Visualizing the spatial distribution and alteration of metabolites in continuously cropped Salvia miltiorrhiza Bge using MALDI-MSI / 药物分析学报

Salvia miltiorrhiza Bge(SMB)has long been used in traditional Chinese medicine to treat cardiovascular and cerebrovascular diseases.Growing clinical usage has led to a huge demand for artificial planting of SMB.Thus,continuous cropping of SMB is an important challenge that needs to be addressed.Contin-uous cropping can alter the metabolic profile of plants,resulting in poor growth and low yield.In this study,we tried to image the spatial location and variation of endogenous metabolites in continuously cropped SMB using matrix-assisted laser desorption/ionization mass spectrometry imaging(MALDI-MSI).Spatially resolved expressions of tanshinones,salvianolic acids,polyamines,phenolic acids,amino acids,and oligosaccharides in normal and continuously cropped SMB roots were compared.The ex-pressions of dihydrotanshinone Ⅰ,tanshinone Ⅱ A,dehydromiltirone,miltirone,dehydrotanshinone ⅡA,spermine,salvianolic acid B/E,tetrasaccharide,and pentasaccharide in continuously cropped SMB roots were much lower than those in normal roots.There was little difference in the expressions of caffeic acid and salvianolic acid A in normal and continuously cropped SMB roots.Ferulic acid was more widely distributed in xylem of normal SMB but strongly expressed in xylem,phloem,and cambium of continuously cropped SMB.The spatially resolved metabolite information enhances our understanding of the metabolic signature of continuously cropped SMB and also provides insights into the metabolic ef-fects of continuous cropping in other plants.

Rhizosphere Exudate-mediated Synergistic Harm of Soil Microorganisms to Medicinal Plants in Continuous Cropping / 中国实验方剂学杂志

Continuous cropping obstacle is the bottleneck of medicinal plant cultivation, which seriously affects the quality and yield of medicinal materials. The research on the mechanism of continuous cropping obstacle has evolved from soil physical and chemical properties and allelopathy in the 1970s to the changes of rhizosphere microenvironment and plant response mechanism at present. According to the available studies in this field and our previous research work, we systematically analyzed the mechanism of rhizosphere exudate-mediated microbial community reconstruction in the soil of the medicinal plants in continuous cropping. Specifically, rhizosphere exudates, providing the carbon source and energy for microbial growth, act as inducers or repellents to induce microbial growth or transfer, thereby changing the physicochemical properties (such as acidity) of rhizosphere soil and further altering the structure of rhizosphere microbial community. Further, we comprehensively discussed the ways of synergism between rhizosphere exudates and soil microorganisms in causing harm to the medicinal plants in continuous cropping. That is, rhizosphere exudates mediate the infection of the rhizosphere by pathogenic microorganisms, increase the susceptibility of the nearby plants, inhibit the defense of the host plants, and protect the pathogens to occupy the dominant niche. The synergistic interaction results in the release of more pathogenic factors such as mycotoxins by rhizosphere pathogens, enhanced toxicity of rhizosphere allelochemicals, and deterioration of soil physical and chemical properties. This paper summarizes the role of interaction between rhizosphere exudates and soil microorganisms in the formation of continuous cropping obstacles, aiming to provide a new research idea for revealing the formation mechanism as well as the theoretical support for overcoming continuous cropping obstacles of medicinal plants.

Effects of chloropicrin fumigation on soil and growth and development of Panax notoginseng / 中国中药杂志

The continuous cropping obstacle of Panax notoginseng is serious, and effective control measures are lacking. Soil disinfection with chloropicrin(CP) has been proven to be effective in reducing the obstacles to continuous cropping of other crops. In order to ascertain the effect of CP in the continuous cropping of P. notoginseng, this paper explored the influences of CP at different treatment concentrations(0,30,40,50 kg/Mu, 1 Mu≈667 m~2) on soil macro-element nutrients, soil enzyme activity, growth and development of P. notoginseng, and the accumulation of medicinal components. The results showed that CP fumigation significantly increased the content of total nitrogen, alkali-hydrolyzable nitrogen, ammonium nitrogen, nitrate nitrogen, and available phosphorus in the soil, but it had no significant effect on potassium content. The soil protease activity showed a trend of first increasing and then decreasing with the prolonging of the treatment time. Both the soil urease and acid phosphatase activities showed a trend of first decreasing and then increasing with the prolonging of the treatment time. The higher the CP treatment concentration was, the lower the urease and acid phosphatase activities would be in the soil. The protease activity was relatively high after CP40 treatment, which was better than CP30 and CP50 treatments in promoting the nitrogen-phosphorus-potassium accumulation in P. notoginseng. The seedling survival rates after CP0, CP30, CP40, and CP50 tratments in October were 0, 65.56%, 89.44%, and 83.33%, respectively. Compared with the CP30 and CP50 treatments, CP40 treatment significantly facilitated the growth and development of P. notoginseng, the increase in fresh and dry weights, and the accumulation of root saponins. In summary, CP40 treatment accelerates the increase in soil nitrogen and phosphorus nutrients and their accumulation in P. notoginseng, elevates the seedling survival rate of P. notoginseng, enhances the growth and development of P. notoginseng, and promotes the accumulation of medicinal components. CP40 treatment is therefore recommended in production.

Correlation analysis between continuous cropping obstacle of Gastrodia elata and Ilyonectria fungi and relieving strategy / 中国中药杂志

The continuous cropping obstacle of Gastrodia elata is outstanding, but its mechanism is still unclear. In this study, microbial changes in soils after G. elata planting were investigated to explore the mechanism correlated with continuous cropping obstacle. The changes of species and abundance of fungi and bacteria in soils planted with G. elata after 1, 2, and 3 years were compared. The pathogenic fungi that might cause continuous cropping diseases of G. elata were isolated. Finally, the prevention and control measures of soil-borne fungal diseases of G. elata were investigated with the rotation planting pattern of "G. elata-Phallus impudicus". The results showed that G. elata planting resulted in the decrease in bacterial and fungal community stability and the increase in harmful fungus species and abundance in soils. This change was most obvious in the second year after G. elata planting, and the soil microbial community structure could not return to the normal level even if it was left idle for another two years. After G. elata planting in soils, the most significant change was observed in Ilyonectria cyclaminicola. The richness of the Ilyonectria fungus in soils was significantly positively correlated with the incidence of G. elata diseases. When I. cyclaminicola was inoculated in the sterile soil, the rot rate of G. elata was also significantly increased. After planting one crop of G. elata and one to three crops of P. impudicus, the fungus community structure in soils gradually recovered, and the abundance of I. cyclaminicola decreased year by year. Furthermore, the disease rate of G. elata decreased. The results showed that the cultivation of G. elata made the Ilyonectria fungi the dominant flora in soils, and I. cyclaminicola served as the main pathogen of continuous cropping diseases of G. elata, which could be reduced by rotation planting with P. impudicus.

Influences of Natural Fibrous Root Decay on Growth and Active Component Content of Paris polyphylla var. yunnanensis / 中国实验方剂学杂志

Objective:To explore the effect of natural decay of exogenously added fibrous roots on the growth and development of <italic>Paris polyphylla</italic> var. <italic>yunnanensis </italic>and its medicinal quality. Method:The effects of natural decay of fibrous roots at different amounts on mycorrhizal infection rate， physiological and biochemical indexes， and saponin contents of <italic>P. polyphylla</italic> var. <italic>yunnanensis </italic>were studied in pot culture experiments at room temperature. Result:The results showed that the infection rate of arbuscular mycorrhizal （AM） fungi in the root of <italic>P. polyphylla</italic> var. <italic>yunnanensis </italic>was not significantly affected by different fibrous root treatments， but there were significant differences in infection intensity. The photosynthetic pigment content in the leaves declined significantly with the increase in fibrous root amount， and the total chlorophyll was decreased by 78.7% at most. The contents of soluble protein， soluble sugar and malondialdehyde in the leaves of <italic>P. polyphylla</italic> var. <italic>yunnanensis </italic>showed an overall upward trend. The activities of the three protective enzymes varied. The peroxidase and malondialdehyde were reduced by 181.6% and 200.0% at most. In the root system of <italic>P. polyphylla </italic>var. <italic>yunnanensis</italic>， the contents of the above-mentioned six components decreased to varying degrees， with the largest reductions of peroxidase and malondialdehyde reaching 44.6% and 69.7%. Different fibrous root treatments resulted in a decrease in active component content of <italic>P. polyphylla </italic>var. <italic>yunnanensis</italic>. The total content of the four saponins was decreased by 58.9% at most， and the total saponin content by 46.9%. Conclusion:The natural decay of fibrous roots affects the soil microbial environment of root system， reduces the photosynthetic pigment content in leaves， and destroys the stability of cells， thus interfering with the growth and development of <italic>P. polyphylla </italic>var. <italic>yunnanensis</italic>， reducing its medicinal components， and causing continuous cropping obstacles.

Research progress on application of biochar in cultivation of agriculture and Chinese materia medica / 中国中药杂志

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.

Production and quality control of original herbal materials of Danhong Injection / 中国中药杂志

Cardiovascular and cerebrovascular diseases are the leading cause of death for residents in China. Danhong Injection(DHI) decoction piece is prepared from Salviae Miltiorrhizae Radix et Rhizoma and Carthami Flos, with the function of promoting the blood circulation, removing the blood stasis, relaxing the sinews and dredging the collaterals. In recent years, about 100 million bottles of DHI have been sold. Consequently, its safety and effectiveness are very important to a large number of patients. Raw materials are the source and foundation for production of traditional Chinese medicine injections. In this article, we reviewed the identification of Salviae Miltiorrhizae Radix et Rhizoma and Carthami Flos, resource distribution, cultivation, quality control, and detection of xenobiotic pollutants, in order to guide the production of high-quality, stable, and pollution-free raw materials. This will be a benefit in ensuring the safety and effectiveness of DHI and reducing the incidence of adverse reactions from the raw materials. By comparing the similarities and differences between the quality standards of Salviae Miltiorrhizae Radix et Rhizoma, Carthami Flos and DHI, we provided some comments for improving the quality standards and post-marketing reevaluation of DHI, and provided some theoretical supports for the production of high-quality herbal raw materials.

Effect of Living Garlic and Isolated Garlic Sprout on Stress of Continuous Cropping Angelica sinensis / 中国实验方剂学杂志

Objective:To explore the allelopathic effect of garlic volatiles on Angelica sinensis by studying the allelopathic effect of both living garlicand isolated garlic sprout volatiles on A. sinensis, and provide certain theoretical basis for Angelica garlic interplanting mode to alleviate the stress of continuous cropping A. sinensis. Method:Through the determination and analysis of the growth indexes and leaf protective enzyme system of A. sinensis，the adaptability of A. sinensis to continuous cropping stress and non-continuous cropping stress environment under the influence of the volatiles of living garlic and isolated garlic sprout as well as the mechanism of resistant growth and development were discussed. Result:The overall analysis showed that the growth index and leaf protective enzyme activity of isolated garlic sprout with alleloinductive treatment（DC2）under continuous cropping stress were increased by 17.51% and 48.34% respectively as compared with those under single cropping（CK1）. The growth index and leaf protective enzyme activity of angelica under continuous cropping and intercropping（LC2）were increased by 16.63% and 36.65% as compared with those under monocrop cropping（CK2）. Those indicated that the volatiles of isolated garlic sprout had more significant effect than those of live garlic on alleviating the stress of continuous cropping of A. sinensis. Conclusion:Regardless of the presence of continuous cropping obstacle，appropriate concentrations of living garlic and isolated garlic sprout volatiles had an allelopathic promoting effect on angelica root growth index and leaf protective enzyme activity，and the effect was more obvious in continuous cropping stress conditions，so intercropping garlic has a certain role in alleviating angelica's continuous cropping stress.

Analysis of Rhizosphere Soil Fungal Community Composition and Diversity of Salvia miltiorrhiza Based on ITS Sequences / 中国实验方剂学杂志

Objective: To study rhizosphere soil fungal community composition and diversity of Salvia miltiorrhiza,in order to explain the changes of the rhizosphere microenvironment of S.miltiorrhiza,and provide theoretical basis for revealing the reasons for the formation of continuous obstacles.Method: Based on the high-throughput sequencing technology,three kinds of soil samples were collected,namely soil of non-plant (CK),soil for cultivating for one year (Y1) and soil for cultivating for two years (Y2),respectively.According to the sequencing of the internal transcribed space of nuclear ribosomal DNA (ITS) region of fungal rRNA gene,14 153,19 024 and 7 622 valid sequences were obtained and annotated as 1 027,1 095 and 712 varieties of OTUs.The diversity of fungal communities showed a trend of decreasing first and then increasing.Agaricomycetes,Leotiomycetes and Tremellomycetes were the dominant bacterial communities at the class level,their orders in three treatments were Y1 > CK > Y2,Y2 > Y1 > CK,CK > Y2 > Y1.At the genus level,Guehomyces was dominant species in CK,and both Y1 and Y2 had a decrease of 96.13% and 90.21%,respectively.Wickerhamomyces had a significantly increase in Y2(6.64%),250.59% and 564.00% compared with CK and Y1,respectively.Result: The results of cluster analysis showed that CK and Y1 had a higher similarity at the genus level in soil fungal community composition compared with Y2.Conclusion: Cryptosporiopsis and other pathogenic fungal communities were dominant genuses according to the heatmap analysis in Y2,suggesting a correlation with the incidence of S.miltiorrhiza.The findings provide theoretical basis for the formation of continuous cropping obstacle.

Advances in molecular identification and functional genes of Rehmannia glutinosa / 中草药

Rehmannia glutinosa is one of the most common bulk medicinal materials in China and it has a long history of medicinal use. In recent years, with the development of molecular biology, especially for the emergence of high-throughput sequencing technology, it not only provides new ways to identify R. glutinosa quickly, and reveal the genetic diversity and relationship of R. glutinosa, but also lays the vital foundation for explaining the mechanism on metabolism, root tuber growth, stress response and continuous cropping obstacles of R. glutinosa. The present paper reviews the recent study progress in molecular biology research of R. glutinosa from molecular systematics, molecular identification and functional genes, and puts forward three research prospects in order to provide a reference for further study on molecular biology of R. glutinosa.

Arbuscular mycorrhizal fungal communities in the rhizosphere of a continuous cropping soybean system at the seedling stage

Abstract Arbuscular mycorrhizae (AM) fungi play a crucial role in the growth of soybean; however, the planting system employed is thought to have an effect on AM fungal communities in the rhizosphere. This study was performed to explore the influence of continuous soybean cropping on the diversity of Arbuscular mycorrhizal (AM) fungi, and to identify the dominant AM fungus during the seedling stage. Three soybean cultivars were planted under two and three years continuous cropping, respectively. The diversity of AM fungi in the rhizosphere soil at the seedling stage was subsequently analyzed using polymerase chain reaction (PCR)-denaturing gradient gel electrophoresis (DGGE). The results showed that an increase in cropping years improved the colonization rate of AM in all three soybean cultivars. Moreover, the dominant species were found to be Funneliformis mosseae and Glomus species. The results of cluster analysis further confirmed that the number of years of continuous cropping significantly affected the composition of rhizospheric AM fungal communities in different soybean cultivars.

Advances in research on allelopathic autotoxicity effects of medicinal plants / 中草药

Allelopathic autotoxicity is one of the important factors for the continuous cropping obstacle of medicinal plants, which will reduce the yield and quality. With the development of medicinal plants industry, the problem of continuous cropping obstacle is becoming more and more serious. How to alleviate the continuous cropping obstacle of medicinal plants needs to be solved urgently. This paper combines the research status of allelopathic autotoxicity in medicinal plants. On the one hand, expounds the mechanism that the allelochemicals of medicinal plants inhibit the growth and development of medicinal plants by damaging the cell structures, interfering with the metabolism of reactive oxygen species and phytohormones, affecting photosynthesis and so on. On the other hand, based on the analysis of the relationship between allelochemicals and continuous cropping obstacle of medicinal plants, this paper elucidated some methods to alleviate the continuous cropping obstacle of medicinal plants, such as breeding antiallelopathic autotoxicity medicinal plants varieties, rational fertilizing, selecting proper cropping system and using microbial agents, in order to provide reference for the production of medicinal plants.

Relationship between occurrence of root-rot and changes of bacterial community structure in rhizosphere soil of Panax quinquefolius / 中草药

Objective In this paper, the changes of bacterial community structure in the rhizosphere soil of healthy and root-rot Panax quinquefolius were investigated to explore the occurrence mechanism of root-rot in P. quinquefolius. Methods The changes of bacterial communities structure in uncultivated soil (group C), rhizosphere soil of 4-year-old healthy ginseng (group N), and 4-year-old root-rot ginseng (group R) were analyzed by using the Illumina MiSeq high-throughput sequencing technology. Results A total of 636 654 effective sequences and 8 422 OTUs were obtained from nine samples based on high-throughput sequencing of the 16S gene. Bacterial species detected in these samples covered 42 phyla, 106 classes, 180 orders, 158 families, and 246 genera. The main phylums were the same in the three groups, including Proteobacteria, Actinobacteria, Acidobacteria, and Chloroflexi with significantly different relative abundance. At the genera level, the composition and relative abundance of the bacterial communities in the three groups are very different. Among them, Rhodoplanes, kaistobacter, and Sphingobium may be the key bacteria causing root rot of P. quinquefolius and should be focused in the further research. Conclusion There are significant differences in the bacterial community composition from the rhizosphere soil of healthy and root-rot P. quinquefolius. This finding plays a theoretical guiding role in exploring the micro-ecological mechanism of root-rot of P. quinquefolius and improving the soil microbial community during the cultivation of P. quinquefolius.

Identification and analysis of the calcium signaling system genes responding to continuous cropping injury in Rehmannia glutinosa L / 药学学报

Calcium signaling plays a critical role in response to various abiotic and biotic stresses in plants. Preliminarily evidence showed that calcium signaling perceived and transduced the harmful signaling generated from continuous cropping stress in R. glutinosa. To investigate the roles of calcium signaling in continuous cropping injury formation, the key genes involved in calcium signaling transduction were identified in R. glutinosa transcriptome through bioinformatic methods. Furthermore, the calcium ion concentration in both normal and continuous cropping R. glutinosa root cells were measured by potassium pyroantimonate precipitation and calcium fluorescence method. As a result, a set of 84 calcium signaling-related genes, including 5 CaMs, 12 CBLs, 21 CDPKs, 21 CIPKs, 16 CMLs, and 9 CRKs were captured in R. glutinosa transcriptome. The analysis of expression profile in continuous cropping compared to normal growth R. glutinosa indicated that continuous cropping stress significantly increased the expression of calcium signaling-related genes in continuous cropping R. glutinosa. At the same time, the abundance levels of 12 calcium signaling-related genes quantified by qPCR further validated the high expression of calcium signaling-related genes presented in continous cropping R. glutinosa. In addition, the continuous cropping condition significantly promoted the accumulation of intracellular calcium ions in R. glutinosa based on two methods of potassium pyroantimonate precipitation and calcium fluorescence. This study verified the possible roles of calcium signaling in the formation of continuous cropping injury on molecular and cellular level, which lays a solid foundation for illuminating formation mechanism of continuous cropping injury on molecular level.

Quantitative Determination of Ferulic Acid Content in Chrysanthemum Morifolium cv. ( Chuju) Continuous Cropping Soil Using Near Infrared Spectroscopy / 分析化学

A near infrared spectroscopy ( NIRS) method was used for rapid quality evaluation of ferulic acid content in chrysanthemum morifolium cv. ( Chuju) continuous cropping soil. Standard leverage, studentized residual and Mahalanobis distance were calculated to eliminate abnormal samples. After the initial near infrared spectrum was treated by two second derivative and Norris smoothing filter noise, 6000-4000 cm-1 wave number range and 7 factors were chosen for partial least squares ( PLS) calibration model. The results showed that good correlation was presented between the calibration set/validation set and the values determined by high performance liquid chromatography, and the calibration correlation coefficient ( Rc ) and validation correlation coefficient ( Rcv ) were 0. 9914 and 0. 9935, respectively. Root mean square error of calibration (RMSEC), root mean square error of validation (RMSEP) and root mean square error of cross-validation (RMSECV) were 0. 484, 0. 539 and 0. 615, respectively. This method was accurate, reliable, simple, rapid and nondestructive, and could be applied to the fast analysis for ferulic acid in continuous cropping soil.

Research progress in microorganism changes of rhizospheric soil and root endogenous and ecology during continuous cropping of Panax notoginseng / 中草药

Panax notoginseng is one of the most important traditional Chinese medicinal herbs, and it is mainly distributed in Yunnan and Guangxi Provinces and only can be planted in a very narrow geographical environment. Its yield is significantly limited by continuous cropping obstacles in the cultivation process, which has seriously affected the application and development of P. notoginseng. The dynamic patterns of root and soil rhizosphere microbial community response were main reasons for the continuous cropping obstacle. In this paper, the dynamic changes of the root and rhizosphere systems, pathogenic microorganisms and symbiotic microorganisms in the formation of P. notoginseng continuous cropping obstacles were analyzed, and the progress in this field was summarized. Two methods for studying soil and root microorganism of continuous cropping process are proposed: 1. The dynamic analysis of microorganism in the rhizosphere and root of P. notoginseng must be completed with the method of pure-culture and culture-independent; 2. Quantitative analysis of main pathogenic microorganisms of P. notoginseng. It will provide theoretical basis for overcoming continuous cropping obstacles in plant of P. notoginseng.

Research progress of relationship between continuous cropping obstacles and microRNAs in Rehmannia glutinosa / 中国中药杂志

The efficacy of Rehmannia glutinosa which as a large quantity of traditional Chinese medicine is significant. However, the land must be given up after one season of R. glutinosa cultivation or replanted after a period of 8-10 years because of the severe continuous cropping obstacles. MicroRNAs is a class of endogenous non-coding small RNAs, which participate in regulation of physiological activities by target mRNA cleavage or translational repression in plants. In recent years,studies on the role of miRNAs in plants have made significant progresses,especially in medicinal plants．MiRNAs from some different medicinal plant species have been identified with regulatory effects．When plants are exposed to environmental stress, miRNAs act on stress-related genes and initiate stress-resistance mechanisms in the body against adverse factors. R. glutinosa is also a kind of environmental stress. It is conducive to deciphering the molecular mechanism of continuous cropping obstacles for us by researching miRNAs. This article reviews the production of miRNAs, mechanism, research approaches and characteristics of resisting the environmental stresses in plants, the development trends and future prospect of R. glutinosa miRNAs research.

DNA marker-assisted selection of medicinal plants (Ⅰ) .Breeding research of disease-resistant cultivars of Panax notoginseng / 中国中药杂志

DNA marker-assisted selection of medicinal plants is based on the DNA polymorphism, selects the DNA sequences related to the phenotypes such as high yields, superior quality, stress-resistance and so on according to the technologies of molecular hybridization, polymerase chain reaction and high-throughput sequencing, and assists the breeding of new cultivars. This study bred the first disease-resistant cultivar of notoginseng "Miaoxiang Kangqi 1" using the technology of DNA marker-assisted selection of medicinal plants and systematic breeding. The disease-resistant cultivar of notoginseng contained 12 special SNPs based on the analysis of Restriction-site Associated DNA Sequencing (RAD-Seq). Among the SNP (record_519688) was related to the root rot-resistant characteristics, which indicated this SNP could serve as genetic markers of disease-resistant cultivars and assist the systematic breeding. Compared to the conventional cultivated cultivars, the incidence rate of root-rot and rust-rot in notoginseng seedlings decreased by 83.6% and 71.8%, respectively. The incidence rate of root-rot respectively declined by 43.6% and 62.9% in notoginseng cultivation for 2 and 3 years compared with those of the conventional cultivated cultivars. Additionally, the potential disease-resistant groups were screened based on the relative SNP, and this model enlarged the target groups and advanced the breeding efficiency. DNA marker-assisted selection of medicinal plants accelerated the breeding and promotion of new cultivars, and guaranteed the healthy development of Chinese medicinal materials industry.

Changes of diversity and composition of fungal communities in rhizosphere of Panax ginseng / 中国中药杂志

Continuous cropping obstacles resulted in the yield losses of Panax ginseng, and affected the development of ginseng industry. Soil fungal communities participated in the key ecological process, and their changes of diversity and composition were related to the continuous cropping obstacles. We analyzed the changes of fungal diversity and composition in the rhizosphere of ginseng using the high-throughput sequencing method, stated the effects of ginseng cultivation on the micro-ecology, and provided effective strategies for overcoming continuous cropping obstacles. Compared to those of the forest soils, the fungal diversity of ginseng rhizosphere soils was increased, and the increasing trends were declined with an increasing years of ginseng cultivation; the relative abundance of Sordariomycetes, Alatospora, Eurotiomycetes, Leotiomycetes, Saccharomycetes, Mucorales and Pezizomycetes were increased in the rhizosphere of ginseng. Pearson's correlation index indicated that soil chemical perporties affected the relative abundance of fungal communities. pH was significantly related to the relative abundance of Dothideomycetes and Alatospora; the content of available potassium was markedly associated with the relative abundance of Dothideomycetes, Alatospora and Mucorales; the content of total nitrogen was significant correlation with the relative abundance of Sordariomycetes and Mucorales. These results indicated that fertilization was one of pivotal factors affecting the rhizosphere micro-ecology of ginseng, and optimization of fertilization system was an effective method to overcome continuous cropping obstacles.

Effect of isolated garlic sprouts on germination properties of Angelica sinensis seeds under simulated continuous cropping stress / 中草药

Objective: To study the effect of volatile from isolated garlic sprouts on the germination characteristics of Angelica sinensis seeds under simulated continuous cropping stress. Methods: Treating the obstacle of A. sinensis seeds under simulate continuous cropping stress with the extract from Angelica Sinensis Radix and using isolated garlic sprouts to simulate garlic volatile allelopathy environment, so as to study the germination characteristics of A. sinensis seeds. Results: The extracts from Angelica Sinensis Radix inhibited the germination of A. sinensis seeds, and the higher the concentration was, the stronger the inhibition effects will be. The volatile from the isolated garlic sprouts promoted the germination of A. sinensis seeds, which was not treated with the extracts from Angelica Sinensis Radix at low concentration (50 g isolated garlic sprouts) and inhibited the germination at high concentration (100-200 g isolated garlic sprouts). The isolated garlic sprouts volatile had certain promoting allelopathy on the germination properties of A. sinensis seeds which were treated with the extracts from Angelica Sinensis Radix. When the fresh weight of the donor garlic sprouts was 50-100 g, the promoting effects on A. sinensis seeds germination reached extremely significant level (P<0.01). When the fresh weight of garlic sprouts was 200 g, the promoting effects were not significant (P<0.05). Conclusion: The volatile from the isolated garlic sprouts could alleviate the germination inhibition by extracts from Angelica Sinensis Radix.