库拉索芦荟组培中的褐变现象及防止

[目的]研究库拉索芦荟组培中的褐变现象,寻求防止褐变的有效措施。[方法]以库拉索芦荟茎尖、中部茎段和根茎为外植体,以MS为基本培养基,分别附加NAA0.1 mg/L和不同浓度的6-BA(1.0、1.5、2.0、3.0、4.0 mg/L),研究不同外植体类型、激素浓度以及培养温度、活性炭等因素对芦荟组培褐变的影响。[结果]用库拉索芦荟茎尖做外植体,MS+6-BA2.0 mg/L+NAA0.1 mg/L做培养基,芦荟组培褐化程度较轻;培养基中加入活性炭500.0 mg/L,环境温度控制在25℃有利于减轻褐变。[结论]茎尖是最佳的外植体,适宜的6-BA浓度(2.0 mg/L)可抑制褐变,添加活性炭和适宜的培养温度均能防止褐变死亡的发生。     

高速逆流色谱法制备分离库拉索芦荟中的2’-对香豆酰芦荟宁

采用高速逆流色谱法分离纯化库拉索芦荟中的2’-对香豆酰芦荟宁。以正己烷-乙酸乙酯-丙酮-水(1∶5∶1∶5,V/V/V/V)为溶剂体系,上相为固定相,下相为流动相,线圈转速为860 r/min,流速为2 mL/min,紫外检测波长为300 nm,一次进样85 min内从487.5 mg库拉索芦荟丙酮提取物中分离得到19.5 mg单体组分,经高效液相色谱分析,测定纯度为95.6%(峰面积百分比),通过质谱、红外、紫外和核磁技术进行结构鉴定,确定组分为2’-对香豆酰芦荟宁。该法具有操作简便、速度快、样品制备量大、节省溶剂及回收率高等优点,可为芦荟宁类化合物的分离提供高效、稳定及可靠的方法。     

Comparative efficiency of phosphate-solubilizing bacteria under greenhouse conditions for promoting growth and aloin-A content of Aloe barbadensis

This study was conducted with Aloe barbadensis in order to investigate the efficacy of four phosphate-solubilizing bacteria (PSB), Pseudomonas synxantha 10223, Burkholderia gladioli 10242, Enterobacter hormaechei 10240 and Serratia marcescens 10241 to solubilize Mussorie rock phosphate (MRP) and to evaluate its effects on growth, soluble P content and P uptake compared with control, i.e. uninoculated plants. Pot experiments were conducted in a greenhouse, in soil supplemented with MRP. Each PSB treatment showed different effects on different plant growth parameters. The maximum increase in leaf length (23.7%), total number of leaves (33.33%) and dry rind weight (69.10%) was observed in plants treated with P. synxantha 10223 compared with control. Whereas, maximum increase in root length (23.43%), fresh leaves weight (79.03%), dry gel weight (113.08%) and total gel volume (112.10%), was observed in plants treated with S. marcescens 10241 compared with uninoculated plants. Maximum increase in aloin-A content [114.92% (per g dry gel weight) and 322.32% (per plant dry gel weight)] was observed in plants treated with P. synxantha 10223 compared with control plants. Root colonization by inoculated PSB as estimated by RAPD technique showed that all PSB were able to survive in the rhizosphere of Aloe plants.     

芦荟的组织培养快速繁殖技术研究

以库拉索芦荟的叶片、茎段为外植体进行离体培养,结果表明,茎段可诱导形成愈伤组织,并分化出芽.以Ms为基本培养基,建立了库拉索芦荟的快速繁殖体系,其中以含BA 2.0mg@L-1,2,4-D 0.1 mg@L-1的培养基诱导分化频率较高;在芦荟组培苗的生根培养中,以含有IBA 1.0 mg@L-1的培养基生根效果较好.此外,还对芦荟组培苗的移栽条件及生长条件进行了研究,发现在锯末中的移栽效果较好,成活率可达90%以上.     

Characterization of phosphate solubilizing fluorescent pseudomonads from the rhizosphere of Aloe vera (L.)

Soil phosphorous (P) deficiency is a major constraint to plant production which is overcome by adding inorganic-phosphate as chemical fertilizers. Fluorescent pseudomonads are the diverse group of bacteria able to mobilize sparingly soluble phosphate form. Total three hundred seven fluorescent Pseudomonas isolates were obtained from the Aloe barbadensis (Miller) rhizosphere. These Pseudomonas strains were further evaluated in vitro for their ability to solubilize phosphate and to produce indole acetic acid (IAA), hydrogen cyanide (HCN), siderophore and 1-aminocyclopropane 1- carboxylate (ACC) deaminase. Fifty three (36.8%) isolates produced IAA and 52 (36.1%) isolates produced siderophores whereas 36 (25.0%) and 31 (21.5%) isolates produced HCN and ACC deaminase, respectively. A positive correlation existed between siderophore and ACC deaminase producers. Cluster analysis showed rhizosphere as the major factor influencing the ecological distribution and physiological characterization of phosphate solubilizing bacteria (PSB). Based on partial 16S rRNA gene sequencing PSB were identified as Pseudomonas putida, Pseudomonas sp. and Pseudomonas plecoglossicida with highest phosphate solubilization ability. In conclusion, these phosphate solubilizing fluorescent pseudomonads would help in understanding their role in phosphorus solubilization and identification of potent phosphorus solubilizers from the rhizosphere of commercially grown A. barbadensis.     

芦荟提取液抗菌效果研究

[目的]为芦荟在食品行业中的开发利用提供理论依据。[方法]以苯甲酸钠为对照,采用滤纸片法,研究美国库拉索芦荟(Aloe barbadensis Miller.)叶根部、叶中部、叶尖部的提取液对多种常见菌种的抑制作用及其热稳定性。[结果]不同部位芦荟提取液对金黄色葡萄球菌、大肠杆菌、黑曲霉都表现出了一定的抑菌作用,可媲美苯甲酸钠,对酿酒酵母的抑菌作用不是很明显。对于各种菌种来说,芦荟提取液抑菌作用的热稳定性良好,即使经过热处理也仍然保留良好的抗菌能力。[结论]芦荟提取液对多种细菌和霉菌有较强的抑菌作用,但对酿酒酵母没有抑制作用。     

氮磷钾肥对芦荟产量的影响

通过田间试验与定株观测的方法,研究了氮磷钾肥对芦荟生长发育和产量的影响.结果表明：氮磷钾配合施用与氮钾配合施用对芦荟叶长、叶数、单株重、叶产量均有显著的影响.氮磷钾配合施用3 a后,可使芦荟单株重达到12kg,芦荟叶产量达4.06kg/m2.     

Mn对芦荟根活力及活性物质含量的影响

[目的]研究Mn2＋浓度对库拉索芦荟根活力及体内芦荟苷、芦荟大黄素含量的影响。[方法]采用砂培试验。[结果]Mn2＋对芦荟根活力以及芦荟体内芦荟苷、芦荟大黄素含量均有影响。当营养液中Mn2＋浓度为1．0×10^-5mol／L时,芦荟根活力最高,芦荟苷和芦荟大黄素含量也最高;随着供Mn2＋浓度的提高,芦荟体内Mn2＋含量不断增加。[结论]为生产出活性成分含量高的芦荟奠定基础。     

库拉索芦荟大田杂草种类调查

为制定芦荟田杂草的防治措施,2007-2009年选择库拉索芦荟种植最适宜区云南元江县,应用最新的农田杂草评价体系对田间杂草种类进行调查,结果表明:库拉索芦荟田常见杂草有64种,隶属14科,主要杂草香附子、云南莎草、看麦娘.、无芒雀麦,在5-10月香附子、云南莎草、看麦娘、野稗、无芒雀麦、棒头草等大量发生,杂草随大田灌溉成阶段季节性发生.这一调查结果为库拉索芦荟田药剂防除杂草提供了科学依据.     

库拉索芦荟内生真菌类群与分布的初步研究

[目的]了解芦荟内生真菌的资源情况和种群多样性。[方法]对来自广东省新会、珠海、潮州、东莞、深圳以及广州市的番禺和黄埔的库拉索芦荟中内生真菌进行分离纯化,并通过诱导产孢试验对其进行分类鉴定。[结果]分别从210块芦荟叶组织和210块根组织中分离到27株和16株内生真菌,带菌率分别为12.86%和7.62%。形态学鉴定结果表明分离的内生真菌属于5个属。Aspergillus、Penicillium和Trichoderma的出现频率均大于0.95%,为芦荟内生真菌的优势种群,而Colletotrichum为新发现属。珠海和潮州的芦荟内生真菌最多,出现频率均为7.14%。从库拉索芦荟叶和根中均分离到Aspergillus和Penicillium,而Colletotrichum和Trichoderma只在芦荟叶中分离到,Chaetomium则只从根上分离到。[结论]不同地点和不同部位的库拉索芦荟组织内生真菌的类群与分布均存在明显差异。