Effects Of Potassium,Phosphorus And Nitrogen Fertilization On Endogenous Ethylene And Quality Characteristics Of Apples (Malus Domestica L.)

Factor analysis of the data from experiment one with fertilization of ‘Spartan’ apples using various levels of nitrogen, phosphorus, and potassium and their interactions showed significances between ethylene and potassium, soluble solids and potassium, acidity and phosphorus, ethylene and phosphorus, and between ethylene and nitrogen. Factor analysis of data from experiment two with twenty apple cultivars showed that maturation time and ethylene were positively associated, whereas ethylene was inversely related to acidity that is reduced during the apple fruit maturation, and soluble solids are produced during apple fruit maturation. The effects of potassium on ethylene could be through promotion of enzyme activation, promotion of protein synthesis and increased solute transport in the xylem and phloem. Production of ethylene through soluble solids could be due to increased synthesis of the amino acid cysteine that is precursor of ethylene that may be extended to synthesis of other amino acids. The decreasing concentration of malic acid during fruit maturation may be due to increasing rates of several enzymes involved in the citric acid and glyoxylate cycles that are delivering precursors to synthesis of amino acids and porphyrins. The significant relationships between soluble solids and potassium and between acidity and phosphorus may increase the synthesis of nucleic acids and improve energy supply through adenosine phosphates. The significance between ethylene and nitrogen may also increase synthesis of amino acids, proteins and enzymes. On this basis it may be concluded that the three major minerals nitrogen, phosphorus and potassium are very important for apple fruit maturation because they may be involved in several biochemical processes.     

小麦盐胁迫响应相关ERF基因的分离和初步验证

隶属于AP2/ERF超家族的乙烯响应因子(ERF)是植物抵御盐胁迫过程中的一类重要基因,为了减轻盐渍土地对小麦产量的负面影响,本研究从小麦全基因组中分离了AP2/ERF超家族,根据聚类结果和结构特征从中鉴定出96个ERF家族成员,在A、B、D基因组中共有229个拷贝序列;通过聚类分析和转录组数据分析筛选出13个与已克隆耐盐ERF基因相似性高或受NaCl诱导的TaERF成员,随后利用小麦抗感材料验证13个TaERF成员在受250 mmol·L^-1 NaCl处理后的表达水平变化情况,结果显示,TaERF27、TaERF35、TaERF55和TaERF64在耐盐材料CH7034中受NaCl胁迫后显著上调,而在盐敏感品种SY95-71中无明显变化,推测其可能为盐胁迫响应基因;组织特异表达和启动子调控元件分析结果显示这4个基因在CH7034苗期根和叶中均具有较高的表达水平,并且每个基因起始密码子前 2 000 bp区域内包含脱落酸、水杨酸和茉莉酸等多种植物激素响应元件,推测它们可能参与植物多种非生物胁迫信号转导通路。本研究结果有助于理解植株应对非生物胁迫的分子机制,并为小麦品种耐盐性改良提供了参考基因。     

EDTA一步提取法快速测定复混肥中有效五氧化二磷含量

采用乙二胺四乙酸二钠（EDTA）溶液直接提取复混肥中有效五氧化二磷,微波加热技术干燥磷钼酸喹啉沉淀。结果表明：用100 mL EDTA溶液（0.1 mL·L^-1）提取,在（80±2）℃恒温下振荡30 min,用微波炉加热干燥磷钼酸喹啉沉淀15 min的测定值,与标准方法测定值的绝对差值〈0.2%,该方法的相对偏差（RSD）〈0.2%,精密度和准确度良好。     

Synthesis and hydrophilicity of poly(trimethylene 2,6-naphthalate)/poly(ethylene glycol) copolymers

Poly(trimethylene 2,6-naphthalate) (PTN)/poly(ethylene glycol) (PEG) copolymers were synthesized by the two-step melt copolymerization process of dimethyl-2,6-naphthalenedicarboxylate (2,6-NDC) with 1,3-propanediol (PD) and PEG. The copolymers produced had different PEG molecular weights and contents. The structure, thermal property, and hydrophilicity of these copolymers were studied by proton nuclear magnetic resonance (¹H-NMR) analysis, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and by contact angle, moisture content, and instantaneous elastic recovery measurements. The intrinsic viscosity and the instantaneous elastic recovery of the PTN/PEG copolymers increased with increasing PEG molecular weight and content, whereas the glass transition, melting, and cold crystallization temperatures, and the heat of fusion of the PTN/PEG copolymers all decreased with increasing PEG molecular weight or content. The thermal stability of the copolymers was not affected by PEG molecular weight or content. The hydrophilicity, as determined by contact angle and moisture content measurements of the copolymer films, was significantly improved with increasing PEG molecular weight and content.     

Isothermal and non-isothermal shrinkage behaviors of highly oriented PET yarns

The isothermal and non-isothermal shrinkage behaviors of highly oriented Poly(ethylene terephthalate) yarns were investigated. In isothermal measurements, shrinkage and shrinkage stress firstly monotonously increased due to more and more activated frozen molecular segments with increasing time and temperature, and then relaxed at high temperature resulting from intermolecular slipping of micro-fibrils. According to the different contributions of amorphous and crystalline regions to shrinkage behavior, non-isothermal shrinkage and shrinkage stress curves were fitted by Gauss curves and the entire shrinkage process was divided into three stages: contraction of micro-fibrils, contraction of extended interfibrillar tie molecules and relative displacement of micro-fibrils.     

Copper metallization of poly(ethylene terephthalate) fabrics via intermediate polyaniline layers

Poly(ethylene terephthalate) fabrics were metallized through electroless plating of copper. The copper plating was performed on palladium-decorated polyaniline surfaces, and polyaniline was present as an intermediate layer on fabrics to facilitate palladium formation. Different oxidation states of polyaniline were tested in their efficacy in Pd (II) reduction and subsequent Cu plating. X-ray photoelectron spectroscopy was used to monitor the surface changes along the metallization procedure, and surface resistance was measure to probe the electrical properties of the metallized fabrics.     

乙烯对大豆产量及花器官发育的影响

    以大豆品种铁丰31为试验材料,探讨不同浓度乙烯抑制剂AVG(aminoethoxyvinylglycine)和促进剂ACC(1-aminocylopropane-1-carboxylic acid)对大豆花形态、花粉及单株产量等的影响.结果表明,供试品种经AVG处理后,与对照相比.成花量、花长度、花瓣长度、雄蕊柱长、花粉量、花粉管长度、秸杆重、单株荚数和单株产量随浓度增加而上升,花粉败育率下降,ACC处理的效果与AVG相反.两种处理对大豆花粉萌发率无明显影响.花粉扫描电镜结果显示,AVG处理的花粉长度增加,ACC处理的花粉部分出现扭曲与变形.     

毛白杨木材乙二醇醇解过程中木质素结构的FT-IR、1H NMR分析

为探讨木材乙二醇醇解过程中木质素结构的变化机理,以毛白杨磨木木质素(MWL)为研究对象,采用红外光谱和核磁共振等手段对醇解前后的木质素结构变化进行了分析.发现毛白杨木质素属于典型的愈创木基-紫丁香基型(GS型)木质素,G/S比值为1.37.醇解过程中木质素单元间β-O-4连接键大量断开,共轭羰基减少,甲基芳基醚键部分断开,产物中发现了大量新的酚羟基结构.醇解产生的低分子组分有芳香醚类、脂肪醚类、酚类、芳香酸类、不饱和酮类等物质.木质素大分子断裂的同时也有缩合反应发生.     

外源乙烯对甜瓜采后贮运性的影响

以新疆厚皮甜瓜为对象,通过不同浓度的外源乙烯处理甜瓜,以测定VC含量、可溶性固形物、可滴定滴定酸含量、果胶酶的活力、硬度、呼吸强度等的变化来研究外源乙烯对甜瓜的生理代谢的作用,结果表明:随着贮藏天数的增加,经外源乙烯处理的甜瓜,VC含量、可滴定酸、硬度都是呈下降趋势,且随乙烯浓度的增加,其下降幅度也相应增加,而呼吸速率、果胶酶活力和可溶性固形物,则呈抛物线形式,且随乙烯浓度的增加,其变化幅度也有所不同.总之,外源乙烯对甜瓜的品质会产生不良影响,在贮运过程中要及时去除.     

巴西橡胶树乳管生物学与胶乳生产

论述了3个限制天然橡胶生产的关键因素,即割胶后排胶持续的时间、两次割胶之间胶乳的再生和乳管从维管形成层的产生。同时说明,对橡胶树自身来说,乳管可能是与机械损伤相联系的一种保护组织,而乳管的形成和功能,能够被包括乙烯和茉莉酸在内的伤害信号高度地调节。