Preliminary Identification of Red Pigment and Positive Correlation between the Contents of Red Pigment and Total Saponins of Panax notoginseng Fruits

[Objective] This study aimed to identify red pigment of Panax notoginseng fruits and explore the correlation between pigment content and total saponins of the fruits. [Method] The red pigment of Panax notoginseng fruits was preliminarily identi- fied with specific color reactions and UV-vis spectra, and the contents of the pigment and total saponins were determined via spectrophotometry. [Result] The red hues of the fruits were contributed by anthocyanins and/or the anthocyanidins. The contents of anthocyanins and total saponins of the fruits both decreased along with thinning of the red hues. The content difference of the anthocyanins in fruits with different red hues reached extremely significant level, but that of total saponins just reached significant level. [Conclusion] The red pigment of P. notoginseng fruits is anthocyanins which are of extremely significant positive correlation with total saponins in contents.

Responses of Photosynthetic Pigment, Phenol and Total Saponin Contents of Panax notoginseng to Supplemental UV-B under Field Conditions

[Objective] The aim of this study was to investigate the content changes and their correlations of the photosynthetic pigment,phenols,including total phenols,total flavonoids and anthocyanins,and total saponins of the one-year-old P.notoginseng plants under supplemental UV-B stress in fields.[Method] The one-year-old plants were irradiated by UV-B in field for 1 min per day,and the plants under the UV-B lamp were regarded as a circle center,achieving an annular leaf-sampling.The photosynthetic pigment,phenols and total saponins of the leaves were determined spectrophotometrically.[Result] With the increase of sampling radius,the supplemental UV-B intensity decreased significantly,the contents of chlorophyll （Chl） a,Chl b,Chl （a＋b）,carotenoid （Car） and total photosynthetic pigment （Chl＋Car） of the leaves increased extremely significantly,the Chl a/b and total phenol content （TPC） decreased extremely significantly,but the Chl （a＋b）/Car changes were not significant.The contents of total flavonoids,anthocyanins and saponins all increased due to the increasing of UV-B,displaying dose effects.The UV-B intensity was positively correlated with the Chl a/b,and negatively with the Chl a,Chl b,Chl （a＋ b）,Car and （Chl＋Car） contents; and the two of TPC,total flavonoid content （TFC）,total anthocyanin content （TAC） and total saponin content （TSC） were positively correlated,all reaching extremely significant level.The UV-B intensity was positively and significantly correlated with the total flavonoid content （TFC）,negatively and significantly with the Chl （a＋b）/Car,and positively and insignificantly with the TPC,TAC and TSC.[Conclusion] For one-year-old plants of P.notoginseng,UV-B can decrease the contents of the Chl a,Chl b,Chl （a＋b）,Car and （Chl＋Car） and increase the Chl a/b and TPC,and,furthermore,induce the increases of the TFC,TAC and TSC in a dose-dependent manner.However,UV-B can hardly change the Chl （a＋b）/Car.The supplemental UV-B of well-suited dose might be one of the effective measures to improve the TSC of P.notoginseng.

Effects of total saponins of Panax notoginseng on immature neuroblasts in the adult olfactory bulb following global cerebral ischemia/reperfusion

The main active components extracted from Panax notoginseng are total saponins. They have been shown to inhibit platelet aggregation, increase cerebral blood flow, improve neurological behavior, decrease infarct volume and promote proliferation and differentiation of neural stem cells in the hippocampus and lateral ventricles. However, there is a lack of studies on whether total saponins of Panax notoginsertg have potential benefits on immature neuroblasts in the olfactory bulb following ischemia and reperfusion. This study established a rat model of global cerebral ischemia and reperfusion using four-vessel occlusion. Rats were administered total sa- ponins of Panax notoginseng at 75 mg/kg intraperitoneally 30 minutes after ischemia then once a day, for either 7 or 14 days. Total saponins of Panax notoginseng enhanced the number of dou- blecortin （DCX）＋ neural progenitor ceils and increased co-localization of DCX with neuronal nuclei and phosphorylated cAMP response element-binding/DCX＋ neural progenitor cells in the olfactory bulb at 7 and 14 days post ischemia. These findings indicate that following global brain ischemia/reperfusion, total saponins of Panax notoginseng promote differentiation of DCX＋ cells expressing immature neuroblasts in the olfactory bulb and the underlying mechanism is related to the activation of the signaling pathway of cyclic adenosine monophosphate response element binding protein.

Anti‑inflammatory and Cytotoxic Triterpenes from the Rot Roots of Panax notoginseng

Four new protopanaxatriol-type triterpenes(1-2)and glucosides(3-4),were isolated from the rot roots of Panax notoginseng(Burk.)Chen,along with four known ones(5-8).Their structures were elucidated on the basis of extensive spectroscopic analysis(HRESIMS,NMR,UV,IR,and OR)and acidic hydrolysis.The possible transformation pathway of these compounds were also speculated from ginsenoside Rg_(1).Compound 1,with a uniqueα,β-unsaturated ketene in its side chain,showed significant inhibitory effects against NO production on Murine macrophage cells(IC_(50)=4.12±0.20μM)and comparable cytotoxicities against five human cancer cell lines(myeloid leukemia HL-60,lung cancer A-549 cells,hepatocellular carcinoma SMMC7721,breast cancer MCF-7,and colon cancer SW480)to positive control,cisplatin(DDP).

Advances in Researches of Extraction, Separation, and Purification Technologies for Total Saponins of Panax notoginseng

Total saponins of Panax notoginseng have the functions of promoting blood circulation and removing phlegm, thus they have high medicinal value. There are many different extraction methods in the extraction and separation of total saponins of P. notoginseng . The extraction methods of total saponins of P. notoginseng are mainly divided into traditional extraction methods, modern extraction methods and compound extraction methods.

First Report of Fusarium striatum Causing Root Rot Disease of Panax notoginseng in Yunnan,China

Panax notoginseng is a traditional Chinese medicinal plant.Root rot of P.notoginseng is one of the most serious diseases affecting P.notoginseng growth and causes wilted leaves,fewer lateral roots and rotten roots.Root rot is a soil-borne disease,and mainly occurs from June to August in Yunnan Province when the temperatures are high and the air is humid.In this study,the endophytic fungal genus Fusarium isolate E-2018.1.22-#3.2 was obtained from a P.notoginseng embryo.Fusarium isolate E-2018.1.22-#3.2 was identified as Fusarium striatum based on morphological characteristics and molecular analysis.The fungus was found to have conidiophores and macroconidia,and its ITS,LSU and TEF-1αgenes shared 100%,99.2%and 99%identities with the homologous genes of Fusarium striatum,respectively.Isolate F.striatum E-2018.1.22-#3.2 can cause root rot symptoms,including black,soft roots,fewer lateral roots and leaf wilt,in 93%of the experimental P.notoginseng plants,and could be re-isolated,fulfilling Koch’s postulates.When the P.notoginseng plants were treated with the fungicide pyraclostrobin,isolate F.striatum E-2018.1.22-#3.2 was unable to cause root rot.We have therefore demonstrated that F.striatum E-2018.1.22-#3.2 is able to cause root rot disease in P.notoginseng.This is the first report of root rot disease caused by F.striatum on P.notoginseng in China.

Studies on the Isolation, Identification and In Vitro Growth Rates of the Three Pathogenic Fungi from Panax notoginseng Cultivated in Wenshan Eparchy

Objective] The aim of this study was to simultaneously isolate and identify the main pathogenic fungi of the root rot, black spot and round spot from the Panax notoginseng plants cultivated in Wenshan Eparchy of Yunnan Province of China. [Method] The pathogenic fungi were isolated and purified by using potato dextrose agar （PDA） medium. The morphological identification was accomplished first according to the colony forms of the fungi when cultivated in vitro, then accord-ing to the symptom characteristics and colony forms of the re-isolated fungi in the reverse inoculation experiments. The molecular identification was performed accord-ing to the amplification and alignment of the internal transcribed space （ITS） se-quences of the fungi. The increases of the diameters and thickness of the colonies of the fungi cultivated in vitro were employed to indicate the growth rates of the fungi. [Results] The consistency of the colony forms and symptom characteristics and the 96%-99% similarities revealed in the ITS sequence alignments al proved that the main pathogenic fungi of the root rot, black spot and round spot of the P. notoginseng plants raised in Wenshan were Cylindrocarpon didymium, Alternaria panax and Mycocentrospora acerina, respectively. When cultivated in vitro in the same temperature, humidity and il umination, the increases of the colony diameters and thickness of C. didymium were the highest, fol owed by those of A. panax, then those of M. acerina. During different cultivation periods, the differences of the colony diameters and thickness of the three fungi al reached extremely significant level. However, at the same cultivation time, the differences of the diameters and thickness among the three fungi only reached significant level. [Conclusion] The main pathogenic fungi which result in the root rot, black spot and round spot of the P. notoginseng in Wenshan are C. didymium, A. panax and M. acerina, respec-tively. When these three diseases break out at the same time, the root rot wil spread fastest, fol owed orderly by the black spot and the round spot.

Effects of Organic and Medium and Trace Element Fertilizers on Yield and Quality of Panax notoginseng

[Objectives]This study aimed to investigate the effects of organic and medium and trace element fertilizers(Ca,Zn,B)on yield and quality of Panax notoginseng to provide theoretical support for rational fertilization in cultivation of P.notoginseng.[Methods]Five fertilization treatments,control(CK),organic fertilizer(OM),zinc fertilizer(ZF),boron fertilizer(BF)and lime(LF),were designed.A two-consecutive-year field plot trail was conducted.The biological traits,yield and saponin content of P.notoginseng were determined.[Results]The application of organic fertilizer had no significant effect on the biological traits of P.notoginseng.Trace element fertilizers significantly increased the scape length of P.notoginseng.Among the treatments,ZF significantly increased the single flower weight but reduced the inflorescence diameter,while the effects of BF were opposite to those of ZF;LF significantly increased the stem thickness and reduced the plant height.All treatments significantly increased the seedling rate of three-year-old P.notoginseng,and the increase in the LF group(20.49%)was the largest,followed by those in the ZF(16.80%)and OM(16.40%)groups,and the increase in the BF group(13.08%)was the smallest.Although OM,ZF and BF treatments caused the root weight of individual plants to decrease,the final yield of each treatment was higher than that of the control group,and the increases in the BF and LF groups exceeded 17%(P<0.05).The total saponin outputs of all the treatments except OM were significantly higher than that of the control group.[Conclusions]Under the conditions of this test,the supplementation of organic and medium and trace element fertilizers on the basis of conventional fertilization will help to increase the yield of P.notoginseng.However,the reduction of the total saponin output of P.notoginseng caused by organic fertilizer cannot be ignored.

Advances in Researches of Extraction Processes of Total Saponins of Pnanx Notoginseng

Traditional extraction methods of total saponins of Panax notoginseng include cold soaking method,water decoction method,alcohol reflux method,percolation method,macroporous resin adsorption method,and accelerated solvent extraction( ASE) method. Modern extraction methods include ultrasonic extraction,microwave assisted extraction,supercritical CO_2 extraction,microbial fermentation assisted extraction,neural network model optimized extraction method,and multi-stage countercurrent extraction method. This paper discussed principles of these methods and compared their advantages and disadvantages.

三七(Panax notoginseng)根残体化感自毒效应研究

为研究三七(Panax notoginseng(Burk)F.H.Chen)采收过程中残留须根的化感自毒效应,采用土培和水培2种方法,按不同比例添加三七须根粉碎物,检测根残体作用下土培三七土壤中皂苷的动态变化及水培三七根部形态结构变化。结果显示,土培条件下,随着须根粉碎物处理时间的延长,土壤中皂苷成分种类增加、总皂苷含量减少。水培条件下,随着处理时间的延长,添加须根粉碎物处理后的三七根尖细胞壁增厚,细胞中出现菌丝体;随着处理时间及处理浓度的增加,细胞开始皱缩甚至破碎,细胞中无完整细胞器结构,三七根部细胞结构差异明显。研究表明三七采收过程中残留在土壤中的须根腐解释放的化学物质可能是导致三七自毒效应的因素之一。

Calibration and experimental verification of discrete element parameters of Panax notoginseng root

Existing discrete element method-based simulation analysis of Panax notoginseng root soil separation still has the challenge to get the accurate and reliable basic parameters,which are necessary for discrete element simulation.In this paper,the P.notoginseng roots suitable for harvesting period were taken as the experimental object.Then using 3D scanning reverse modeling technology and EDEM software to establish the discrete element model of P.notoginseng,based on which,the physical and virtual tests were carried out to calibrate the simulation parameters.First,the basic physical parameters(density,triaxial geometric size,moisture content,shear modulus,and elastic modulus)and contact coefficients(static friction coefficient,rolling friction coefficient,and crash recovery coefficient between P.notoginseng roots and 65Mn steel)were measured by physical tests.Furthermore,treating the contact coefficients of P.notoginseng roots as the influence factor,the steepest uphill test,and four factors combing five levels of rotational virtual simulation are conducted.The measured relative error accumulation angle and simulation accumulation angle are set as the performance indices.The results show that the static friction coefficient,rolling friction coefficient,crash recovery coefficient,and surface energy coefficient of P.notoginseng roots are 0.55,0.35,0.16,and 19.5 J/m2,respectively.Using calibration results as parameters of the vibration separation simulation test of P.notoginseng soil,the Box-Behnken vibration separation simulation tests were carried out,in which the vibration frequency,inclination angle,and vibration amplitude of separation device as factors,screening rate and damage rate of P.notoginseng soil complex are regarded as indices.The results show that the optimal operating parameters of the separation device are the vibration frequency of 10 Hz,the inclination angle of 5°,and the amplitude of 6 cm.Based on the optimal operation parameters,the discrete element simulation experiment and field experiment of P.notoginseng roots soil separation are also performed to compare the soil three-dimensional trajectory space coordinates of P.notoginseng roots.From the results,three axis coordinate error is less than 15%.This proves that the calibration results are reliable.It can also provide the theoretical basis and technical support for the further study of the P.notoginseng root soil separation platform.

Combination of Total Astragalus Extract and Total Panax Notoginseng Saponins Strengthened the Protective Effects on Brain Damage through Improving Energy Metabolism and Inhibiting Apoptosis after Cerebral Ischemia-Reperfusion in Mice

Objective： To explore the effects and molecular mechanisms of the combination between total Astragalus extract （TAE） and total Panax notoginseng saponins （TPNS） against cerebral ischemia- reperfusion injury. Methods： C57BL/6 mice were randomly divided into sham-operated group, model group, TAE （110 mg/kg） group, TPNS （115 mg/kg） group, TAE-TPNS combination group and Edaravone （4 mg/kg） group, treated for 4 days, then, cerebral ischemia-repeffusion injury was established by bilateral common carotid artery （CCA） ligation for 20 min followed by reperfusion for 1 and 24 h. Results： TPNS could increase adenosine triphosphate （ATP） level, TAE and TAE-TPNS combination increased ATP, adenosine diphosphate （ADP） contents and Na＋-K＋-ATPase activity, and the effects of TAE-TPNS combination were stronger than those of TAE or TPNS alone after reperfusion for 1 h. After reperfusion for 24 h, TAE, TPNS and TAE-TPNS combination significantly increased neurocyte survival rate and decreased the apoptosis rate as well as down-regulated the expression of phosphorylated c-June N-terminal kinasel/2 （p-JNK1/2）, cytochrome C （Cyt C）, cysteine aspartic acid-specific protease （Caspase）-9 and Caspase-3. Furthermore, the effects in TAE-TPNS combination were better than those in TAE or TPNS alone. Conclusion： The combination of TAE 110 mg/kg and TPNS 115 mg/kg could strengthen protective effects on cerebral ischemia injury, the mechanism underlying might be related to improving jointly the early energy metabolism, and relieving the delayed apoptosis via inhibiting the mitochondrial apoptosis pathway of JNK signal transduction.

Total Saponins of Panax notoginseng Activate Akt/mTOR Pathway and Exhibit Neuroprotection in vitro and in vivo against Ischemic Damage

Objective:To reveal the neuroprotective effect and the underlying mechanisms of a mixture of the main components of Panax notoginseng saponins(TSPN)on cerebral ischemia-reperfusion injury and oxygenglucose deprivation/reoxygenation(OGD/R)of cultured cortical neurons.Methods:The neuroprotective effect of TSPN was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide(MTT)assay,flow cytometry and live/dead cell assays.The morphology of dendrites was detected by immunofluorescence.Middle cerebral artery occlusion(MCAO)was developed in rats as a model of cerebral ischemia-reperfusion.The neuroprotective effect of TSPN was evaluated by neurological scoring,tail suspension test,2,3,5-triphenyltetrazolium chloride(TTC)and Nissl stainings.Western blot analysis,immunohistochemistry and immunofluorescence were used to measure the changes in the Akt/mammalian target of rapamycin(mTOR)signaling pathway.Results:MTT showed that TSPN(50,25 and 12.5μg/m L)protected cortical neurons after OGD/R treatment(P<0.01 or P<0.05).Flow cytometry and live/dead cell assays indicated that 25μg/m L TSPN decreased neuronal apoptosis(P<0.05),and immunofluorescence showed that 25μg/m L TSPN restored the dendritic morphology of damaged neurons(P<0.05).Moreover,12.5μg/m L TSPN downregulated the expression of Beclin-1,Cleaved-caspase 3 and LC3 B-Ⅱ/LC3 B-Ⅰ,and upregulated the levels of phosphorylated(p)-Akt and p-mTOR(P<0.01 or P<0.05).In the MCAO model,50μg/m L TSPN improved defective neurological behavior and reduced infarct volume(P<0.05).Moreover,the expression of Beclin-1 and LC3 B in cerebral ischemic penumbra was downregulated after 50μg/m L TSPN treatment,whereas the p-mTOR level was upregulated(P<0.05 or P<0.01).Conclusions:TSPN promoted neuronal survival and protected dendrite integrity after OGD/R and had a potential therapeutic effect by alleviating neurological deficits and reversing neuronal loss.TSPN promoted p-mTOR and inhibited Beclin-1 to alleviate ischemic damage,which may be the mechanism that underlies the neuroprotective activity of TSPN.

Process performance and quality attributes of temperature and step-down relative humidity controlled hot air drying of Panax notoginseng roots

The effects of temperature and step-down relative humidity controlled hot-air drying(THC-HAD)on the drying kinetics,energy efficiency and quality,i.e.,rehydration ratio(RR),color parameters(L*,a*,b*),total color difference(ΔE*),Panax notoginseng saponins(PNS)content,and ginsenosides content(R1,Rg1,Re,Rd,Rb1)of Panax notoginseng roots were evaluated.The drying time was significantly affected by the drying temperature followed by the relative humidity(RH)of the drying air.Special combination of drying conditions,i.e.,drying temperature of 50°C,relative humidity of 40%for 3 h and then continuous dehumidification from 40%to 8%allowed to shorten the drying time by 25%compared to drying at the same temperature and continuous dehumidification.The longer was the drying time under constant high RH of drying air,the lower was the RR of dried samples.The step-down RH strategy contributed to the formation of a porous structure,enhancement of drying efficiency and quality improvement.Generally,the ginsenosides content increased with the increase in temperature,while no obvious trend was recorded for ginsenoside R1.The contents of the ginsenoside R1,Rg1,Rb1 and PNS decreased with the increase in the drying time under constant high RH.Taking into account the drying time,energy consumption and quality attributes,drying at the temperature of 50°C,constant RH of 40%for 3 h and then step-down RH from 40%to 8%was proposed as the most favorable combination of drying conditions for dehydration of whole Panax notoginseng roots.

Effects of combined infrared and hot-air drying on ginsenosides and drying characteristics of Panax notoginseng(Araliaceae)roots

Exploring new drying technology can help to deal with the challenge of better preservation of rhizome medicinal materials in the traditional Chinese medicine industry.In current work,combined infrared and hot-air drying(IR-HAD)was employed to Panax notoginseng roots and its effect on drying kinetics,energy efficiency and quality,i.e.,rehydration ratio(RR),color parameters(L^(*),a^(*),b^(*)),total color difference(ΔE),Panax notoginseng saponins(PNS)content,and ginsenosides content(R_(1),R^(g1),R_(e),R_(d),R_(b1))were evaluated.Hot air drying(HAD)was used as the control.Results showed that the increase in drying temperature significantly shortened drying time and reduced energy consumption.The shortest drying time of 43.0 h and lowest specific energy consumption of 15.9 kW·h/(kg-water)were obtained by IR-HAD at 55°C.The decrease of radiation distance and the increase of radiation power led to the shortening of drying time.However,high drying temperature resulted in largeΔE values,large collapse structure,and RR of samples.The drying time of Panax notoginseng roots dried by IR-HAD at a drying temperature of 50°C was shorter(15.5%)than HAD dried at the same drying temperature.The contents of R_(1),R_(g1),R_(e),R_(b1),and PNS were higher when the samples were dried by IR-HAD than those dried by HAD at the same temperature of 50°C.Moreover,the IR-HAD dried samples shortened 15.5%drying time and saved 22.1%energy consumption compared with HAD.Therefore,the optimal process condition was Panax notoginseng roots under IR-HAD at drying temperature of 50°C,radiation distance of 12 cm and radiation power of 1350 W,which can shorten drying time,maintain high ginsenosides contents and satisfactory apparent qualities.

三七总皂苷对脑缺血再灌注后神经功能恢复的影响

目的探究三七总皂苷对脑缺血再灌注后神经功能恢复的影响。方法培养30只SPF级雄性SD大鼠,构建脑缺血再灌注模型。将大鼠分为假手术组、模型组和三七总皂苷组,每组10只大鼠。检测各组大鼠脑梗面积、脑含水量。Longa评分评价大鼠神经功能缺损情况。水迷宫实验检测大鼠神经功能。检测各组大鼠血清中氧化应激指标超氧化物歧化酶(superoxide dismutase,SOD)、丙二醛(malondialdehyde,MDA)、谷光甘肽(glutathione,GSH)含量和炎症因子指标肿瘤坏死因子-α(tumor necrosis factor-α,TNF-α)、白细胞介素-1β(interleukin-1β,IL-1β)、白细胞介素-10(interleukin-10,IL-10)含量。Tunel染色检测各组大鼠海马神经元细胞凋亡情况。结果和假手术组大鼠相比,模型组大鼠脑梗面积、脑含水量、神经功能缺损评分、学习潜伏期和记忆潜伏期显著升高,SOD、GSH、IL-10含量显著降低,MDA、TNF-α、IL-1β含量显著升高,海马神经元凋亡比例显著升高(P<0.05)。和模型组大鼠相比,三七总皂苷组大鼠脑梗面积、脑含水量、神经功能缺损评分、学习潜伏期和记忆潜伏期显著降低,SOD、GSH、IL-10含量显著升高,MDA、TNF-α、IL-1β含量显著降低,海马神经元凋亡比例显著降低(P<0.05)。结论三七总皂苷可能通过抑制大鼠炎症反应和氧化应激,减少海马神经元凋亡,促进脑缺血再灌注后神经功能恢复。

健康与罹病三七内生真菌的分离鉴定及其群落特征差异分析

[目的]本文旨在探究健康与罹患根腐病三七内生真菌群落特征差异及在不同植株部位的分布特征与随生长年限的变化规律。[方法]选取1年、2年生健康与罹患根腐病的三七植株,采用组织分离法对其根、茎部位的内生真菌进行分离,基于形态特征和ITS序列分析对分离得到的菌株进行分类鉴定,并对内生真菌群落组成及多样性特征进行分析。[结果]共分离获得966株内生真菌,经鉴定隶属于3门、5纲、14目、25科、31属。从菌株分离数及分离率看:罹病植株>健康植株,2年生>1年生,根部>茎部。健康和罹病三七的可培养内生真菌组成存在明显差异,其中曲霉属、耙齿菌属、毛壳属和青霉属在健康三七内生真菌群落中占主导,而镰刀菌属、曲霉属、篮状菌属、毛壳属和木霉属是罹病三七内生真菌的优势属。植株部位对三七内生真菌群落组成具有明显影响,其中罹病三七根部镰刀菌属的分离频率高达52%,显著高于其茎部的11.2%,且在罹病三七根部大量分离到木霉属和篮状菌属等有益真菌,其分离频率分别为11.0%和14.5%,而三七茎部内生真菌群落多样性、丰富度和均匀度均高于根部。此外,随着生长年限的增加,三七内生真菌群落的发育更加完善,健康和罹病三七内生真菌群落组成及多样性特征也随之变化,其中尖孢镰刀菌和腐皮镰刀菌在罹病三七植株中的分离频率大幅增加,达到14.5%和32.9%。健康三七内生真菌多样性、丰富度和均匀度随生长年限增加逐渐上升,而罹病三七内生真菌多样性和均匀度逐渐降低。[结论]三七植株内生真菌多样性丰富,健康和罹病三七可培养内生真菌定殖数量及群落组成具有显著差异,且植株部位与生长年限均对三七可培养内生真菌群落特征具有显著影响。

品种对三七根系构型的影响及其与品质的关系

【目的】分析不同品种三七的根系形态指标及主根皂苷含量差异,探究根系形态特征与三七生物量及皂苷含量和累积量的关系,为基于三七根系形态特征的高品质三七品种选育提供理论依据。【方法】以苗乡三七1号(M1)、苗乡7号(M7)、苗乡8号(M8)和文院紫七1号(Z1)4个三七品种的2年生植株为研究对象,利用根系扫描仪测定三七的根系形态指标,通过高效液相色谱法测定三七主根中主要皂苷的含量,同时测定三七的地上部和地下部生物量,并分析根系形态指标与三七生物量、根冠比及皂苷含量和累积量的相关性。【结果】不同三七品种的地上部、地下部生物量及根冠比存在一定差异,其中Z1的地上部鲜重最高,M1的地下部鲜重和干重最高,而M8的根冠比最大;不同三七品种的根系形态特征也存在差异,M7、M8和Z1的总根长、总根尖数和分枝数均显著大于M1(P<0.05,下同),M7和Z1的总根表面积显著大于M1;不同三七品种主根中的皂苷含量及累积量,以Z1主根中三七皂苷R1、人参皂苷(Rg_(1)、Rb_(1)和Rd)及总皂苷含量最高,以M1主根中各单体皂苷累积量及总皂苷累积量最高。相关分析结果表明,总根表面积、根平均直径、总根体积等根系形态指标与三七地上部和地下部生物量及皂苷累积量均呈正相关,且粗根(根直径>2mm)根表面积、根体积与三七地上部和地下部生物量及皂苷累积量的相关性大于细根(根直径≤2 mm)。【结论】不同三七品种的根系形态特征、生物量、皂苷含量及累积量存在一定差异,且三七的总根表面积、根平均直径、总根体积等根系形态指标与三七的生物量和皂苷累积量关系密切,良好的根系形态特征对三七生长和品质形成至关重要。

患根结线虫病三七的根际土壤细菌群落特征分析

根结线虫病主要危害三七根部,同时也导致三七病原侵入引起复合侵染从而造成根的坏死与腐烂,影响三七产量。为了解健康三七与患根结线虫病的三七根际土壤中细菌群落多样性。通过收集健康三七根际土壤(HK)、根结线虫病三七根际土壤(GB)和空白对照(CK),并利用16S rRNA基因对细菌群落进行多样性分析,结果显示健康三七皂苷含量(Rg1、Re、Rd)显著高于根结线虫病三七。在群落多样性分析中,健康三七根际细菌群落独有OTU个数为497个显著高于感病三七427个和CK 460个。多样性指数比较中(ace、chao1、Shannon)健康与根结线虫病三七根际细菌群落无显著差异,但均显著高于空白对照(CK),PCoA分析3者细菌群落结构相似性较低(R^(2)=0.544,P=0.008),各处理土壤中优势细菌存在差异,CK中Bradyrhizobium、JG30a-KF-32、Saccharimonadales、Granulicella、WPS-2等菌属显著富集;健康三七中显著富集的是Chujaibacter、Bryobacter、AD3等;根结线虫病三七中Gemmatimonas、Rhodanobacte等显著富集。根结线虫侵染使三七皂苷含量下降,同时LEfSe分析指示健康三七根际中富集更多生防菌如Bryobacter等,这为三七致病菌的生物防治工作提供了新的思路。

三七根腐病菌尖孢镰刀菌实时荧光LAMP检测体系的建立及应用

为了实现对三七根腐病菌的快速准确诊断、及时阻断病菌传播、开展针对性防治,建立了一种现场快速检测三七根腐病菌尖孢镰刀菌的实时荧光LAMP技术。首先从GenBank中筛选出尖孢镰刀菌类跨膜蛋白(TP)基因,并针对其保守区域设计了一套LAMP特异性引物,通过对尖孢镰刀菌LAMP检测体系的反应温度、内引物、外引物、环引物、Mg^(2+)、dNTPs浓度进行优化,并评价体系的特异性及灵敏性,最后应用建立的LAMP检测方法分析三七病株及土壤样品中尖孢镰刀菌的含量。结果表明,LAMP检测方法最佳反应条件为:反应温度64℃,内引物、外引物以及环引物的最佳浓度分别为1.6,0.2,0.1μmol/L,Mg^(2+)浓度6 mmol/L,dNTPs浓度0.4 mmol/L。利用建立的LAMP检测体系能从7种三七根腐病菌中特异性检测出尖孢镰刀菌,且灵敏度高,检测的最低模板浓度为0.2 pg/μL。此外,将DNA简提法和钙黄绿素指示剂与LAMP检测体系结合,建立了一种三七根腐病菌尖孢镰刀菌的现场快速检测方法,可快速准确检测三七植株及种植土壤中的尖孢镰刀菌,为土壤处理、根腐病的早期诊断和动态监测以及三七种子、种苗流通过程中的带菌分子检测提供技术支持。