河西走廊不同产地‘赤霞珠’酿酒葡萄果实品质评价

为了确定河西走廊地区‘赤霞珠’酿酒葡萄核心品质指标,建立‘赤霞珠’酿酒葡萄品质综合评价模型。从张掖、武威、嘉峪关3个酿酒葡萄主产市的代表性果园采集6份‘赤霞珠’葡萄样品进行品质测定,通过主成分分析和聚类分析法确定‘赤霞珠’葡萄核心品质指标,运用层次分析法确定指标权重并建立‘赤霞珠’葡萄品质综合评价模型。结果表明:(1)不同产地‘赤霞珠’酿酒葡萄品质指标存在明显差异性,张掖市国风葡萄酒庄园的‘赤霞珠’葡萄果糖、蔗糖、草酸、柠檬酸含量均高于其他地区,且可溶性固形物、可溶性糖、总酚、苹果酸含量在各产地中也均保持在最高水平。(2)相关性分析发现,葡萄果实葡萄糖含量与可溶性固形物含量、果糖与可溶性糖含量之间呈极显著正相关,固酸比和糖酸比均与可滴定酸含量呈极显著负相关关系。(3)综合主成分分析、聚类分析和相关性分析结果,确定维生素C(Vc)、单宁、果糖和固酸比是‘赤霞珠’葡萄核心品质指标,应用层次分析法建立了‘赤霞珠’葡萄品质综合评价模型为Y=0.0960×Vc含量+0.1611×单宁含量+0.2771×果糖含量+0.4568×固酸比(各指标含量均经过标准化处理)。研究发现,河西走廊地区‘赤霞珠’葡萄果实品质最佳产地是张掖市,果实Vc、单宁、果糖和固酸比是‘赤霞珠’葡萄的核心品质指标,以其建立的评价模型可用于‘赤霞珠’葡萄品质的综合评价。     

‘黑杞一号’与野生黑果枸杞的酚类物质分析

以‘黑杞一号’和野生黑果枸杞为研究对象,对其总酚、总花色苷、总单宁、单体花色苷和非花色苷单体酚类物质进行测定分析。结果表明:(1)与野生黑果枸杞相比,‘黑杞一号’的总酚、总花色苷、总单宁含量分别高出14 250、390和3 330μg/g。(2)‘黑杞一号’和野生黑果枸杞中均检测出4种单体花色苷,包括双葡萄糖苷1种、咖啡酰化葡萄糖苷2种和香豆酰化葡萄糖苷1种,且‘黑杞一号’的4种单体花色苷均显著高于野生黑果枸杞,其中单体花色苷总量比野生黑果枸杞高116.88%(5 672.8μg/g),二甲花翠素咖啡酰化葡萄糖苷含量为野生黑果枸杞的14.93倍。(3)‘黑杞一号’和野生黑果枸杞中均检测到29种非花色苷单体酚,包括黄烷醇类7种、羟基苯甲酸类4种,黄酮醇类18种,并以原儿茶酸含量最高,但‘黑杞一号’非花色苷单体酚总量较野生黑果枸杞低51.42%(2.71μg/g)。     

野生葡萄及葡萄酒抗氧化活性和抗菌性研究

选取广西、湖南等地野生葡萄,与经典酿酒葡萄比较,研究抗氧化活性和活性物质,同时监测葡萄酒发酵过程中各指标的动态变化,并对不同品种葡萄酒的抗菌性进行研究。结果表明:赤霞珠的酚类含量和抗氧化活性高于野生葡萄和玫瑰香葡萄,但野生葡萄酒的抗菌性能显著优于赤霞珠和玫瑰香葡萄酒。葡萄酒在发酵过程中其抗氧化活性和酚类物质含量均随发酵过程的进行而升高;总抗氧化活性与总酚含量、氧自由基清除能力与原花青素含量成显著正相关,相关系数均大于0.989;总花色苷含量在发酵初期上升,后期下降,葡萄酒颜色变浅。     

香雪兰花瓣的花色苷组成

为研究不同品种香雪兰的花色苷组成、含量及与花色表型之间的关系,阐明香雪兰花色形成机理,该研究以不同花色的香雪兰(Freesia hybrida) 11个品种为材料,采用英国皇家园艺学会比色卡(RHSCC)和色差仪进行花色描述,利用特征颜色反应初步确定色素类型,通过pH示差法测定花瓣中总花色苷的含量,进而利用UPLC-Q-TOF-MS技术分析各品种花瓣中花色苷种类和相对含量。结果表明:11个所选品种涵盖香雪兰四大色系,即白色系、黄色系、红色系、蓝紫色系;所选品种都含有黄酮类化合物,不含或含有极低量的类胡萝卜素,除‘White River’‘Fragrant Sunburst’‘Gold River’‘Tweety’外,均含有花色苷;‘Red Passion’花瓣中总花色苷含量最高,最低是‘Lovely Lavender’,其含量仅为‘Red Passion’的24%;在香雪兰花瓣中共检测出10个花色苷组分,分别为飞燕草-二葡萄糖苷、矢车菊素-二葡萄糖苷、矮牵牛素-二葡萄糖苷、飞燕草素-3-O-葡萄糖苷、矢车菊素-3-O-葡萄糖苷、芍药素-二葡萄糖苷、锦葵素-二葡萄糖苷、矮牵牛素-3-O-葡萄糖苷、芍药素-3-O-葡萄糖苷、锦葵素-3-O-葡萄糖苷;红色系品种‘Red Passion’和‘上农红台阁’花瓣中主要成分为矢车菊素类化合物,蓝紫色系品种‘Pink Passion’‘Castor’‘上农淡雪青’和‘上农紫玫瑰’花瓣中主要成分为矮牵牛素类和锦葵素类化合物,‘Lovely Lavender’花瓣仅含飞燕草素类化合物。研究表明不同品种香雪兰花瓣颜色的呈现与花色苷种类有关,花瓣着色程度则与花瓣中花色苷总含量成正比。该研究结果为新品种培育、花色改良和育种工作提供理论依据。     

“赤霞珠”葡萄营养系果实中黄酮类物质变化研究

黄酮类物质是葡萄与葡萄酒中重要的生理活性物质,对葡萄酒的感官品质起决定作用。以酿酒葡萄"赤霞珠"(Cabernet Sauvignon,CS)5个营养系为试验材料,分析黄酮类物质的含量差异,为提高黄土高原产区葡萄酒品质提供材料。结果表明:在转色后80 d时"赤霞珠"葡萄营养系可溶性固性物和可滴定酸含量差异不显著,而CS191平均单粒重显著高于其他4个营养系。CS191在转色后80 d时,果皮和种子中总类黄酮、原花色素含量显著高于其他营养系。在转色后80 d时,营养系间果皮中黄烷醇含量差异不显著,但此时期CS170果皮中黄烷醇含量显著高于其他4个营养系。CS191在完熟时果实中总类黄酮和原花色素含量高于其他营养系,CS170果皮中黄烷醇和花色苷含量较其他营养系含量高,均可作为黄土高原地区栽培的高黄酮物质含量的"赤霞珠"品系。     

‘脆红李’果实发育过程中花色苷含量及相关基因表达分析

花色苷是一类重要的色素,对李红色的形成必不可少。本研究以‘脆红李’为试材,研究了果实发育过程中叶绿素含量、总花色苷含量及果皮主要花色苷组分和含量的变化规律,并分析了Ps PAL、Ps CHS、Ps CHI、Ps F3H、Ps DFR、Ps ANS和Ps UFGT基因在果实不同发育阶段的表达规律。结果表明,随着‘脆红李’果实的生长发育,果皮和果肉中总叶绿素含量呈逐渐下降的趋势;‘脆红李’果肉中不含花色苷,果皮中的花色苷在转色期才开始积累,成熟时达到最大值,为404.37μg/(g·FW),并以矢车菊素-3-O-葡萄糖苷和矢车菊素-3-O-芸香糖苷为主;花色苷合成相关基因在‘脆红李’不同生长发育时期的果皮和果肉中有着特异性的表达,但只有Ps PAL和Ps UFGT基因的转录水平与花色苷含量的正相关性达到极显著水平,表明这两个基因对‘脆红李’果实的着色有着异常重要的调控作用。     

果袋类型对‘紫金红霞’葡萄果实品质及花色苷合成相关基因表达的影响

以‘紫金红霞’葡萄为试验材料,在果实转色前分别进行5种不同类型果袋(白色纸袋、无纺布 白纸双层袋、绿色纸袋、蓝色纸袋、棕色纸袋)套袋处理,以不套袋为对照,测定不同发育时期葡萄果实的单果重、果粒纵横径、可溶性固形物、可滴定酸,及总花色苷含量等生理指标,并利用qRT PCR技术分析不同发育时期花色苷合成相关基因的表达水平,探索不同类型果袋对‘紫金红霞’葡萄果实品质、花色苷含量及花色苷合成相关基因表达的影响。结果表明：(1)白色、蓝色和棕色果袋不利于成熟果实中可溶性固形物含量的升高,蓝色和棕色果袋不利于成熟果实中可滴定酸含量的降低。(2)套袋处理会使果实色泽指数显著降低,除无纺布 白纸双层袋未显著降低成熟期果皮中花色苷含量外,其他套袋处理均显著降低了果皮中总花色苷含量。(3)套袋处理对6个花色苷合成相关基因的表达主要表现为抑制作用,但无纺布 白纸双层袋对成熟期F3′H和UFGT基因的表达、白色纸袋对成熟期MYBA1、DFR和LDOX基因的表达则具有促进作用。研究发现,无纺布 白纸双层袋对成熟期果实的内在品质和果皮着色影响最小,可用于‘紫金红霞’果实套袋,其次为白色和绿色纸袋;蓝色和棕色纸袋可使葡萄果实的品质大幅降低,故不可用于实际生产中葡萄果实的套袋。     

贺兰山东麓‘马瑟兰’葡萄果实花色苷和原花色素特性分析北大核心CSCD

为了更好地了解宁夏贺兰山东麓不同区域酿酒葡萄‘马瑟兰’果实的花色苷和原花色素特性，以及综合品质的区域差异性，为该品种在贺兰山东麓产区的推广和栽培管理提供参考。研究以银川、农垦玉泉营、青铜峡和红寺堡4个子产区10个代表性酒庄的‘马瑟兰’葡萄为试材，通过偏最小二乘法判别分析(PLS-DA)筛选造成酒庄间果实品质差异的酚类物质指标，并采用主成分分析法(PCA)对不同酒庄‘马瑟兰’果实品质进行综合评价。结果表明，(1)10个酒庄‘马瑟兰’果实的基本理化指标、花色苷和原花色素组分与含量均存在差异，H-Hs酒庄葡萄果皮的花色苷和原花色素含量均为最高，分别达到111.91 mg/g和35.68 mg/g; Y-Mq酒庄葡萄种子原花色素含量最高(108.67 mg/g)。(2)基于果实花色苷和原花色素特性，采用聚类分析将10个酒庄划分为4类，其中H-Hs酒庄单独为一类，且能很好地与其他酒庄分开。(3)PLS-DA分析表明，种子原花色素的表儿茶素没食子酸酯末端亚基(ECG-p)和表儿茶素末端亚基(EC-p)所占摩尔百分比、果皮总花色苷含量和非酰化花色苷含量、果皮原花色素的EC-p所占摩尔百分比是区分10个酒庄果实品质差异的主要指标。(4)PCA分析表明，果实品质综合评价排名前三的酒庄为红寺堡子产区的H-Hs、银川子产区的Y-Mq和青铜峡子产区的Q-H酒庄。可见，贺兰山东麓‘马瑟兰’葡萄果实花色苷和原花色素特性及综合品质表现出明显的产地差异性，并以红寺堡子产区表现较佳。     

2个石榴品种果皮花色苷合成相关基因表达分析

以2个不同红色石榴品种‘红宝石’和‘墨石榴’为试验材料,采用荧光定量PCR方法,分析花色苷合成相关基因CHS、CHI、F3H、DFR、ANS、UFGT等6个基因在果实发育过程中的转录表达特性,同时分析基因表达量与果皮花色苷积累的关系。结果表明:(1)在整个果实发育期内‘墨石榴’花色苷含量明显高于‘红宝石’;随着果实的发育,‘红宝石’果皮中总花色苷含量不断增加,而‘墨石榴’中总花色苷含量初期很高,随后迅速下降,后期维持在较低水平。(2)‘红宝石’中CHS、CHI、F3H、DFR、UFGT等5个基因均在果实发育的早期和晚期出现2个表达高峰,而ANS基因的表达量在整个果实发育期内不断升高;在‘墨石榴’中CHS、CHI、F3H、DFR、ANS等5个基因的表达高峰均出现在早期,随着果实的发育表达量均呈下降变化趋势,但UFGT基因在中期时表达量最高。(3)‘红宝石’石榴的ANS基因表达量与总花色苷含量呈显著正相关,‘墨石榴’中CHS和ANS基因的表达水平与总花色苷含量显著相关。研究认为,花色苷合成相关基因的初期和末期表达差异是2个石榴品种着色差异的主要原因,ANS在‘红宝石’着色中起关键作用,CHS和ANS可能在‘墨石榴’花色苷积累中起重要作用。     

小苍兰花瓣主要花色苷组分研究

以6个小苍兰(Freesia hybrida)园艺品种为研究材料,采用英国皇家园艺学会比色卡进行花色描述,利用特征颜色反应确定其色素类型,进而通过UPLC-PAD结合UPLC-Q-TOF-MS技术分析各品种中的花色苷种类及含量。结果表明,6个小苍兰品种可分为白色系、橙—黄色系以及紫—紫红—蓝紫系三大色系。小苍兰6个品种花瓣中均含有黄酮类色素,不含或含极低量类胡萝卜素,除‘上农乳香’以外,其余品种花瓣中均含有花色苷。花瓣中花色苷含量依小苍兰品种不同而各异,5个含花色苷的品种中,‘上农紫玫瑰’花瓣中花色苷含量最高,‘上农橙红’次之。在小苍兰花瓣中,共检测到6种花色苷物质,通过与已有文献比对分析,推定其成分为:飞燕草3,5-二葡萄糖苷、矮牵牛素3,5-二葡萄糖苷、飞燕草3-葡萄糖苷、锦葵素3,5-二葡萄糖苷、牵牛花素3-葡萄糖苷和锦葵素3-葡萄糖苷。‘上农紫雪青’和‘上农宫粉’花瓣中含有3种花色苷,且均含锦葵素类和矮牵牛素类,其中‘上农紫雪青’花瓣中主要成分是锦葵素单糖苷和双糖苷;而‘上农宫粉’花瓣中则均为双糖花色苷,主要成分是矮牵牛素3,5-二葡萄糖苷、锦葵素3,5-二葡萄糖苷和飞燕草3,5-二葡萄糖苷;‘上农紫玫瑰’花瓣中含矮牵牛素3-葡萄糖苷和飞燕草3-葡萄糖苷;而‘上农金皇后’和‘上农橙红’花瓣中仅含一种组分,分别为飞燕草3,5-二葡萄糖苷和锦葵素3,5-二葡萄糖苷。     

壳聚糖酶的克隆表达与壳寡糖的制备分析

目的:克隆壳聚糖酶基因于大肠杆菌中实现高表达,制备壳寡糖。方法:以枯草芽孢杆菌总DNA为模板扩增壳聚糖酶基因(CSN),克隆至载体pET23a(+)上,转化菌株BL21(DE3)。重组子经0.5 mmol/L IPTG诱导后,SDS-PAGE和质谱检测与鉴定重组酶。酶纯化后水解壳聚糖,薄层色谱分析其水解产物。结果:质谱证明壳聚糖酶(31.5kDa)成功表达,表达量占菌体总蛋白的45%左右。纯化后重组酶浓度为900 mg/L,纯度95%、回收率85%,酶活力为10 000 U/mg。壳聚糖降解产物为壳二糖至壳四糖。结论:原核表达载体pET23a(+)-CSN构建正确,壳聚糖酶表达量与活性高,适用于水解壳聚糖制备壳寡糖。     

国内外蝗害治理技术现状与展望

本文首先概述了国内外蝗虫发生与为害的态势,总结了现阶段我国蝗虫发生与为害的主要特点:即农田飞蝗暴发频繁而且严重,草原土蝗的发生时常造成严重的经济损失,而且侵入城市干扰市民生活,我国与周边国家之间蝗虫过境迁移频繁,使用化学农药污染环境和农产品;分析了国内外蝗虫防治对策与技术的发展现状,重点介绍了应急防治和可持续治理对策、...     

Coiled-coil nanomechanics and uncoiling and unfolding of the superhelix and alpha-helices of myosin

The nanomechanical properties of the coiled-coils of myosin are fundamentally important in understanding muscle assembly and contraction. Force spectra of single molecules of double-headed myosin, single-headed myosin, and coiled-coil tail fragments were acquired with an atomic force microscope and displayed characteristic triphasic force-distance responses to stretch: a rise phase (R) and a plateau phase (P) and an exponential phase (E). The R and P phases arise mainly from the stretching of the coiled-coils, with the hinge region being the main contributor to the rise phase at low force. Only the E phase was analyzable by the worm-like chain model of polymer elasticity. Restrained molecular mechanics simulations on an existing x-ray structure of scallop S2 yielded force spectra with either two or three phases, depending on the mode of stretch. It revealed that coiled-coil chains separate completely near the end of the P phase and the stretching of the unfolded chains gives rise to the E phase. Extensive conformational searching yielded a P phase force near 40 pN that agreed well with the experimental value. We suggest that the flexible and elastic S2 region, particularly the hinge region, may undergo force-induced unfolding and extend reversibly during actomyosin powerstroke.     

放牧对牧草光合作用、呼吸作用和氮、碳吸收与转运的影响

研究放牧对草地植物生理活动的影响,对于揭示草地放牧演替的生理机制有重要意义.大量研究表明,家畜放牧对牧草光合作用、呼吸作用以及C和N吸收与转运的影响,可以分为生理伤害和生理恢复2个阶段.放牧通过改变草地冠层结构影响牧草光合作用,净光合作用速率短期内迅速下降,随着叶面积指数增加又逐渐上升,呼吸作用有相似的变化趋势.牧草放牧后再生长所需的C和N最初主要来自根系和留茬中的贮藏物质,此后随着牧草生长恢复逐渐由同化作用供给,C代谢与土壤N水平负相关.放牧后牧草生理活动变化与牧草遗传特性、种间竞争、家畜放牧特征、非生物环境等因素密切相关.     

Synthesis of hapten and conjugates of coumestrol and development of immunoassay

3-O-Carboxymethylcoumestrol was prepared as the hapten for immunoassay by a partial alkylation of coumestrol with ethyl chloroacetate in acetone alkalized with potassium carbonate. 3-O-Ethoxycarbonylmethylcoumestrol was separated by column chromatography and finally was hydrolyzed with formic acid. 1H and 13C NMR data (APT, COSY, HMQC, and HMBC) revealed that the reaction was regioselective, as 3-O-ethoxycarboxymethylcoumestrol was the only monosubstituted derivative. The hapten was then conjugated to bovine serum albumin and used for immunization of rabbits. A radioimmunoassay (RIA) system was established based on the polyclonal antiserum and a 125I-labeled hapten-tyrosine methyl ester conjugate as the radioligand. Parameters of the RIA: sensitivity: 12 pg per tube, 50% intercept: 140 pg per tube, working range: 20-4000 pg per tube. The cross-reactivity of a panel isoflavonoid and lignan phytoestrogens was either negligible (e.g. formononetin 0.07%; biochanin A 0.06%) or not detectable at all. The major immunoreactive peak in HPLC fractions from an alfalfa extract had the same retention time as coumestrol standard and represented 94.8% of the signal. The remaining 5.2% of immunoreactivity was distributed between five minor peaks. We conclude that after the validation for particular matrices, the method will be a useful tool for analysis of coumestrol, especially in low volume and low concentration samples.     

Kinetics and thermodynamics of peroxidase- and laccase-catalyzed oxidation of N-substituted phenothiazines and phenoxazines

N -substituted phenothiazines (PTs) and phenoxazines (POs) catalyzed by fungal Coprinus cinereus peroxidase and Polyporus pinsitus laccase were investigated at pH 4–10. In the case of peroxidase, an apparent bimolecular rate constant (expressed as k _cat/K _m) varied from 1 ×10⁷M⁻¹s⁻¹to 2.6×10⁸M⁻¹s⁻¹ at pH 7.0. The constants for PO oxidation were higher in comparison to PT. pH dependence revealed two or three ionizable groups with pK _a values of 4.9–5.7 and 7.7–9.7 that significantly affected the activity of peroxidase. Single-turnover experiments showed that the limiting step of PT oxidation was reduction of compound II and second-order rate constants were obtained which were consistent with the constants at steady-state conditions. Laccase-catalyzed PT and PO oxidation rates were lower; apparent bimolecular rate constants varied from 1.8×10⁵M⁻¹s⁻¹ to 2.0×10⁷M⁻¹s⁻¹ at pH 5.3. PO constants were higher in comparison to PT, as was the case with peroxidase. The dependence of the apparent bimolecular constants of compound II or copper type 1 reduction, in the case of peroxidase or laccase, respectively, was analyzed in the framework of the Marcus outer-sphere electron-transfer theory. Peroxidase-catalyzed reactions with PT, as well as PO, fitted the same hyperbolic dependence with a maximal oxidation rate of 1.6×10⁸M⁻¹s⁻¹ and a reorganization energy of 0.30 eV. The respective parameters for laccase were 5.0×10⁷M⁻¹s⁻¹ and 0.29 eV. Received: 20 September 1999 / Accepted: 24 February 2000     

白术同源四倍体的诱导和鉴定及其与二倍体过氧化物酶的比较

以白术（Atractylodes macrooephala Koidz.）二倍体组培苗为材料,对其四倍体诱导方法进行研究,共获得45个白术同源四倍体株系,为优良株系的选育提供了材料。此外,还分析比较了其中8个白术四倍体株系与二倍体的过氧化物酶同工酶（POD）的酶谱差异,发现四倍体各株系过氧化物酶同工酶谱比二倍体的均多了Rf0.310的谱带,且总过氧化物酶比活力也发生了很大改变,对探讨白术四倍体优良株系的生理生化机理具有一定的参考价值。     

Morphology and putative function of the colon and cloaca of marine and freshwater snakes

Among tetrapods, evidence for postrenal modification of the urine by the distal digestive tract (including the colon and cloaca) is highly variable. Birds and bladderless reptiles are of interest because the colon and cloaca represent the only sites from which water and ions can be reclaimed from the urine secreted by the kidney. For animals occupying desiccating environments (e.g., deserts and marine environments), postrenal modification of the urine may directly contribute to the maintenance of hypo‐osmotic body fluids. We compared the morphology and distribution of key proteins in the colon, cloaca, and urogenital ducts of watersnakes from marine (Nerodia clarkii clarkii) and freshwater (Nerodia fasciata) habitats. Specifically, we examined the epithelia of each tissue for evidence of mucus production by examining the distribution of mucopolysaccharides, and for evidence of water/ion regulation by examining the distribution of Na⁺/K⁺‐ATPase (NKA), Na⁺/K⁺/Cl^? cotransporter (NKCC), and aquaporin 3 (AQP3). NKCC localized to the basolateral epithelium of the colon, urodeal sphincter, and proctodeum, consistent with a role in secretion of Na⁺, Cl^?, and K⁺ from the tissue, but NKA was not detected in the colon or any compartment of the cloaca. Interestingly, NKA was detected in the basolateral epithelium of the ureters, suggesting the urothelium may play a role in active ion transport. AQP3 was detected in the ureters and coprodeal complex, consistent with a role in urinary and fecal dehydration or, potentially, in the production of the watery component of the mucus secreted by the coprodeal complex. Since no differences in general cloacal morphology, production of mucus, or the distribution of ion transporters/water channels were detected between the two species, cloacal osmoregulation may either be regulated by proteins not examined in this study or may not be responsible for the differential success of N. c. clarkii and N. fasciata in marine habitats. J. Morphol. 2011. © 2011 Wiley Periodicals, Inc.