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关键词： 药用植物多糖   生物学功能   应用  

摘要： 本文主要阐述了药用植物多糖的结构及其在抗肿瘤、降血糖、降血脂、免疫调节、抗病毒、抗氧化等多方面的生物学功能,并结合医药、食品、动物养殖业中的实际现状介绍了药用植物多糖的开发利用。

关键词： 园林植物   草履蚧   生物学特性   发生规律   生态学习性  

摘要： 草履蚧隶属昆虫纲硕蚧科,该虫在河南三门峡地区每年1代,多以卵在卵囊内于树下土中越冬,少数以1龄若虫在卵囊中越冬。卵历期250~270天,若虫历期70~80天,蛹历期7~10天,雄成虫历期7~9天,雌成虫历期40~50天。2月下旬至6月下旬均可为害。草履蚧食性杂,主要靠扩散传播,远距离传播则靠苗木调运进行。天敌是控制草履蚧种群繁殖的重要因素,在生产中应注意药物的合理使用,尽量做到充分保护天敌昆虫。

关键词： 水杨酸   有机胺类物质   甜菜蔗糖代谢酶   植物激素   生长调节剂   生物学特性  

摘要： 水杨酸(salicylic ***)作为植物激素，是广泛分布于植物体内的一元酚类物质，被认为是一种激素类物质，对植物生长发育起着重要的调节作用。\n 在有机胺类物质中筛选结果表明:该有机胺可能是一种新的植物生长调节剂。大豆、水稻、甜菜多年多点次的小区试验，为有机胺的安全性、增产性、抗病性、促早熟性和效果稳定性提供了可靠的数据。\n 本文通过酶学分析方法和高效液相色谱法(HPLC)以及土壤养分分析，研究了水杨酸和有机胺分别对甜菜蔗糖代谢酶(SPS，SS，INV)和植物激素(IAA，ABA，GA3)的调节作用，研究了甜菜蔗糖代谢酶和植物激素在甜菜营养生长期间的变化规律。\n 蔗糖合成酶在叶片以分解方向为主，块根中以合成方向为主。叶片中蔗糖磷酸合成酶活性大于蔗糖合成酶活性。在甜菜幼苗期块根中转化酶活性很高，以后显著下降。甜菜营养生长的后期转化酶活性较低。叶片中IAA、GA3和根中ABA的含量在营养生长的前期高而后期低，叶片中ABA和根中IAA的含量营养生长的前期高而后期低。\n 水杨酸和有机胺分别处理都提高了甜菜叶片和根中生长素(IAA)、赤霉素（GA3）的含量、降低了脱落酸的含量，提高叶片和根中的SPS活性，降低蔗糖合成酶的净活力。这有利于甜菜块根生长、光合作用和蔗糖的积累，对提高后期根产量和含糖率有促进作用。\n 有机胺叶喷大豆，株荚数、荚粒数、百粒重均高于清水对照，株荚数增加2.75个、荚粒数增加0.32粒、百粒重增加1.30克，青秕粒减少2.3粒/株，株节数减少1.6节;收获时株高降低1.6-3.5％左右，平均降低2.7％。试验结果看出:该有机胺还可提高大豆的品质和抗逆性。提高作物抗旱能力，具有促早熟作用。增加硝酸还原酶活性和叶绿素含量，提高蔗糖磷酸合成酶、蔗糖合成酶活性。\n 有机胺对水稻幼苗叶喷，提高了水稻叶片中生长素(IAA)、赤霉素(GA3)、脱落酸(ABA)和玉米素(ZR)以及叶绿素的含量，增加了保护酶(超氧化物岐化酶(SOD)过氧化物酶(POD);过氧化氢酶(CAT))的活性，降低了丙二醛(MDA)含量。

关键词： 厚叶木莲   保护生物学   种子生物学   濒危植物  

摘要： 厚叶木莲为国家二级保护植物，但是对其保护生物学还没有深入研究。本文通过种群生态学、传粉生物学、种子生物学等方面的研究工作，探讨了厚叶木莲生长过程各个环节对其濒危的影响并阐述种群日渐濒危的原因。主要结论如下:\n 在南昆山调查样地内有维管束植物239种，隶属于73科136属，以热带成分占有绝对优势。群落中苗仔竹、厚叶木莲为优势种，重要值分别为77.65％和19.28％。本群落以中、小高位芽植物为主，占78.66％。群落成层现象明显，层间植物丰富。种群的年龄结构分析表明，种群已处于衰退模式。\n 厚叶木莲在开放过程中有二次开合和雌雄蕊异熟现象，雌雄蕊有效时期有重合。繁育系统为虫媒异花受精;主要访花昆虫为活动力小的甲虫类，对其吸引物主要是花粉和花瓣。\n 自然授粉结实率较低，人工授粉可以显著提高其结果率和结籽率。种子采集后并不直接萌发，存在休眠现象。经GA3处理后种子可提前萌发，2500mg/L浓度GA3种子萌芽率最高;6-BA、IAA激素处理同清水处理结果相似;GA3处理后的厚叶木莲和深山含笑种子在南昆山厚叶木莲种群生境中出苗率相差不大。\n 据上述研究结果显示，厚叶木莲在原生境中仍具有一定的自然更新能力，应就地保护和迁地保护同步进行，最终实现厚叶木莲的可持续发展。

关键词： 短柄乌头   濒危药用植物   生物学特性   形态变异  

摘要： 短柄乌头为毛茛科乌头属多年生草本植物，其块根中药上又称雪上一枝蒿。主要分布于云南东北部和西北部、四川西南部等省区，云南是其分布中心。短柄乌头性温，味苦、辛，有剧毒，能祛风除湿，消炎镇痛，用于风湿骨痛，跌扑肿痛及牙痛等症，疗效显著。由于短柄乌头的块根含雪上一枝蒿甲素等多种生物碱，民间用于治疗风湿疼痛、跌打损伤、镇痛等。目前短柄乌头用药完全依赖采挖野生资源，由于滥采滥挖，加之森林砍伐，使其生存环境受到破坏。另外受自然气候影响及本身自然繁殖力等因素影响，资源总量急剧下降，已被列为国家珍稀濒危保护植物，载于《中国植物红皮书》中。\n 本论文以云南、四川10个短柄乌头种群为材料，以保护生物学为核心，对短柄乌头开展了生物学特性、种群生态学、解剖生态学、细胞学和繁殖生物学等方面的研究工作。以期对植物物种的生物学研究思路进行探讨，摸索濒危植物保护生物学的研究方法，同时为短柄乌头的保护和可持续利用提供有价值的基础性资料。\n 1、短柄乌头的生物学特性及形态变异研究\n 短柄乌头在自然条件下，种群数量增长以种子行有性繁殖为主。该物种虽然开花、结实正常，但种子有较长的胚后熟过程，加上较低的种子传播效率，实生苗在种群中只占很少比例。成年植株的花芽在七月开始分化，8-9月开花，11月种子成熟，完成生活史，个体生命周期可长达10余年。短柄乌头种群较小，分布在狭小、呈片断化的特殊生境中，生态幅极其狭窄，基本限于在高寒、冷凉的陡坡生长。土壤和群落小气候是限制其分布的主要因素。短柄乌头资源生于海拔3000米以上高寒、紫外线强的高山草甸，野生种群已极为罕见，种质资源的保护刻不容缓。\n 对云南、四川10个种群的20个性状的变异式样进行了研究。对10个种群的形态变异系数进行横向比较后发现:营养性状的变异系数集中分布在6.0％～25.0％之间，平均CV值为14.35。就变异系数来看，总的变异幅度为:中部叶柄长＞上部叶柄长＞株高。生殖性状的变异系数集中分布在5.0％～55.0％之间，平均CV值为21.28，总的变异幅度为:花序长＞小花数＞盔萼宽。生殖性状的平均CV值(21.28)比营养性状平均CV值(14.35)大，表明生殖性状有较大的变异幅，都容易受到外界环境的影响。\n 2、解剖生态学研究\n 短柄乌头的根从纵切面上看，南皮层、韧皮部、形成层以及木质部构成。韧皮部宽广，筛管群不规则散布于韧皮部当中;木质部于形成层内侧，多排列成倒圆锥形或倒八字形、V字形，木质部脊为六原型。短柄乌头植物的叶片由表皮、叶肉和叶脉构成，上下表皮细胞从纵切面上看，排列整齐，呈近长方形扁平状，具较厚的角质层;短柄乌头叶为异面叶，叶肉组织分化明显，栅栏组织与海绵组织界限明显;栅栏组织发达，海绵组织占据的横切面面积较大，有较大细胞空隙，通气组织异常发达。叶肉内气腔大而明显。\n 短柄乌头的气孔器为不定型，即围绕保卫细胞的副卫细胞与表皮细胞无区别，这是毛莨科植物气孔器的典型类型。短柄乌头上、下表皮细胞的表面观以无规则形、垂周壁波状为主。上表皮均无气孔，下表皮具密集的气孔。从解剖特征来看，短柄乌头在根、叶各器官的结构、功能上这些特征都说明了短柄乌头植物生于高海拔高山草甸的生物学特性和对高寒、冷凉生境的生态学要求。\n 3、种群生态学研究\n 以不同生境分布区的短柄乌头为研究对象，分析它的种群生态学及其生态适应特性。对不同海拔生境的短柄乌头群落进行了研究。结果表明:组成短柄乌头群落的植物共28种，隶属23属19科，含有种类数最多的科是菊科。从各样地植物重要值排序知，短柄乌头在这三个代表性群落中不发挥重要作用。总体上说短柄乌头种群的分布格局类型为集群分布，种群聚集尺度多为8m2，当年生植株种群聚集强度高于多年生种群，整个种群分布格局的演化趋势趋向于高聚集强度的集群分布。短柄乌头的集群分布格局的形成，与人类活动、自身的生物学及种群所依存的环境因素有关。因此，在短柄乌头的保护策略上，应当首先保护其自然分布区的生境。\n 4、生殖生物学研究\n 对云南东北部会泽县两个不同海拔地点(绿荫塘，3080 m和小公窑，3480 m)的短柄乌头的传粉生态学进行了比较研究。研究结果表明高海拔居群的单花花期、雄性期持续时间、雌性期持续时间比低海拔长。熊蜂是短柄乌头的主要传粉昆虫，熊蜂取食花蜜为主，在同一个花序上的访问顺序以由下向上为主。低海拔居群的熊蜂访花频率高于高海拔居群，但自然状态下两个居群的结实率并没有显著差异。短柄乌头种子初级散布距离在距植株50-60cm区域种子数目最多，随面积的增加而减少，种子特征使其漂浮能力很强。短柄乌头传粉生物学的研究，为分析短柄乌头的居群扩展受限、濒危机制提供理论依据。\n 5、短柄乌头及近缘种的细胞学研究\n

关键词： bioregenerative life support   flight hardware   gravity sensing   microgravity   orbit   space biology   spaceflight  

摘要： The relationship between fundamental plant biology and space biology was especially synergistic in the era of the Space Shuttle. While all terrestrial organisms are influenced by gravity, the impact of gravity as a tropic stimulus in plants has been a topic of formal study for more than a century. And while plants were parts of early space biology payloads, it was not until the advent of the Space Shuttle that the science of plant space biology enjoyed expansion that truly enabled controlled, fundamental experiments that removed gravity from the equation. The Space Shuttle presented a science platform that provided regular science flights with dedicated plant growth hardware and crew trained in inflight plant manipulations. Part of the impetus for plant biology experiments in space was the realization that plants could be important parts of bioregenerative life support on long missions, recycling water, air, and nutrients for the human crew. However, a large part of the impetus was that the Space Shuttle enabled fundamental plant science essentially in a microgravity environment. Experiments during the Space Shuttle era produced key science insights on biological adaptation to spaceflight and especially plant growth and tropisms. In this review, we present an overview of plant science in the Space Shuttle era with an emphasis on experiments dealing with fundamental plant growth in microgravity. This review discusses general conclusions from the study of plant spaceflight biology enabled by the Space Shuttle by providing historical context and reviews of select experiments that exemplify plant space biology science.

关键词： Evolution   Reproduction   Distyly   Waltheria   Pollination experiments  

摘要： Heterostylous reproductive systems are usually absent on oceanic island. Self-compatibility would, generally, be advantageous for long-distance dispersing species, as it provides reproductive assurance when density of mates is low. The heterostylous reproductive system, often associated with an incompatibility system, may be a constraint on the colonization of remote habitats. It is, therefore, surprising that the distylous shrub Waltheria ovata has colonized all of the Galapagos Islands, situated more than a thousand kilometres off the shore of Ecuador. The present study confirmed the reciprocal herkogamy of W. ovata. A comparison of mainland and the Galapagos Island populations showed a reduction in flower size, including distance between anthers and stigmas and size of anthers on the islands. Some reductions are quite large but not significantly different, mainly due to a high degree of variation among populations on the islands. The pin morph of W. ovata has undergone the most radical adaptive changes in morphology. Pollination experiments of W. ovata disclosed a leak in the incompatibility system on the Galapagos Islands, allowing higher selfing rates as well as intra-morph seed set compared to the mainland populations. This was most pronounced in the thrum morph. The deficient distylous reproductive system may be an adaptation to a pollinator and mate sparse environment on the Galapagos Islands. We conclude that the heterostylous mating system has changed in response to colonization of the Galapagos Islands, giving room for reproductive assurance by seed set after selfings and intra-morph pollinations.

关键词： Potato spindle tuber viroid (PSTVd)   viroid primary and secondary structure   viroid pathogenicity   mutation frequency  

摘要： The complete nucleotide sequences of more than 100 isolates of Potato spindle tuber viroid (PSTVd) collected from locations in the territory of Russia and the former USSR have been determined. These sequences represent 43 individual sequence variants, each containing 1-10 mutations with respect to the "intermediate" or type strain of PSTVd (GenBank Acc. No. V01465). Isolates containing 2-5 mutations were the most common, and 24 sequence variants are described here for the first time. Twenty one isolates contained a mutation found only in Russian and Ukrainian isolates of PSTVd up till now;i.e., replacement of the adenine at position 121 with cytosine (A121C). Many of these isolates contained two mutations-deletion of one of three adenine residues occupying positions 118-120 plus replacement of the adenine at position 121 with either uracil or cytosine (-A120, A121U/C). Both combinations of mutations were phenotypically neutral, i.e. symptom expression in Rutgers tomato was unaffected. Phylogenetic analysis of the sequences of different PSTVd isolates presented in work together with sequences of other naturally-occurring isolates obtained from Internet databases suggesting that known PSTVd isolates may be divided into four groups: (i) a group of isolates from potato and ornamentals where the type strain of PSTVd (PSTVd.018) may be considered to represent the ancestral sequence, (ii) a second group of isolates from potato and ornamentals where PSTVd.123 play the same role as PSTVd.018 for the first group, and iii) a group of potato isolates where PSTVd.125 is a possible ancestral sequence. The fourth and most divergent group of PSTVd isolates differs significantly from these first three groups. The majority of isolates in this group originate from New Zealand and Australia and infect different solanaceous hosts (tomato, pepper, cape gooseberry, potato, and others).

关键词： chloroplasts   Etioplast   Plastid   pot plants   Biological Science Disciplines  

摘要： A crucial role for the ubiquitin–proteasome system in regulating chloroplast plasticity by controlling protein import.

关键词： Computational Biology   Database   Medicinal Plants  

摘要： The change of agricultural practices and other anthropogenic causes has threatened the nature's unique genetic resources in the verge of extinction. In addition to that very little or no sufficient systematic studies have been done to explore and conserve the medicinal and nutritive potentials of these unique genetic resources. However, there are number of commercially available drugs derived from plant sources and also ever increasing demand for the herbal medicine in recent days in the domestic as well as international market. So there is a distinct need for an easy accessible data collection system that provides detailed scientific information of the plants. Keeping these points on mind computational biology techniques are used to construct web-enabled medicinal plant database system for easy retrieval of taxonomic information, photographs, medicinal properties and bioactive compounds of such important plants in the Upper Brahmaputra valley of Assam for scientific users, researchers and home users who interested in medical plants. [ABSTRACT FROM AUTHOR]