Untargeted GC-MS and FT-NIR study of the effect of 14 processing methods on the volatile components of Polygonatum kingianum.

Introduction: Polygonatum kingianum is a traditional medicinal plant, and processing has significantly impacts its quality. Methods: Therefore, untargeted gas chromatography-mass spectrometry (GC-MS) and Fourier transform-near-infrared spectroscopy (FT-NIR) were used to analyze the 14 processing methods commonly used in the Chinese market.It is dedicated to analyzing the causes of major volatile metabolite changes and identifying signature volatile components for each processing method. Results: The untargeted GC-MS technique identified a total of 333 metabolites. The relative content accounted for sugars (43%), acids (20%), amino acids (18%), nucleotides (6%), and esters (3%). The multiple steaming and roasting samples contained more sugars, nucleotides, esters and flavonoids but fewer amino acids. The sugars are predominantly monosaccharides or small molecular sugars, mainly due to polysaccharides depolymerization. The heat treatment reduces the amino acid content significantly, and the multiple steaming and roasting methods are not conducive to accumulating amino acids. The multiple steaming and roasting samples showed significant differences, as seen from principal component analysis (PCA) and hierarchical cluster analysis (HCA) based on GC-MS and FT-NIR. The partial least squares discriminant analysis (PLS-DA) based on FT-NIR can achieve 96.43% identification rate for the processed samples. Discussion: This study can provide some references and options for consumers, producers, and researchers.

ResNet Model Automatically Extracts and Identifies FT-NIR Features for Geographical Traceability of Polygonatum kingianum.

Medicinal plants have incredibly high economic value, and a practical evaluation of their quality is the key to promoting industry development. The deep learning model based on residual convolutional neural network (ResNet) has the advantage of automatic extraction and the recognition of Fourier transform near-infrared spectroscopy (FT-NIR) features. Models are difficult to understand and interpret because of unknown working mechanisms and decision-making processes. Therefore, in this study, artificial feature extraction methods combine traditional partial least squares discriminant analysis (PLS-DA) and support vector machine (SVM) models to understand and compare deep learning models. The results show that the ResNet model has significant advantages over traditional models in feature extraction and recognition. Secondly, preprocessing has a great impact on the feature extraction and feature extraction, and is beneficial for improving model performance. Competitive adaptive reweighted sampling (CARS) and variable importance in projection (VIP) methods screen out more feature variables after preprocessing, but the number of potential variables (LVs) and successive projections algorithm (SPA) methods obtained is fewer. The SPA method only extracts two variables after preprocessing, causing vital information to be lost. The VIP feature of traditional modelling yields the best results among the four methods. After spectral preprocessing, the recognition rates of the PLS-DA and SVM models are up to 90.16% and 88.52%. For the ResNet model, preprocessing is beneficial for extracting and identifying spectral image features. The ResNet model based on synchronous two-dimensional correlation spectra has a recognition accuracy of 100%. This research is beneficial to the application development of the ResNet model in foods, spices, and medicinal plants.

Comparison of metabolites and variety authentication of Amomum tsao-ko and Amomum paratsao-ko using GC-MS and NIR spectroscopy.

Amomum tsao-ko, as an edible and medicinal variety, has been cultivated for more than 600 years in China. Recently, two cultivars, A. tsao-ko and Amomum paratsao-ko, were found in A. tsao-ko planting area. The two cultivars are often confused because of the similar phenotype and difficult to distinguish through sensory judgment. In this study, the non-targeted gas chromatography-mass spectrometry (GC-MS) metabolomics combined with near-infrared spectroscopy (NIRS) were used for dissecting the two cultivars with phenotypic differences. According to principal component analysis (PCA) loading diagram and orthogonal partial least squares discriminant analysis (OPLS-DA) S-plot of the metabolites, the accumulation of major components including 1,8-cineole, α-phellandrene, (E)-2-decenal, (-)-ß-pinene, (E)-2-octenal, 1-octanal, D-limonene, and decanal, were present differences between the two cultivars. Seven metabolites potential differentiated biomarkers as ß-selinene, decamethylcyclopentasiloxane, (E,Z)-2,6-dodecadienal, (E)-2-hexenal, (E)-2-decenal, isogeranial, 1,8-cineole and ß-cubebene were determined. Although A. tsao-ko and A. paratsao-ko belong to the same genera and are similar in plant and fruit morphology, the composition and content of the main components were exposed significant discrepancy, so it is necessary to distinguish them. In this study, the discriminant model established by GC-MS or NIRS combined with multivariate analysis has achieved a good classification effect. NIRS has the advantages of simple, fast and nondestructive and can be used for rapid identification of varieties and fruit tissues.

[Research progress in chemical constituents in plants of Polygonatum and their pharmacological effects].

Polygonatum plants are perennial plants of Liliaceae. There are about 60 species reported at home and abroad,32 species in China,mainly distributed in the north temperate zone. Their main chemical components are steroidal saponins,polysaccharides,flavonoids,alkaloids,etc. They have anti-aging,anti-tumor,immunomodulation,antibacterial,antiviral,hypoglycemic and blood lipid effects. With the development of health industry,Polygonati Rhizome used as medicine and food has attracted great attention in recent years,and has become a research hotspot. However,the material basis of its efficacy is unclear and the product quality is uneven,which seriously limited the rapid upgrading of the industry. This review summarizes Polygonatum plants system classification,the chemical composition and pharmacological activity to provide theoretical basis for the development and utilization of Polygonatum plants.

[Study on the Genetic Relationship of Panax Notoginseng and Its Wild Relatives Based on Fourier Translation Infrared Spectroscopy].

Wild relatives play a very important role in enriching germplasm resources and improving the quality and yield of cultivated species. In this paper, the genetic relationship between Panax notoginseng and its wild relatives has been investigated by using Fourier transform infrared (FTIR) spectroscopy in order to provide theoretical bases in the variety improvement of P. notoginseng as well as the development and utilization of germplasm resources. The FTIR spectra of P. notoginseng and its wild relatives (P. japonicus var. major, P. stipuleanatus, P. vietnamensis, P. japonicus var. bipinnatifidus) as well as Panax notoginsenosides were collected. The original infrared spectra of P. notoginseng and its wild relatives were pretreated by automatic baseline correction, smoothing, ordinate normalization and second derivative. The genetic relationship between P. notoginseng and its wild relatives has been studied together with the aid of principal component analysis (PCA), partial least squares discriminant analysis (PLS-DA) and hierarchical cluster analysis (HCA). By comparing the infrared spectra of P. notoginseng with that of panax notoginsenosides, some common peaks such as 3 400, 2 930, 1 635, 1 385, 1 075 and 927 cm-1 has been found. It showed that the peak heights of P. notoginseng samples may relate with the content of panax notoginsenosides. The original infrared spectra of P. notoginseng are similar to its wild relatives and the absorption peaks of the functional groups of C­H, CO, O­H, C­N and C­O were presented. There were some differences in the fingerprint region (1 800～500 cm-1) of the second derivative spectra of these five species samples. The characteristic absorption peaks such as 1 385 and 784 cm-1 has an obviously differentiation. Then the fingerprint region of second derivative spectra is subjected to be analyzed by PCA and PLS-DA. By comparing the 3D score plots of these two methods, the classification result of PLS-DA is significantly better than PCA. In addition, the result of HCA which based on the six principal components of PLS-DA has shown that P. japonicus var. major and P. vienamensis have close relationship with P. notoginseng while P. stipuleanatus and P. japonicus var. bipinnatifidus are far from P. notoginseng. The use of Fourier transform infrared spectroscopy combined with chemometrics methods could effectively investigate the genetic relationship between P. notoginseng and its wild relatives. Furthermore, it could provide reference for the research of medicinal plants.

[Species and ecological control of disease on cultivated Gentiana rigescens in Yunnan].

OBJECTIVE: To find out variety of the fungal diseases of cultivated Gentiana rigescens and provide important basis for prevention. METHODS: The diseases were diagnosed based on field investigate, symptoms observation, pathogen isolation, determination the size of morphological and verification following the Koch's Postulate procedures. RESULTS: Anthracnose (Colletotrichum gloeosporioides), grey mould (Botrytis cinerea), brown spot (Alternaria tenuis), rust (Aecidiumpers), circular spot (Pestalotiopsis), leaf blight (Stemphylium, Ascochyta, Pleospora) and nematodes (Heterodera spp., Meloidogyne spp.) were found on Gentiana rigescens. Anthracnose was the first main disease, the diseased plant rate was over 40% and disease severity was 4 - 5 degree and second disease was rust, incidence of rate was less 10% and other diseases rate was not enough 2%. CONCLUSION: All these diseases on Gentiana rigescens are reported for the first time and Gentiana rigescens is the new host plant of the diseases.

[Correlation and path analysis on agronomic traits of Gentiana rigescens].

OBJECTIVE: The interrelation of yield and agronomic traits of Gentiana rigescens was studied for the germplasm and breeding variety of this species. METHOD: Twelve agronomic traits, root diameter, root length, root number, root biomass, stem diameter, plant height, the first branch number, leaf length, leaf width, leaf length/leaf width ratio, calyx length, and calyx number of G. rigescens from 26 wild populations in Yunnan were determined for correlation analysis, multiple stepwise regression analysis and path analysis. RESULT: Correlation analysis showed that there were significantly positive correlation between the traits of aboveground part and the length, diameter, number, and biomass of the root. Multiple stepwise regression analysis showed that length, width, and number of root, plant height, the first branch number, and the calyx number were the main factors that affected the root biomass. Path analysis showed that the diameter, length, and number of the root, the stem height, and the first branch number had a direct positive effect on the root biomass. CONCLUSION: The traits, such as high and strong stem, high number of first branch number and shrubby shape could be selected for the breeding and high yielding of G. rigescens.

[Seed germination characteristics of Gentiana rigescens].

OBJECTIVE: To investigate the influences of temperature, lightness, storage method, storage time, and gibberellin on seed germination of Gentiana rigescens. METHOD: The germination rates of G. rigescens in different treatments were observed. RESULT AND CONCLUSION: The most suitable temperature for the seed germination was 25 degrees C, at which the germination rate was 76.33%. The effect of lightness on the seeds was significantly; the germination rate of the seed was very low. Under the natural condition, the best storage method was dry storage (within 6 months), which could promote the after-ripening of the seed. 100-1 000 mg x L(-1) gibberellic acid could significantly reduce the seed germination time, and 500 mg x L(-1) gibberellic acid increased the germination rate of the seed to 95.00%.

[Breeding strains of Panax notoginseng by using EST-SSR markers].

OBJECTIVE: To comparatively determine the genetic variation and differentiation of different breeding strains of Panax notoginseng for providing the basic information for genetic breeding. METHOD: The genetic diversity and genetic structure of the 17 breeding strains of P. notoginseng were assayed by using EST-SSR molecular marker. RESULT: A total of 136 polymorphic loci of EST-SSR were detected in the 17 breeding strains of P. notoginseng, with the PIC (polymorphism information content) being 0.78, H (the gene diversity within population) being 0.139, the I (the Shannon's information index) being 0.208. Gst (coefficient of gene differentiation) was 0.382 among the 17 strains. The cluster analysis of genetic similarity showed that the 17 strains of P. notoginseng and P. stipuleanatus were classified into 4 groups, while the 17 strains of P. notoginseng were classified into three subgroups. CONCLUSION: The genetic differentiation was detected among the 17 strains of P. notoginseng from the same cultivation population by bulk selecting. And it was feasible to detect the effect of bulk selection by EST-SSR markers.