行间生草对赤霞珠葡萄与葡萄酒中主要单体酚的影响

 【目的】研究葡萄园行间生草对葡萄果实与葡萄酒中主要单体酚含量的影响。【方法】在酿酒品种赤霞珠葡萄园行间播种白三叶草、紫花苜蓿和高羊茅,以清耕为对照,在果实成熟期及酒精发酵结束后,采用有机溶剂萃取、HPLC定性与定量分析各处理葡萄与葡萄酒中的主要单体酚含量。【结果】在赤霞珠葡萄果实与葡萄酒中共检测出10种单体酚,包括非类黄酮和类黄酮类,葡萄与葡萄酒中类黄酮类多酚的总含量(409.43～538.63 mg?kg-1和56.16～81.30 mg?L-1)高于非类黄酮(76.91～98.85 mg?kg-1和30.65～41.22 mg?L-1)。在类黄酮中,黄烷醇类儿茶素含量及所占比例最高,葡萄果实及葡萄酒中儿茶素的含量分别占所测单体酚总含量的74.94%～79.70%和48.60%～50.62%。与清耕(对照)相比,行间生草可提高葡萄果实与葡萄酒中主要单体酚的含量及其总量,其中高羊茅和白三叶草处理葡萄果实中安息香酸、水杨酸、咖啡酸、儿茶素含量及单体酚总含量与清耕(对照)之间差异达显著或极显著水平;同时高羊茅处理使葡萄酒中没食子酸、咖啡酸、儿茶素等含量显著升高,在葡萄果实与葡萄酒中各处理单体酚总含量由高到低均为高羊茅?白三叶草?紫花苜蓿?清耕(对照)。【结论】行间生草可提高葡萄与葡萄酒中多酚化合物的含量,从而提高葡萄酒的质量。     

行间生草对赤霞珠葡萄与葡萄酒含氮化合物的影响

【目的】研究葡萄园行间生草对葡萄果实不同部位与葡萄酒中含氮化合物的影响。【方法】在酿酒品种赤霞珠葡萄园行间播种白三叶草、紫花苜蓿和高羊茅,以清耕为对照,在果实成熟期及酒精发酵结束后,采用凯氏定氮法及全自动氨基酸分析仪测定分析各处理葡萄果皮、果肉、种子及葡萄酒中的总氮、可溶性蛋白质及氨基酸含量。【结果】除紫花苜蓿处理使葡萄种子中可溶性蛋白质含量显著高于清耕(对照)外,行间生草总体使葡萄果皮、果肉及种子中的总氮和可溶性蛋白质含量降低,果实中不同部位总氮及可溶性蛋白质含量也有差异,种子中总氮含量最高,占葡萄果实总氮含量的41.6%,果肉与果皮分别占总氮含量的33.9%及24.5%;葡萄果实中可溶性蛋白质占总氮含量的46.0%,种子、果肉及果皮中可溶性蛋白质分别占果实中可溶性蛋白质总含量的50.9%、33.9%及15.2%;葡萄酒中总氮和可溶性蛋白质含量无显著差异。高羊茅和紫花苜蓿处理使葡萄果实中氨基酸总含量升高,白三叶草处理使其降低,但均无显著差异,各处理葡萄果实中均以脯氨酸含量最高,占氨基酸总含量的45.9%—56.9%,其次是赖氨酸和精氨酸,占氨基酸总含量的16.4%—24.2%。行间生草使葡萄酒游离氨基酸总含量升高,其中高羊茅处理最高,其次是紫花苜蓿处理,这两种生草处理与清耕之间差异达显著水平;各处理葡萄酒中的氨基酸,均以脯氨酸含量最高,占氨基酸总含量的90.11%—92.45%。【结论】行间生草使葡萄果实总氮和可溶性蛋白质含量降低,但总体提高了葡萄与葡萄酒中游离氨基酸总含量,有利于提高葡萄酒的质量。     

架式与新梢留量对赤霞珠葡萄酒中单体酚的影响

【目的】研究架式与新梢留量对葡萄酒中单体酚的影响。【方法】以赤霞珠为试材,采用HPLC分析法,研究不同新梢留量、单篱架与“V”形架栽培条件下所酿干红葡萄酒中单体酚的种类及含量。新梢处理设3个水平,分别为每延长1 m架面留新梢10、13和16个。【结果】(1)单体酚总量随单位新梢留量的降低而增加(119.08—146.40 mg•L-1),且各处理间存在极显著差异;“V”形架栽培下的葡萄酒单体酚总量(133.47 mg•L-1)高于单篱架(119.08 mg•L-1)。(2)各处理条件下葡萄酒中非类黄酮含量(100.13—123.46 mg•L-1)均高于类黄酮含量(17.08—25.25 mg•L-1),前者占单体酚总量的81.08%—85.66%,后者占14.34%—18.92%。(3)各处理条件下均可检出待测10种单体酚,类黄酮类物质以儿茶素为主,非类黄酮类物质以没食子酸为主。【结论】降低赤霞珠葡萄单位面积留梢量可提高葡萄酒中单体酚的含量;“V”形架栽培可提高葡萄酒中单体酚的含量。     

Construction of Prokaryotic Expression Vector of Mouse Nanog Gene and Its Expression

The aim of this study is to construct a prokaryotic expression vector of mouse Nanog gene and to express it in E. coli. A pair of primers was designed according to digestion sites in plasmid pGEX-KG and the Nanog gene sequence published by GenBank. The DNA fragment of 918 bp was amplified by polymerase chain reaction （PCR） from the pNA992 recombinant plasmid with Nanog gene, then cloned into pGEX-KG and transformed into the host E. coli strain TG Ⅰ. The sequence of the fragment was matched with the original sequence of pNA992. It indicated that fusion expression vector, pGEX-KG- Nanog, was constructed successfully. The pGEX-KG-Nanog plasmid was extracted from E. coli strain TG Ⅰ and was transformed into BL21（DE3） for expression. After induction by isopropyl-β-D-thiogalactoside （IPTG） at 37℃, the expression product of Nanog gene was identified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis （SDS-PAGE）, and the expression condition was optimized. Nanog fusion protein was successfully expressed in the form of inclusion bodies. The molecular weight of the inclusion body was 63 kDa. Meanwhile, the optimum condition for the expression of Nanog fusion protein was induced with 0.8 mmol L^-1 IPTG for 5 h. The mouse Nanog gene was successfully expressed in E. coli, which laid a foundation for the purification of Nanog protein and for the preparation of polyclonal antibody.     

Establishment of a Gene Expression System in Rice Chloroplast and Obtainment of PPT-Resistant Rice Plants

In contrast to the situation of random integration of foreign genes in nuclear transformation, the introduction of genes via chloroplast genetic engineering is characterized by site-specific pattern via homologous recombination. To establish an expression system for alien genes in rice chloroplast, the intergenic region of ndhF and trnL was selected as target for sitespecific integration of PPT-resistant bar gene in this study. Two DNA fragments suitable for homologous recombination were cloned from rice chloroplast genome DNA using PCR technique, and the chloroplast-specific expression vector pRB was constructed by fusing a modified 16S rRNA gene promoter to bar gene together with terminator ofpsbA gene 3 sequence. Chloroplast transformation was carried out by biolistic bombardment of sterile rice calli with the pRB construct. Subsequently, the regenerated plantlets and seeds of progeny arising from reciprocal cross to the wild-type lines were obtained. Molecular analysis suggested that the bar gene has been integrated into rice chloroplast genome. Genetic analysis revealed that bar gene could be transmitted and expressed normally in chloroplast genome. Thus, the bar gene conferred not only selection pressure for the transformation of rice chloroplast genome, but PPT-resistant trait for rice plants as well. It is suggested that an efficient gene expression system in the rice chloroplast has been established by chloroplast transformation technique.     

葡萄园行间生草对'赤霞珠'干红葡萄酒质的影响

 在葡萄品种'赤霞珠'生产园行间播种多年生黑麦草、紫花苜蓿、白三叶草，在葡萄果实成熟过程中分析其含糖量和含酸量的变化趋势，并进行酿酒试验及葡萄酒理化指标分析和感官品评，以探讨行间生草对'赤霞珠'干红葡萄酒质量的影响。结果表明，与清耕相比，行间生草可使葡萄果实还原糖含量增加，含酸量降低；葡萄酒中pH值、花色素苷、单宁含量升高，酒体颜色加深，结构感增强。因此，行间生草使'赤霞珠'葡萄果实及葡萄酒品质提高。     

干旱区赤霞珠葡萄着色期含糖量变化及其数学模型研究

[目的]研究干旱区赤霞珠葡萄(Vitis vinifera L.cv.‘Cabernet Sauvignon’)着色期含糖量的变化规律,并拟合其数学模型。[方法]对干旱区栽培的赤霞珠葡萄,在着色期进行定期多点测定含糖量。[结果]赤霞珠葡萄可溶性固形物含量的增加有2个明显不同的阶段,其中以第1阶段增长最快,可溶性固形物增量占采收时总含糖量的27.1%,日均增糖量为0.32%,为葡萄果实快速增糖期。而且U型架比篱架含糖量增加0.20～1.50个百分点。数学模型验证表明,赤霞珠葡萄含糖量增加的规律符合直线回归方程。[结论]该研究可为确定葡萄适宜的采收期,为酿酒葡萄的优质高效丰产提供理论依据。     

Comparative Analysis of Population Genetic Structure in Bemisia tabaci (Gennadius) Biotypes B and Q Based on ISSR Marker

Bemisia tabaci (Gennadius) biotypes B and Q are two invasive biotypes in the species complex. The comparison of the population genetic structure of the two biotypes is of significance to show their invasive mechanism and to their control. The intersimple sequence repeats (ISSR) marker was used to analyze the 16 B-biotype populations and 4 Q-biotype populations worldwide with a Trialeurodes vaporariorum population in Shanxi Province, China, and a B. tabaci non-B/Q-biotype population in Zhejiang Province, China, was used as control populations. The analysis of genetic diversity showed that the diversity indexes of biotype Q including Nei's gene diversity index, Shannon informative index, and the percentage of polymorphic loci were higher than those of biotype B. The high genetic diversity of biotype Q might provide the genetic basis for the excellent ecological adaptation. Cluster analysis suggested that the ISSR could not be used in the phylogenetic analysis though it could easily distinguish the biotypes of B. tabaci. The difference of the population genetic structure between the biotype B and the biotype Q exists based on the ISSR marker. Meanwhile, the results suggested that the molecular marker has its limitation in the phylogenetic analysis among the biotypes of B. tabaci.