Effect of Purple Yam(Dioscorea alata L.) on Nutritional and Physiological Functions of Growing Rats

[Objective] This study was to explore the effect of purple yam on the nutritional and physiological functions of rats.[Method] Forty SD rats were randomly divided into four groups with ten rats in each group which were reared with artificial semisynthetic feed added with 10% steamed yam powder.The four groups,the casein（CK） group which was used as the control,the purple yam（PY） group,the Tiegun yam（TY） group and common Huai yam（HY） group,were supplied with feed of equal content of energy,protein and fat.The rats were pair-fed for 56 days to observe changes of relevant nutritional and physiological indices.[Result] There were no significant differences of body weight,food conversion rate and organ indices between rats in PY group and CK group.Mean corpuscular hemoglobin in PY group was significantly lower than that in CK group;hemoglobin showed no significant difference with that in CK group;eosnophils was lower than that in CK group.Low density lipoprotein-cholesterol,total cholesterol and atherogenic index in PY group were lower than that in the other three groups;anti-atherogenic index was the highest among the four groups,while showing no significant difference;triglyceride content was lower than that in CK group.Among the antioxidant indices,the activity of catalase and superoxide dismutase were higher than that in CK group,while malondialdehyde content was lower than that in CK group.[Conclusion] Purple yam showed the trend of reducing the content of blood glucose,total cholesterol,low density lipoprotein-cholesterol,triglyceride,malondialdehyde,and raising the activity of glutathione peroxidase,superoxide dismutase and catalase,thus having certain antioxidative function.

叶喷水杨酸对山药(Dioscorea alata L.)地下块茎蔗糖—淀粉转化影响(英文)

【目的】阐明叶喷水杨酸(SA)对山药地下块茎蔗糖—淀粉转化的影响,为了解山药蔗糖转化机制、提高其淀粉形成提供参考。【方法】设置SA 0.0(对照)、0.5、1.0和5.0 mmol/L 4个处理,在山药(Dioscorea alata L.)"白扁"地下块茎形成的早期和后期分别进行叶面喷施,定期采样测定地下块茎主要碳水化合物含量和蔗糖裂解与淀粉形成的相关酶活性。【结果】除5.0 mmol/L SA处理的后期地下块茎总可溶性糖(TSS)含量急剧增加外,地下块茎的TSS、蔗糖、葡萄糖、果糖、淀粉、直链淀粉(AM)、支链淀粉(AP)和纤维素的含量在其他处理间的变化趋势相同。与对照相比,0.5mmol/L与5.0 mmol/L SA处理对山药地下块茎的影响作用相反,前者不仅显著提高了蔗糖合成酶(SuSase)、酸性转化酶(SAInv)、细胞壁结合酸性转化酶(CWBAInv)、中性转化酶(NInv)等酶的活性,而且显著增加腺苷二磷酸焦磷酸化酶(AGPase)、可溶性淀粉合成酶(SSS)、颗粒结合淀粉合成酶(GBSS)、淀粉分支酶(SBE)等酶的活性,1.0 mmol/L仅在块茎发育中期对上述酶有微小的促进作用。所有SA处理中,虽然蔗糖含量与SuSase及淀粉合成相关酶的活性呈不显著正相关,但蔗糖与总可溶性糖含量的比率与这些酶活性及淀粉含量成显著正相关。葡萄糖、果糖含量及它们所占总可溶性糖的比率与上述酶的活性分别呈显著负相关,葡萄糖与果糖的比率与上述酶的活性无显著相关性,蔗糖与葡萄糖、果糖的比率均与AGPase、SSS、GBSS的活性呈显著正相关。【结论】叶面喷施SA在山药地下块茎发育过程中通过作用于蔗糖裂解和淀粉合成相关酶的活性来影响蔗糖的运输和流向,小于1.0 mmol/L的SA通过提高酶活性来促进蔗糖转运入山药地下块茎并转化成淀粉,而其他浓度SA具有相反的作用。

Effect of Synthetic Hormone Substitutes on Rooting of Vine Cuttings in Water Yam (Dioscorea alata L.)

The use of yam vine cuttings as propagules with appropriate synthetic rooting hormones such as IBA (Indole-Butyric Acid) and NAA (Naphthalene Acetic Acid) has previously been reported as successful but expensive. To source for cheaper alternatives, this study compared the effect of some natural and synthetic hormones on rooting of vine cuttings in two varieties of Dioscorea alata. Vine cuttings from three months old water yam varieties were treated separately with 1%, 3% and 5% concentrations of each of the following: neem leaf ash, coconut water, 2,4-D and IBA with water as control. Treated cuttings were planted in triplicates in polythene bags using the completely randomised design and watered once in two days for 49 days. Data collected on rooting percentage, number of roots per plant, mean root length, number and length of new vines were subjected to analysis of variance tests and the means separated using least significant difference tests. A 100% rooting was observed in vines treated with 1% or 3% coconut water and neem ash. These vines also generated significantly greater number of new vines (P < 0.05) compared to those from synthetic hormones. Vines treated with 5% neem produced the highest number of roots (145.33 ± 9.21;P < 0.001) while those treated with 3% neem produced the longest roots (45.3 ± 9.23 cm) followed by those treated with 3% coconut water (24.3 ± 3.48). The study reveals that neem leaf ash and coconut water are better root promoting agents for water yam vines than 2,4-D and IBA and could be tested further for use as natural hormonal substitutes to the synthetic hormones.

Analysis of Tuber Yield- and Maturity- Related Traits in Water Yam （Dioscorea alata L.）

Inadequate yield potential of available varieties and their long growth periods are two of the factors limiting yam （Dioscorea spp.） production. Identifying yield- and maturity-related traits and breeding for them will enhance production. Ten morphological/physiological traits： time of shoot emergence, time of tuber initiation, plant height, shoot dry weight, time of shoot senescence, tuber fresh weight （tuber yield）, tuber number/plant, tuber parenchyma colour, tuber dry matter content and tuber dormancy period were assessed in eight accessions of D. alata L. （water yam） on the field in 2008 and 2009. Tuber yield-related traits were identified as shoot dry weight and time of shoot emergence. Shoot dry weight had the strongest positive effect; time of shoot emergence had a negative effect. High yielding accessions had a high shoot dry weight, but were low in tuber dry matter content. Uniform tuber parenchyma colour was the sole trait related to tuber maturity, but early and late senescing accessions did not consistently differ in the trait. TDa 00/00103 is high yielding and early maturing and may be used as a parent for breeding for high yield and early maturity in D. alata.

Acetone Extract of <i>Dioscorea alata</i>Inhibits Cell Proliferation in Cancer Cells

Dioscorea spp., White Yam has been shown to exhibit a wide range of nutritional and medicinal properties. However, the compounds associated with its medicinal functions have not been fully examined. The purpose of this study was to generate a chemoinformatic profile of the bioactive compounds present in Dioscorea. alata (D. alata) and to characterize their putative anti-cancer properties using prostate (DU145) and lung (A549) cancer cells. Chemoinformatic profiling of D. alata resulted in five bioactive extracts: hexane (DaJa-1), ether (DaJa-2), acetone (DaJa-3), ethanol (DaJa-4) and water (DaJa-5) were generated. The analytes present in the five bioactive extracts were dissolved in 0.1% DMSO and their anti-cancer activity were determined. We observed that the acetone extract (DaJa3) was the only extract capable of inducing greater than 90% cell death of DU 145 cell at 100 μg/mL. The order of growth inhibition of the extracts in DU-145 cell is DaJa-3 (IC50, 31.45 μg/mL) > DaJa-4 (IC50 60 μg/mL) > DaJa-1 (IC50 > 100 μg/mL) ≥ DaJa-2 (IC50 > 100 μg/mL) ≥ DaJa-5 (IC50 > 100 μg/mL). MTT cell viability, dye exclusion, caspase activity and microscopic assessment of apoptotic cells demonstrated that DaJa-3 displayed cytotoxicity to both lung and prostate cancer cells. The A549 cells were more sensitive toward DaJa-3 with an IC50 value of 22.28 μg/mL (CI 28.42 to 36.63 μg/mL), compared to that of DU145 cells with an IC50 value of 31.45 μg/mL (CI 27.58 to 35.86 μg/mL). It was also observed that DaJa-3 induces differential anti-proliferative activity in the cancer cells. The apoptotic response induced by DaJa-3 paralleled the level of cell cytotoxicity observed in both cell lines. DaJa-3 induces G2 phase cell cycle arrest in DU145 cells but G1 arrest in A549 cells. The level of key apoptotic regulator proteins was upregulated, suggested that DaJa-3 may be mediating its anti-cancer effect through activation of the intrinsic apoptotic pathway. Altogether, our data indicates that DaJa-3 derived from a staple food source (white Yam) contains unique active compounds that have specific biological properties that may prevent certain types of cancer or specific types of cancer.

Application of Prochloraz-nano-titanium Dioxide Complex Fresh-keeping Agent in Refrigeration of Dioscorea alata Lirm. sp.

Prochloraz diluents( 450 ×,475 ×,500 ×) were added with different concentrations of nano-titanium dioxide( Ti O2)( 0. 8%,1. 0%) respectively to prepare complex fresh-keeping agents,which were applied in the refrigeration of Dioscorea alata Lirm. sp. With rot index,weight loss rate,browning degree( BD),total soluble solids( TSS) content,malondialdehyde( MDA) content,polyphenol oxidase( PPO) activity and peroxidase( POD) activity,DPPH· scavenging rate as evaluation indexes,the preservation effect of the prepared freshkeeping agents on D. alata during the cold storage period was analyzed. The results showed that prochloraz added with nano-titanium dioxide significantly prolonged the storage life,reduced the rot rate and weight loss rate,and slowed the loss of pulp of D. alata. The preservation effect of complex fresh-keeping agent of prochloraz diluent( 475 ×) and nano-titanium dioxide( 1. 0%) was better than that of other treatments.

山药块茎生长膨大相关基因的筛选与分析

为筛选山药块茎生长膨大相关基因,采用生物信息学方法,对山药块茎发育前期和中期构建的不同发育阶段抑制性消减杂交(suppression subtractive hybridization,SSH)文库进行分析。结果表明:山药块茎发育前期与中期差异表达基因(differential expression genes,DEGs)序列主要涉及九大类,其中发育调控占比最大(27.1%),其他依次为细胞组织结构(14.0%)、物质代谢(11.2%)、生物合成(4.7%)等。初步筛选出泛素-连接酶体(F-box associated,F-box)、碳酸酐酶(carbonic anhydrase,CAs)、核苷二磷酸激酶(nucleoside diphosphate kinase,NDPK)、氨基酸透性酶(amino acid permease)、糖基转移酶(glycosyl transferase)、α-淀粉酶(α-amylase,AMY)等候选基因,它们可能与细胞增殖、细胞伸长、激素代谢、酸碱环境调节及功能物质代谢物等功能有关,参与调控山药块茎的生长膨大。

山药颗粒结合型淀粉合成酶基因DaGBSS的克隆与分析

颗粒结合型淀粉合成酶(granule-bound starch synthase,GBSS)是一种能够决定直链淀粉生物合成的关键性酶。通过对山药转录组分析、分子克隆获得一个具有完整ORF的DaGBSS基因,cDNA片段长度为1845 bp,编码614个氨基酸。生物信息学分析结果显示DaGBSS蛋白为一酸性稳定蛋白,含有淀粉合酶催化和糖基转移酶2个功能结构域。多序列比对结果显示:糯米山药DaGBSS蛋白与所选的物种具有较高的同源性,且含有典型的功能结构域;生物进化分析结果显示DaGBSS蛋白与圆形薯蓣亚种进化亲缘关系最近。对采收15 d山药块茎进行处理,qRT-PCR、指标分析结果显示DaGBSS基因在山药块茎的表达存在明显的时空差异性,且在距离地表位置最远的部位DaGBSS基因的表达量、GBSS和直链淀粉的含量均为最高。研究通过对山药块茎淀粉合成的早期阶段进行生理、关键调控因子的克隆分析,为探究山药淀粉合成的调控提供参考,同时对糯米山药的分子育种提供了重要的基因资源。

不同肉色脚板薯营养成分和功能成分分析

以紫色、白色2种肉色脚板薯为试材,采用高效液相色谱法、电感耦合等离子体发射光谱法(ICP-OES)和pH示差法对其氨基酸、单糖、尿囊素、薯蓣皂苷、微量元素及总花色苷含量进行检测分析,并测定水分、蛋白质、淀粉等成分含量。结果表明:2种不同肉色脚板薯营养成分和功能成分存在一定差异性。白色肉脚板薯蛋白质含量显著高于紫色肉,而水分和淀粉含量显著低于紫色肉;微量元素Bi、Rb和Se含量为白色>紫色,Mo、Ca、Mg元素为白色<紫色,其他元素差异不明显;必需和非必需氨基酸总含量为白色>紫色;富含精氨酸,含量为白色>紫色,分别为297.96和97.08 mg/kg;富含尿囊素,含量为白色>紫色,分别为30.03和24.53 mg/kg;单糖、薯蓣皂苷、总花色苷含量均为白色<紫色,单糖组成为葡萄糖>半乳糖>甘露糖>半乳糖醛酸>木糖>核糖>阿拉伯糖>葡萄糖醛酸>鼠李糖>岩藻糖。

山药PAL基因全长cDNA序列的克隆、表达与分析

为了阐明苯丙氨酸解氨酶（PAL,EC4.3.1.5）基因在山药地下块茎酚类物质积累过程中的分子机理,本研究运用普通PCR、RACE和TAIL-PCR技术从大薯（Dioscorea alataL.）’Zixiao’地下块茎中克隆到同一个PAL基因的3个片段,即长度分别为1 145bp、1 151bp和424bp的中间片段、3’端和5’端的cDNA序列;将3段cDNA序列拼接后获得大小为2 376bp的PAL基因全长cDNA序列,该序列含有一个1986bp的最大开放阅读框（ORF）,一个28bp的5’端非翻译区,一个362bp含25 nt的Poly（A＋）尾的3’端非翻译区,最大ORF可推测编码一个包括PAL酶活性中心的特征序列（GTITASGDLVPLSYIA）在内的661个氨基酸的多肽,分子量为71.974kDa,等电点6.310;大薯地下块茎的PAL基因分别在核苷酸与氨基酸水平上和GenBank中所选已知其他物种的同源性为73%~77%和76%~82%,说明PAL基因在系统进化上相对保守;RT-PCR分析表明该基因仅在地下块茎中表达,而且表达丰度在收获前逐渐降低。

脚板薯淀粉的理化性质研究

从脚板薯淀粉颗粒的形态大小、淀粉中直链淀粉与支链淀粉的比例、淀粉的粘度和糊化温度等方面研究了脚板薯淀粉的理化性质,从而得到一系列脚板薯淀粉性质的参数:脚板薯淀粉颗粒纵径范围42.67～79.69μm,平均值为61.66μm,横径范围为33.43～44.58μm,平均横径为39.22μm,其直链淀粉含量为总淀粉的27.18%.其初始糊化温度为65～67°C.

山药及其同属植物参薯中多糖含量的测定

采用硫酸 苯酚显色,分光光度法测定了山药及其同属植物参薯中的多糖含量.结果显示,不同产地山药多糖含量差别不大,而山药和参薯的多糖含量差别较大.

紫参薯的包埋玻璃化超低温保存

以紫参薯带芽茎段为材料,采用2%海藻酸钠和0.1mol/L氯化钙凝胶系统制备包埋珠,液氮保存,以茎段细胞活力和包埋珠成活率为指标筛选获得有关参数适宜水平,比较冻后再生苗与常温苗形态及生理指标.结果表明:紫参薯试管苗经4℃锻炼6d后,无菌条件下制备其带芽茎段包埋珠,接种到MS+2 mg/L KT+0.2 mg/L NAA+0.5mol/L蔗糖液体培养基中预培养1d,转入MS+2 mol/L甘油+0.4 mol/L蔗糖溶液中室温下装载40min,在玻璃化保护剂PVS2中脱水40min,更新PVS2后迅即液氮保存,24h后置于37℃水浴中化冻5min,用MS+2mg/L KT+0.2mg/L NAA+0.8mol/L蔗糖溶液洗涤3次(每次10min),然后转入MS+2mg/L KT+0.2mg/L NAA+30g/L蔗糖+1g/L活性炭固体培养基中,暗培养7d后转至光照下培养14d,该包埋珠成活率可达60%.冻后再生苗诸多形态和生理指标与常温苗差异不具有统计学意义.

反相高效液相色谱法测定紫山药中薯蓣皂苷的含量

建立薯蓣属中紫山药中薯蓣皂苷含量测定方法,考察不同产地紫山药中薯蓣皂苷的含量,并与该属中其他山药进行对比。样品经冷冻干燥后研磨成粉末,然后经70%甲醇回流提取1h,采用HPLC法进行测定。色谱柱:DiamonsilTM(钻石)C18柱(250mm×4.6mm,5μm),流动相:甲醇-水(84∶16),流速:1.0mL·min-1,检测波长:206nm,柱温:30℃。结果表明,薯蓣皂苷与其他成分分离良好,线性范围0.65～65μg·mL-1(r=0.9999),回收率100.6%,不同产地山药中薯蓣皂苷含量差异较大。该方法简便、准确、重现性好,可用于山药及其同属其他植物中薯蓣皂苷的质量控制。

粤东地区三种薯蓣植物营养品质比较

淮山(Dioscorea opposita Thunb.)、姜薯(Dioscorea alata L.)、参薯(Dioscorea alata L.var.purpurea(Roxb.)M.Pouch)同为薯蓣科植物中常见的药食两用植物,在粤东地区有广泛的种植与应用。为了比较这3种薯蓣在营养品质上的差异,本研究采用国家标准食品检测法对它们食用部位的多个理化性质进行测定,包括水分、还原糖、淀粉、可溶性总糖、粗脂肪、粗蛋白质、VC、多酚类物质、黄酮类物质以及多酚氧化酶活性等10个指标。结果表明3种薯蓣主要由糖类物质、蛋白质以及少量脂肪构成,干物质中淀粉占很高比例。三者的营养品质存在一定的差异。从干物质方面来看,淮山>姜薯>参薯,其中,淮山含有的淀粉、可溶性总糖、粗脂肪的含量比另外两种高;在粗蛋白含量方面,姜薯>参薯>淮山。同时本文还检测了多酚类物质、黄酮类物质、VC等的含量以及多酚氧化酶的酶活力,参薯的均高于其他两种。从总体上看,这3种薯蓣均具备良好的营养价值,其中姜薯部分营养价值以及抗氧化活性等药用价值方面均优于淮山和参薯。这表明姜薯是一种具有良好开发前景的植物资源。

大薯微型块茎的离体诱导

研究IBA、BA、蔗糖、光照以及昼夜温差对大薯(Dioscorea alata L.)微型块茎诱导形成的影响,确定影响大薯微型块茎形成的重要因素,筛选最佳培养方案。以大薯组织培养不定芽为材料,研究不同植物激素浓度、蔗糖含量、光照时间和昼夜温差对大薯微型块茎形成时间、形成率、平均微块茎数和直径的影响。添加植物激素能促进大薯微型块茎提早成形,IBA和BA对大薯微型块茎的形成表现为增效作用;蔗糖浓度对大薯微型块茎的成形具有显著作用,在不添加蔗糖的培养基中,没有成形的大薯微型块茎,适当增加蔗糖浓度能提高大薯微型块茎的形成率,而高浓度的蔗糖则会抑制大薯微型块茎的形成和生长。以IBA2.0mg/L+BA0.5mg/L,蔗糖浓度为60g/L时,所诱导的微型块茎较多且大,为诱导大薯微型块茎的最佳培养基组合。短光照和昼夜温差处理也能显著提高微型块茎的诱导率,数量和大小。植物激素、蔗糖浓度、光照和昼夜温差均为影响大薯微型块茎形成的重要因素。IBA和BA配合作用时表现互作效应,而其互作作用也受蔗糖浓度和光温条件的影响。是否添加蔗糖直接决定有无大薯微型块茎的形成。

台州紫山药组织培养快繁技术研究

以浙江省台州紫山药带腋芽的茎段为外植体进行紫山药种苗的快速繁殖。结果表明：70％乙醇浸泡30 s及84消毒液消毒15～20 min配合使用灭菌效果最好；腋芽诱导最适培养基为MS＋0.5 mg·L-16-BA＋0.1 mg·L-1 NAA，培养25 d后诱导的芽数最多，平均芽数为1.58，高度最高，为2.3 cm；生根培养最适培养基为1/2 MS＋0.1 mg·L-16-BA＋2.0 mg·L-1 NAA＋0.02％活性炭，平均生根天数为6 d，生根率达100％，气生根率低，根系长而粗壮；生根培养基中培养30 d后，将试管苗按节切段繁殖，繁殖系数可达3.0。

111份大薯种质资源遗传多样性AFLP分析

采用AFLP分子标记方法对收集于6省不同地区的111份大薯种质资源进行遗传多样性分析。筛选到的8个AFLP引物组合扩增到1291个位点，其中1286个是多态性位点。利用多态性信息含量（PIC）、标记指数（MI）和解析强度（RP）分析不同引物组合的标记效率，获得引物的 PIC平均值为 0.22，MI平均值为35.67，RP平均值为50.50，表明引物扩增位点的高多态性和对大薯种质资源具有强辨别能力，其中引物E-AAC/CAG-M（PIC 0.24、MI 38.56、 RP 56.32）具有较高的标记效率。111份大薯种质的遗传相似系数（GS）在0.30～0.82之间，平均为0.58，表明大薯种质资源的遗传相似性较低。采用UPGMA对大薯种质进行聚类分析，遗传相似系数在0.54时，111份材料被划分为4个类群和3个单独的分支（序号分别为20、42、47），不同地区来源的大薯材料在聚类图中没有明显界限。

湿法消解-原子吸收光谱法测定紫山药中矿质元素

以福建省武平县和云南省红河州紫山药块根为实验材料,采用湿法消解-原子吸收光谱法对其中12种矿质元素含量进行分析检测。结果表明：湿法消解-原子吸收光谱法能准确测定紫山药中矿质元素的含量,回收率在92.00%~106.00%之间,相对标准偏差在10%以下,且方法简单、快捷;供试的紫山药中矿质元素含量丰富,不仅富含Mg、Fe、Zn,还含有对人体有益的Se元素。重金属中除了Ni元素,其他重金属（Cr、Pb、As、Cd、Hg）的含量均符合GB 2762—2012《食品中污染物限量》。

紫山药对生长中大鼠营养生理功能的影响

[目的]观察紫山药(Dioscorea alata L.)对大鼠营养生理功能的影响。[方法]生长期SD大鼠40只随机分为4组,每组10只,饲喂添加了10%山药熟粉的人工半合成饲料,以酪蛋白组作为对照组,3个试验组分别为紫山药组、铁棍山药组和普通怀山药组。各组饲料的能量、蛋白质、脂肪含量均保持一致。采用对喂法喂养60 d,观察有关营养生理指标的变化。[结果]紫山药组大鼠体重、食物转化率及脏器指数均与对照组无显著差异。平均血红蛋白显著低于对照组,但血红蛋白含量与对照组无差异;嗜酸性粒细胞低于对照组。紫山药组大鼠低密度脂蛋白(LDL)、总胆固醇(TC)和致动脉硬化指数(AI)低于其他3个组,而抗动脉硬化指数(AAI)最高,但无显著差异。甘油三酯(TG)低于对照组。抗氧化指标中,紫山药组大鼠血清中过氧化氢酶(CAT)、超氧化物歧化酶(SOD)活性都高于对照组,丙二醛(MDA)含量低于对照组。肝组织中,紫山药组大鼠总抗氧化能力、CAT、谷胱甘肽过氧化物酶(GSH-Px)、SOD活性都高于对照组,而MDA含量低于对照组。[结论]紫山药具有降低大鼠血糖、胆固醇、低密度脂蛋白、甘油三酯、MDA含量,提高GSH-Px、SOD、CAT活性的趋势,具有一定的抗氧化作用。