed that the infection rates of roots of P. quinquefolium in similar geographical locations could be clustered together. Correlation analysis showed that the AMF infection rate of P. quinquefolium root was significantly positively correlated with the infection intensity, and the AMF infection rate and infection intensity were significantly positively correlated with the contents of ginsenoside Rg_1, Re and Rb_1. This study explored the distribution characteristics and regularity of AMF in roots of P. quinquefolium under the protected cultivation conditions, and provided basic data for ecological cultivation of P. quinquefolium and research and development of biological bacterial fertilizer.

Postharvest UV-B Irradiation Stimulated Ginsenoside Rg1 Biosynthesis through Nitric Oxide (NO) and Jasmonic Acid (JA) in Panax quinquefolius Roots.

The study highlights the influence and signal transduction mechanism of postharvest UV-B on the production of Rg1 in Panax quinquefolius roots during the drying process. The results showed that postharvest UV-B irradiation induced generation of nitric oxide (NO), jasmonic acid (JA), and ginsenoside Rg1 of P. quinquefolius roots. The UV-B-induced increase of Rg1 was suppressed by NO-specific scavenger (cPTIO) and NOS inhibitors (PBITU), JA synthesis inhibitor (SHAM), and JA synthesis inhibitor (PrGall), indicating that NO and JA played essential parts in UV-B-induced Rg1. External NO inhibitors treatment inhibited UV-B-induced accumulation of NO and JA, which suggested that NO was located upstream of the JA signal pathway. NO-caused Rg1 was inhibited by SHAM and PrGall, implying JA participated in transmitting signal NO to Rg1 accumulation. In other words, NO mediated the postharvest UV-B-induced Rg1 accumulation by the JA-dependent pathway in P. quinquefolius roots during the drying process, which helps us understand the underlying mechanisms involved in UV-B-induced Rg1 production and provides information helpful for P. quinquefolius production.