基于WebGIS的植物园植物物种管理信息系统

鉴于植物园现代化管理和国内外植物资源信息交流的迫切需要,利用WebGIS系统集成技术在Internet上建立了中国科学院武汉植物园植物物种管理信息系统。系统实现了基于网络的图形属性数据的双向查询,并具有新增、编辑、缩放、漫游、定位等功能,为植物迁地保育的动态管理提供了管理工具,为科研、科普等应用部门和科技人员提供了获取植物物种信息的工作平台。文中详细介绍了该系统的设计要求、数据来源、开发运行环境、数据库构成、系统功能等。     

Monitoring and Risk Assessment of Pesticide Residues in Tea Samples from China

In the present study an effort was made to monitor the residue levels of 32 pesticides in tea samples collected from three representative tea districts of China during 2010 to 2012. A total of 223 samples of green tea, pu-erh tea, black tea, and oolong tea were determined using gas chromatography with mass spectrometry (GC-MS). Among 223 samples, 198 samples contained pesticide residues, and 39 samples had residue levels that were more than the European Union (EU) maximum residue limits (MRLs). The most positive and violated MLRs were observed in Oolong tea. The highest detection rates and the most often exceeding the MRLs were observed for the residues of bifenthrin. Ten pesticides were not found in the 223 tea samples. The potential health risks to consumers due to tea consumption in three representative cities were estimated. The results suggested that non-cancer hazards of organophosphorus, organochlorines, and pyrethroids and the cancer risks from exposure to hexachlorobenzene, heptachlor, chlordane, and pp’-DDT were clearly below the safe limit. Nevertheless, an investigation into continuous monitoring and tighter regulation of pesticide residues in tea samples are almost always desirable or even necessary for public health protection.     

间作密植和单行茶园节肢动物群落组成差异

1998年1－12月每月下旬,对皖南敬亭山茶场栗－茶间作,梨－茶间作,3行密植和单行条植茶园节肢动物群落的调查表明：植食性昆虫种数分别占各类型茶园总物种数51．9％,53．6％,54．4％和56．6％,个体数依次占各类茶园总个体数92．0％,93．5％,93．6％和95．0％,捕食性昆虫和捕食螨种数则分别占11．3％,10．0％,9．8％,10．9％,个体数占2．0％,1．1％,2．0％和1．5％,寄生性昆虫种数占9．2％,9．1％,9．3％,和9．3％,个体数占1．8％,1．1％,1．8％和1．3％。蜘蛛种数占24．7％,20．1％,22．4％和19．4％,个体数占3．5％,3．4％,2．1％和1．8％,4类茶园中的优势类群都是鳞翅目,同翅目,翅目,双翅目和蜘蛛目,月平均丰富度（S）和多样性指数H大小,栗－茶间作（S＝74,H＝1．33）,梨－茶间作（S＝49,H’＝1．24）,3行密植（S＝31,H’＝1．03）和单行条植茶园（S＝23,H’＝0．89）,主成分分析揭示了群落稳定性的大小：栗－茶间作＞梨－茶间作＞3行密植＞单行条植茶园。     

不同植茶年限土壤碳氮养分及胞外酶对干旱胁迫的响应

全球气候变暖导致的夏季干旱事件频发影响茶园生态系统生产力,而茶叶是我国南方主要的经济作物,因此研究干旱条件下不同植茶年限茶园土壤养分、生态酶活性及微生物生态变化具有重要意义。选取杭州市余杭区径山茶园3种不同植茶年限(10a、30a和50a)土壤和邻近的荒土为研究对象,研究不同水分(干旱组30%WFPS(water-filled pore space)和对照组55% WFPS)处理前、第7天和第14天的土壤碳氮养分(可溶性有机碳DOC,总有机碳TOC,微生物碳MBC,微生物氮MBN,铵态氮NH_4-N,硝态氮NO_3-N)和胞外酶活性(涉碳胞外酶:β-N萄糖苷酶BG,涉氮胞外酶:N-乙酰氨基葡萄糖苷酶+亮氨酸氨基肽酶NAG+LAP)变化探讨不同水分对不同植茶年限土壤生态系统的影响。结果表明,茶园土壤碳库及涉碳、涉氮胞外酶活性随着植茶年限增加先升高后降低(30a最高);土壤氮库养分随着植茶年限增加而增加。干旱处理增加了土壤TOC、NH_4-N、NO_3-N含量而降低了土壤MBC含量、BG和NAG+LAP活性。处理前后植茶年限30a土壤DOC、MBN、NO_3-N和涉碳、涉氮胞外酶含量最高且其干旱组土壤DOC、TOC、MBC、MBN含量与对照组比变幅相对较小,可推断植茶年限30a左右的土壤微生态环境丰富,对外界环境变化的抵抗力较强。     

外源物质对茶树耐寒及蔗糖代谢关键基因表达的影响

冬春季节低温伤害是影响茶树(Camellia sinensis)生产的重要因素。以茶树盆栽苗为试验材料,通过喷施不同浓度的γ-氨基丁酸(GABA)、绿藻粉和竹醋液溶液,研究低温胁迫下3种外源物质对茶树耐寒能力的影响,并对蔗糖代谢关键基因SPS、SUS4、INV4和INV5表达量及耐寒相关生理指标进行分析,解析外源物质影响茶树耐寒性的生理与分子机制。结果表明,低温胁迫下,用不同浓度GABA、绿藻粉和竹醋液喷施处理茶树盆栽苗叶片,其冻害指数和相对电导率显著低于对照;可溶性糖含量显著高于对照,以10 mmol·L^–1 GABA、0.22 mg·mL^–1绿藻粉及2.5 mg·mL^–1竹醋液处理效果最佳。低温胁迫下,与清水处理相比,分别用10 mmol·L^–1 GABA、0.22 mg·mL^–1绿藻粉或2.5 mg·mL^–1竹醋液处理茶树盆栽苗后,茶树苗丙二醛含量显著降低,抗氧化酶活性显著提高;叶片叶绿素、可溶性糖和脯氨酸含量显著增加,蔗糖含量在处理72小时后分别增加了15.24%、11.39%和5.97%;SPS、SUS4、INV4和INV5基因的表达量显著升高。实验结果表明,GABA、绿藻粉和竹醋液能显著增强茶树的耐寒性。研究结果可为茶树抗寒剂的筛选提供理论依据。     

覆盖与间作对亚热带丘陵茶园地温时空变化的影响

研究了亚热带丘陵茶园连续4年进行稻草覆盖与白三叶草间作对茶园地温时空动态变化的影响.结果表明,茶园地温具有明显的时空动态变化特征和位相滞后现象,与茶树的年生长发育周期各阶段的最适温度非常吻合.稻草覆盖与白三叶草间作改变了土壤热量交换层（地表层）的性质,具有升温时降温和降温时增温、保温的双向动态调控作用,降低了日较差,增强了同一土层温度的稳定性,其调控效果为随着土壤深度增加而降低,13：00>19：00>7：00,降温大于增温和保温,降温幅度随气温的升高而增大,增温和保温随气温的下降而加强,间作白三叶草的降温效果大于稻草覆盖,保温效果则相反.茶园地温时空变化转换点得到调节,显著地降低了有害高温的出现次数,明显地降低了持续高温期的土壤温度,有效地缩短了极限高温时间.     

基于16S rDNA测序对茶园土壤细菌群落多样性的研究

土壤细菌群落组成和多样性,对茶园土壤生态系统健康和肥力可持续性具有的重要理论意义。利用Illumina高通量测序技术测定分析16S rDNA,研究云南景迈山、布朗山和南糯山的现代茶园、古茶园(林)和森林土壤的细菌群落结构与多样性。结果表明:古茶园土壤细菌的丰度和多样性高于现代茶园及森林;研究土壤样本细菌共分属47个菌门、89个目,其中变形菌门、酸杆菌门、放线菌门、厚壁菌门与拟杆菌门是优势类群,它们在森林、现代茶园和古茶园土壤中的相对丰度累计分别达91.86%、82.48%和77.08%;伯克霍尔德氏菌目、根瘤菌目是优势菌群,其平均丰度分别达13.91%和8.17%,黄单胞菌目、红螺菌目、芽孢杆菌目、放线菌目和拟杆菌目等12个目的丰度较高,达2%以上;PCA分析表明:森林、现代茶园和古茶园土壤的细菌群落结构差异明显,除景迈山外,主要优势细菌丰度依次为:古茶园现代茶园森林,古茶园土壤细菌多样性有增强趋势。     

铅在茶树体内的分布及化学形态特征

采用水培试验,结合亚细胞组分分离和化学形态提取技术,研究了茶树品种龙井43和迎霜不同器官的Pb含量,及其在根系亚细胞中的分布和化学结合形态.结果表明： 在Pb胁迫下,两个品种茶树根系的形态特征不同;龙井43新叶中Pb含量随营养液Pb浓度的提高显著增加,而迎霜的变化不显著.两个品种茶树根系亚细胞中Pb的含量分布及结合形态均存在差异,低浓度Pb处理下, 龙井43根亚细胞组分（除可溶物质外）中Pb含量均低于迎霜;而高浓度Pb处理下,龙井43根亚细胞组分（除细胞壁外）中Pb含量均高于迎霜;龙井43根中醋酸(HAc)提取态的Pb含量比例最高,其他化学形态的高低顺序为NaCl提取态>HCl提取态/H₂O提取态>乙醇提取态;而迎霜根中NaCl提取态Pb成分比例最高,其他化学形态的高低顺序为HAc提取态>HCl提取态/H₂O提取态>乙醇提取态.迎霜对Pb毒害的耐受能力强于龙井43.     

Caffeine biosynthesis in young leaves of Camellia sinensis: In vitro studies on N-methyltransferase activity involved in the conversion of xanthosine to caffeine

The aim of this study was to investigate the S -adenosylmethionine dependent N -methyltransferase(s) (NMT) associated with the three methylation steps in the caffeine biosynthesis pathway in tea ( Camellia sinensis L.). NMT activity in cell-free preparations from young leaves was purified by anion-exchange and gel-filtration column chromatography. In both systems, a single zone of NMT activity, with broad substrate specificity was detected. The N-3 position of dimethylxanthine and monomethylxanthines was methylated more readily than N-1 while comparatively little substitution occurred at the N-7 locus. When xanthosine was used as a substrate only the N-7 position was methylated. These results indicate that a single NMT may participate in the conversion of xanthosine to caffeine. The apparent M_r of the NMT, estimated by gel filtration chromatography, was 61 000. The substrate specificity of the NMT is compatible with the operation of a xanthosine → 7-methylxanthosine → 7-methylxanthine → theobromine → caffeine pathway as the main biosynthetic route to caffeine in young tea leaves. The data also indicate that the conversion of 7-methylxanthine → paraxanthine → caffeine may function as one of a number of minor pathways that also contribute to the production of caffeine.     

一种提纯粗茶皂素的简易方法

对粗茶皂素的提取纯化工艺进行了研究。以质量分数为70％的粗茶皂素为原料,经2％NaOH溶解、盐酸酸析、95％乙醇溶解、丙酮沉析工艺得到精制茶皂素。检测结果表明,茶皂素质量分数大于95％,提取率大于80％,这种简便易行的工艺得到的茶皂素可作为开发新型植物灭螺剂的原料。