Genetic Variation in Rhizome Lotus(Nelumbo nucifera Gaertn.ssp.nucifera) Germplasms from China Assessed by RAPD Markers

To estimate genetic variation in rhizome lotus （Nelumbo nucifera Gaertn. ssp. nucifera） germplasms in China, a total of 94 rhizome lotus germplasms collected from 18 provinces in China were assessed. The RAPD （randomly amplified polymorphic DNA） marker was employed. The selected 17 random primers detected 139 polymorphic alleles out of a total 207 （67.15%）. Nei＇s gene diversity statistics and region differentiation parameters indicated that all germplasms had a relatively high level of genetic diversity with ne = 1.3202, h = 0.1937, I= 0.2982 and the gene flow among all regions was Nrn = 5.5742. The UPGMA dendrogram clustered all 94 germplasms into two clusters： One contained eight commercial cultivars and major landraces, and the other included the wild and some special landraces from five regions, and the PCA analysis exhibited the similar result. Those germplasms from southwestern and eastern China had higher genetic diversity than those from the southern, northern and central China. Predominant proportion of genetic variation （95.61%） was found significant within rather than among （4.39%） regions, as revealed by AMOVA analysis. The data analysis also revealed that the genetic diversity of rhizome lotus germplasms among different regions is positively related to their geographic distances, though it is ambiguous to find the trend from the UPGMA dendrogram and the PCA analysis. A relatively high genetic diversity and gene flow resided in the root lotus germplasms; about 96% of the variation was found within region; accessions from southwest and eastern China have higher genetic diversity than those from the southern, northern and central China.

Genetic Diversity of Lotus(Nelumbo nucifera Gaertn.) Cultivars Revealed by ISSR Analysis

[ Objectives ] This study was conducted to investigate the genetic diversity of 20 lotus （Nelumbo nucifera Gaertn） samples. [ Methods ] On this optimal ISSR amplification system, 16 primers were screened with good polymorphism, and the DNA was used to amplify the 20 plant samples. [ R^ults] The 16 primers produced 225 loci, of which 170 were polymorphic, and the polymorphic loci percentage was up to 75.56%. The genetic similarity coefficients between the 20 vari- eties ranged from 0. 577 8 to 0.951 1, which were calculated by POPGENE32. The 20 varieties by UPMGA analysis could be clustered into 2 groups, the first of which included Baiyangdian red lotus and Donggua lotus, and other varieties was included in the second group. [ Conchmions] ISSR molecular markers could be effectively used in genetic diversity and fingerprint analysis for different lotus varieties.

Genetic diversity of the wild Asian lotus (Nelumbo nucifera) from Northern China

Asian lotus(Nelumbo nucifera Gaertn.)is an aquatic plant with ornamental,cultural,economic,and ecological values.China has abundant germplasm resources of Asian lotus.However,in many areas,the wild Asian lotuses have been destroyed and the germplasms is now facing extinction.In addition,the knowledge of the genetic diversity of the wild Asian lotus in China is poor.To identify and protect the germplasms of Chinese wild Asian lotus,eleven genomic-SSR primers,three EST-SSR primers,and three chloroplast DNA primers were used to investigate the genetic diversity among 69 samples of wild Asian lotus from 25 locations in northern China.The genetic diversity of 27 samples of wild Asian lotus from southern China and other countries,the ancient Asian lotus,Asian lotus cultivars from China,and Asian-American hybrids was also compared.The genetic diversity of the wild Asian lotus from northern China was characterized as medium,and themean values of observed heterozygosity(Ho)and expected heterozygosity(He)were 0.087 and 0.552,respectively.Based on a UPGMA dendrogram and STRUCTURE analysis,the wild Asian lotus samples in northern China were divided into three groups.The wild Asian lotus samples from northern China contained 16 haplotypes.The Nei’s genetic distance between the wild Asian lotus samples from the Songhua River basin and the Liao River basin in northeastern China was relatively small,and these germplasms might be relatively primitive compared to those from other regions.This study provides essential information regarding the genetic diversity of the wild Asian lotus resources in northern China,and provides a basis for further analysis of population-level genetic evolution through high-throughput sequencing.

Analysis of Accumulating Ability of Heavy Metals in Lotus (Nelumbo nucifera) Improved by Ion Implantation

Heavy metals have seriously contaminated soil and water, and done harm to public health. Academician WANG Naiyan proposed that ion-implantation technique should be exploited for environmental bioremediation by mutating and breeding plants or microbes. By implanting N^＋ into Taikonglian No.l, we have selected and bred two lotus cultivars, Jingguang No.1 and Jingguang No.2. The present study aims at analyzing the feasibility that irradiation can be used for remediation of soil and water from heavy metals. Compared with parent Taikonglian No.l, the uptaking and accumulating ability of heavy metals in two mutated cultivars was obviously improved. So ion implantation technique can indeed be used in bioremediation of heavy metals in soil and water, but it is hard to select and breed a cultivar which can remedy the soil and water from all the heavy metals.

Optimization of slow-release fertilizer application improves lotus rhizome quality by affecting the physicochemical properties of starch

To achieve the dual goals of high yield and good quality with low environmental costs,slow-release fertilizer(SRF)has been widely used in lotus cultivation as new type of fertilizer instead of traditional nitrogen fertilizer.However,the optimal amount of SRF and how it would promote lotus rhizome quality remain unclear.This study was designed to investigate the photosynthetic characteristics and the synthesis,accumulation,and physicochemical properties of lotus rhizome starches under six SRF levels(CK,S1,S2,S3,S4,and S5).Compared with CK(0 kg ha^(–1)),the net photosynthetic rate(P_(n))and SPAD values of leaves remained at higher levels under SRF treatment.Further research showed that SRF increased the lotus rhizome yield,the contents of amylose,amylopectin,and total starch,and the number of starch granules.Among the six SRF levels,S3(1035 kg ha^(–1))showed the greatest difference from CK and produced the highest levels.With the increasing SRF levels,the peak,hot and final viscosities decreased at first and then increased,but the setback viscosity and pasting temperature increased.In order to interpret these changes at the molecular level,the activities of key enzymes and relative expression levels of starch accumulation related genes were analyzed.Each of these parameters also increased under SRF treatment,especially under the S3 treatment.The results of this study show that SRF,especially S3(1035 kg ha^(–1)),is a suitable fertilizer option for lotus planting which can improve lotus rhizome quality by affecting starch accumulations related enzymes and genes.These results will be useful for SRF application to high-quality lotus rhizome production with low environmental costs.

Effect of Specific Structure of Lotus Seed Oligosaccharides on the Production of Short-chain Fatty Acids by Bifidobacterium adolescentis

In order to study the structure of lotus （Nelumbo nucifera Gaertn） seed oligosaccharides and their effect on the proliferation ofBifidobacterium adolescentis, we extracted the oligosaccharides from seeds collected from Jianning County, China. We preliminarily characterized the groups, molecular weights, molecular formulae, component monosaccharides and glycosidic bonds using mass spectrometry （MS） and nuclear magnetic resonance （NMR） after isolation and purification. The lotus seed oligosaccharides contained glycosidic bonds Manp-（1→）, Galp-（1→）, α（1→6）-Glup and α（1→6）-Manp; and mannose was the chief component monosaccharide. NMR analyses showed that ~t-glycosidic bonds and pyranoid rings were predominant in the oligosaccharides. The MS analyses showed that lotus seed oligosaccharides consisted of three oligosaccharides of different polymerization degree, with relative molecular weights of 342, 504 and 666 Da, and corresponding molecular formulae C12H22O11, C18H32O16 and C24H42O21. Research on the effect of lotus seed oligosaccharides on the proliferation orB. adolescentis showed that they effectively promoted the production of acetic, propionic and butyric acids by B. adolescentis through fermentation, and their effect was stronger than that of fructo-, xylo- and isomalto-oligosaccharides. Lotus seed oligosaccharides have potential as a new functional probiotic and lotus seeds should be further explored and utilized as a source of oligosaccharides.

Whole genome re-sequencing reveals evolutionary patterns of sacred lotus (Nelumbo nucifera)

Sacred lotus(Nelumbo nucifera or lotus) is an important aquatic plant in horticulture and ecosystems. As a foundation for exploring genomic variation and evolution among different germplasms, we re-sequenced 19 individuals from three cultivated temperate lotus subgroups(rhizome,seed and flower lotus), one wild temperate lotus subgroup(wild lotus), one tropical lotus group(Thai lotus) and an outgroup(Nelumbo lutea). Through genetic diversity and polymorphism analysis by non-missing SNP sites widely distributed in the whole genome, we confirmed that wild and Thai lotus exhibited greater differentiation with a higher genomic diversity compared to cultivated lotus. Rhizome lotus had the lowest genomic diversity and a closer relationship to wild lotus, whereas the genomes of seed and flower lotus were admixed. Genes in energy metabolism process and plant immunity evolved rapidly in lotus, reflecting local adaptation.We established that candidate genes in genomic regions with significant differentiation associated with temperate and tropical lotus divergence always exhibited highly divergent expression pattern. Together, this study comprehensive and credible interpretates important patterns of genetic diversity and relationships, gene evolution, and genomic signature from ecotypic differentiation of sacred lotus.

湘莲根际促生菌的筛选及其效应研究

为获得湘莲根际促生菌(Plantgrowth promoting rhizobacteria,PGPR)并明确其促生特性,试验从湘莲根际土壤中分离出7株固氮解磷菌,通过对其功能指标的对比挑选出菌株XL7,其具有良好的固氮解磷和产IAA能力。经鉴定该菌株为高地芽孢杆菌(Bacillus altitudinis)。通过种子萌发、盆栽试验测定菌株对湘莲的促生效应。结果表明:接种XL7能促进种子的萌发,发芽势、发芽率、苗长、苗重和不定根重均高于对照;土壤中矿质态氮、速效磷和速效钾分别提高了5.3%、31.8%和26.1%;莲幼苗植株生物量、全氮、全磷和全钾分别增加了25.0%、18.3%、80.5%和38.7%。这表明该多功能菌株对湘莲具有良好的促生作用。

山东莲藕(Nelumbo nucifera Gaertn.)种质资源的RAPD鉴定和遗传多样性分析

山东莲藕(Nelumbo nucifera Gaertn.)栽培历史悠久,在中国北方具有重要影响。但是,山东莲藕种质资源研究一直没有开展。为收集和保存莲藕种质资源,本研究从山东省8个种植面积较大的地区采集了76份莲藕材料,并利用RAPD分子标记对这些材料进行了遗传相似性分析,共鉴定出38份种质资源。遗传多样性指数分析显示,38份种质资源的Nei's多样性指数(H)平均值为0.26,Shannon信息指数(I)平均值为0.41。研究数据表明,山东莲藕种质资源相对丰富,但要建立高质量的种质资源圃,仍需要加强种质资源的引进。

莲藕多糖的碱法提取工艺优化与抗氧化活性评价

目的 优化莲藕多糖的碱法提取工艺并评价其抗氧化活性。方法 以多糖提取率为指标,以料液比、NaOH浓度、提取时间和提取温度为考察因素进行单因素实验,结合响应面法对提取工艺进行优化,并分析所得莲藕多糖的纯度、相对分子质量和自由基清除能力。结果 响应面优化结果显示,除料液比以外,NaOH浓度、提取时间和提取温度对莲藕多糖提取率均具有显著影响(P<0.05)。确定最佳工艺条件为:料液比1:16(g/mL)、NaOH浓度0.04 mol/L、提取时间1.3 h、提取温度57℃,此条件下的多糖提取率达13.07%,与预测值13.52%相近。该碱法提取多糖的纯度达73.66%,平均相对分子质量为1.727×10^(5)Da。抗氧化活性评价结果显示,莲藕多糖具有清除1,1-二苯基-2-三硝基苯自由基和羟基自由基的能力,且清除率与多糖浓度成正比。结论 优化了碱提莲藕多糖的提取工艺,且提取得到的多糖具有较好的抗氧化活性,为莲藕资源的开发利用提供了理论依据。

不同观赏荷花品种对镉胁迫响应的差异性研究

[目的]本文旨在探讨不同观赏荷花品种耐镉(Cd)的差异,筛选优质荷花品种以作为植物修复Cd污染水体的材料。[方法]以常用的6个大中型观赏荷花品种为试材,利用盆栽试验研究不同Cd处理水平(0、1、10、25 mg·kg-1)下各荷花品种生长及生理特性的变化。[结果]低Cd处理(1 mg·kg-1)促进了各荷花品种株高和立叶数的增加,中Cd处理(10 mg·kg-1)对‘风卷红旗’‘中国红·北京’‘珠峰翠影’的株高和立叶数有促进作用,但抑制其他3个品种的生长,经高Cd处理(25 mg·kg-1)后仅‘珠峰翠影’的株高和立叶数仍显著增加;不同Cd处理水平对各荷花品种冠幅和叶径的生长均产生了抑制效果。随着Cd处理水平升高,各荷花品种叶片的叶绿素含量逐渐降低,相对电导率不断上升,超氧化物歧化酶(SOD)和过氧化物酶(POD)活性均呈先上升后下降的趋势。其中,‘风卷红旗’‘中国红·北京’和‘珠峰翠影’叶绿素含量及相对电导率受Cd胁迫的影响较其他3个品种小,且‘风卷红旗’和‘中国红·北京’的2种抗氧化酶活性仅在高Cd胁迫下才显著低于对照,而‘珠峰翠影’在各水平Cd处理下始终高于对照。对不同荷花品种Cd积累特性的分析表明,‘风卷红旗’和‘中国红·北京’的Cd积累量相对较高,而‘珠峰翠影’的Cd转运系数最高;荷花不同器官中Cd积累量由大到小表现为根、叶、根状茎。[结论]不同观赏荷花品种耐Cd能力差异较大,‘珠峰翠影’‘风卷红旗’‘中国红·北京’的耐Cd性相对较强,这3个耐性品种可通过根系阻挡与固定大量Cd或高效启动抗氧化系统清除Cd诱导产生过量活性氧的方式抵御Cd胁迫。

荷叶中的生物碱及其对5-HT 2A和5-HT 2C受体的激动作用研究

对荷叶中的生物碱进行了分离、鉴定和调脂减肥活性研究。本研究结合传统酸提碱沉法与现代高效液相色谱制备技术,从荷叶中分离、纯化到11个生物碱,分别被鉴定为N-氧基原荷叶碱(1)、原荷叶碱(2)、莲碱(3)、降氧化北美黄连次碱(4)、荜茇宁(5)、巴婆碱(6)、O-去甲基荷叶碱(7)、N-去甲基荷叶碱(8)、荷叶碱(9)、衡州乌药碱(10)和亚美罂粟碱(11),其中,化合物1、4和5为首次从荷叶中分得。测试所得化合物对5-HT_(2A)和5-HT_(2C)受体的激动作用,结果表明11个生物碱对5-HT_(2A)受体均具有一定的激动作用,进一步揭示了荷叶调脂减肥的可能药效基础和作用机理。

莲藕膨大过程中碳水化合物变化的初步研究

在莲藕膨大过程中,测定其干物质、淀粉、可溶性总糖、还原糖、可溶性蛋白质等含量,研究碳水化合物的变化规律。结果表明:干物质、淀粉和可溶性蛋白质含量在莲藕膨大过程中均逐渐上升,至膨大后期有一个急增过程;还原糖含量先有所上升,膨大中期迅速下降,至膨大后期维持较稳定水平;可溶性总糖含量从膨大始期至膨大中期平缓上升,至膨大后期则迅速增加。莲藕根状茎的储藏物质主要为淀粉。

钾素营养对莲藕生长和干物质累积的影响

采用大盆试验研究了钾素营养对莲藕生长和干物质累积的影响,结果表明,钾素营养明显增加莲藕立叶数量和立叶面积、提高立叶相对叶绿素值和组织器官含水量、延缓叶片衰老、增强立叶抗逆性,从而促进莲藕生育前期光合产物的累积和健康生长;钾素营养还适当延长莲藕成熟期,促进干物质从叶片转移并贮存到产品中,使莲藕增产20.4%。

不同干燥方式对莲藕脆片品质的影响

为明确休闲莲藕脆片的最佳干燥方式,采用热风干燥、真空微波干燥、热风-真空微波干燥、热风-气流膨化干燥、真空微波-气流膨化干燥、热风-真空微波-气流膨化干燥6种不同的干燥方式对莲藕片进行干燥后,对所得脆片的色泽、收缩率、硬度、脆度、VC保留率、多酚保留率以及微观结构等品质指标进行分析。结果表明:热风干燥对莲藕脆片色泽影响不大,但硬度过低,脆度差,VC和多酚损失最为严重;真空微波干燥莲藕脆片VC和多酚保留率高,脆性好,但硬度过高,产品皱缩严重,色差和褐变度高;4种不同联合干燥方式生产的莲藕脆片品质较单一干燥的产品均有所改善,其中,热风-真空微波-气流膨化干燥的莲藕片收缩程度和褐变程度较真空微波干燥显著降低,而VC和多酚保留率较热风干燥显著升高,硬度、脆度均适中,多孔性好。综上所述,热风-真空微波-气流膨化干燥是最适宜加工莲藕休闲脆片的方法。

莲藕部分种质资源数量性状的聚类分析与育种应用

对 17个不同地区、不同类型的莲藕资源进行了系统聚类分析 ,将莲藕分为野生资源类、地方品种资源类和改良品种类三大类群。品质性状野生资源最优 ,地方品种和改良品种相当 ;农艺性状改良品种最优 ,地方品种居中 。

湖北省莲藕品种演变及栽培利用特点

湖北省是莲藕起源地之一,亦为我国莲藕重要产区。其品种演变历史可划分为传统品种阶段(1980年以前)、新品种选育的起步和奠基阶段(1980～1990年)、传统品种更新和新品种快速推广与持续选育时期(1990年以后)。不仅拥有许多传统品种,而且选育了多个新品种,是我国莲藕新品种的主要选育地区。在莲藕茬口配置、设施栽培、种藕繁殖、采挖以及莲藕产品开发利用等方面具有明显的地方特色。

莲子心脂溶性生物碱的分离、鉴定

为进一步分离并鉴定保健食品莲子心中活性脂溶性生物碱,根据脂溶性成分和酚性生物碱的化学性质,先将莲子心脂溶性成分提取、分离酚性和非酚性二个部位;再运用多种柱色谱技术分别对这二个提取部位进行分离纯化,并对所得化合物的理化性质和光谱数据(UV,IR,MS,~1H NMR、^(13)C NMR及其2D-NMR)进行分析归纳,最终确定它们的化学结构。从莲子心脂溶性部位共获得12个单体化合物,经鉴定其中10个成分为生物碱。酚性部位有6个化合物,分别为:l-薄荷醇(l-menthol,1),甲基莲心碱(neferine,2),亚美罂粟碱(amepavine,3),4'-甲氧基-N-甲基衡州(4'-methoxy-N-methyl coclaurine,4),异莲心碱(isoliensinine,5),莲心碱(liensinine,6);非酚性部位有6个化合物,分别为:谷甾醇(sitosterol,7),荷叶碱(nuciferine,8),前荷叶碱(pronuciferine,9),莲明碱(lysicamine,10),N-甲氧基头花千金藤二酮B(N-methoxycepharadione B,11)和N-甲基紫堇定(N-methylcordaldine,12)。其中1、4、10、11和12则为该植物中首次发现的化合物。

离子对反相HPLC法测定10个产地莲子心中莲心碱的含量

目的 建立用离子对反相 HPL C法测定莲子心药材中莲心碱含量的方法。方法 选用 ODS色谱柱 ,流动相为甲醇 -水 -冰醋酸 -辛烷磺酸钠 -乙酸钠 (5 5∶ 45∶ 0 .6∶ 10 m mol/ L∶ 5 m mol/ L ) ,检测波长 2 82 nm ,流速为1.0 m L/ min,柱温为 40℃。结果 莲心碱在 0 .0 0 5～ 0 .146 m g/ m L范围内 ,线性关系良好 (r=0 .9999) ;平均回收率为 10 0 .6 % ,RSD为 1.2 1% (n=6 )。结论 该法准确 ,快速 ,灵敏 ,重现性好 。

乳状液膜分离提取荷叶中3种生物碱

建立了用W/O型乳状液膜分离提取荷叶中3种生物碱——N-去甲基荷叶碱、O-去甲基荷叶碱和荷叶碱的方法。通过对迁移时间、表面活性剂Span 80用量、载体D2EHPA浓度、油内比、乳水比和内水相盐酸浓度的优化,获得了高效的液膜体系,为:迁移时间2.5 min,表面活性剂Span 80的质量分数为3.0%,载体D2EHPA的浓度为0.01 mol/L,油内比为10∶6,乳水比为10∶60,内水相盐酸浓度为0.2 mol/L。在优化的实验条件下,对荷叶中3种生物碱N-去甲基荷叶碱、O-去甲基荷叶碱和荷叶碱的萃取率分别达到了95.6%、100%和97.9%,相应的富集因子依次为8.73、8.50和8.04。说明该乳状液膜体系能够很好地分离提取荷叶中的N-去甲基荷叶碱、O-去甲基荷叶碱和荷叶碱。