遮荫处理对4种草本植物生理生化特性的影响

研究了遮荫处理对少花龙葵、三叶鬼针草、胜红蓟和莶叶片的生理生化特性的影响,结果表明:遮荫处理提高了4种草本植物叶绿素a b含量,叶绿素a/b存在物种差异;4种草本植物叶片最大净光合速率(Pn-max)、光饱和点(LSP)和光补偿点(LCP)均明显下降;少花龙葵叶片MDA和POD含量降低,三叶鬼针草、胜红蓟和莶升高;遮荫处理使少花龙葵、三叶鬼针草和胜红蓟叶片可溶性糖含量增加,可溶性蛋白含量均呈不同程度下降。少花龙葵耐阴性较强,适度遮荫利于少花龙葵生长发育;三叶鬼针草、胜红蓟和莶受到弱光胁迫。     

克隆植物的碳素生理整合及其生态学效应

碳素整合是克隆植物生理整合过程中非常重要的一部分,是克隆植物生存、生长、繁殖的物质基础.克隆植物碳素整合的基本机制具有一定的共同性或相似性,但克隆植物的种类不同、所处生境以及发育阶段不同或所受到的干扰、胁迫的程度不同,其碳素整合的范围、强度、方向、过程等也有所差异.本文对克隆植物碳素生理整合的基本特征、生态效应以及主要的影响因素进行了详细分析,并对迄今有关克隆植物碳素整合的最新研究进展进行了系统总结.同时,对碳素整合的主要研究方法进行了评价与展望,认为在今后研究中,应加强对克隆植物碳素整合的遗传学基础的研究,同时对于碳素整合的生理学、解剖学和生态学机制的研究也亟待深入.     

三江平原典型小叶章种群地上生物量的空间结构分形特征

2005年5月至10月,应用分形几何学的原理和方法对三江平原典型小叶章种群地上生物量与株高的空间结构分形关系进行了研究。结果表明,典型草甸小叶章和沼泽化草甸小叶章的地上生物量与株高存在良好的静态分形关系,其分形维数(D)是对地上生物量在各器官中积累规律的表征;二者地上生物量与株高的对数值线性相关,相关系数分别介于0.579～0.919和0.655～0.914之间(P<0.01,D值介于1.778～3.414和2.238～3.924之间,各时期地上生物量均以株高的幂函数形式积累;二者地上生物量与株高静态分形关系D值的季节动态基本一致,其变化均符合抛物线模型(P<0.05),而局部波动又与地上生物量的变化有关;生长季内,二者地上生物量与株高动态分形关系的D值分别为2.749和2.738,说明地上生物量的积累具有自相似性,符合幂函数增长的分形生长过程。研究还表明,仅用D值来刻画不同植物地上生物量的空间积累与展布存在一定的局限性,它只能用于测度和描述一种植物体生物量的空间积累及其对空间的占据,而一般不能用于植物间相应指标的类比;导致不同植物D值差异的原因可能与植物生长所处生境、外在因素以及模型参数(C)有关。     

Deforestation and Plant Diversity of Madagascar's Littoral Forests

Abstract:  Few studies have attempted to quantify the reduction or document the floristic composition of forests in Madagascar. Thus, we focused specifically on deforestation and plant diversity in Madagascar's eastern littoral community. We used a data set of approximately 13,500 specimen records compiled from both historical and contemporary collections resulting from recent intensive inventory efforts to enumerate total plant species richness and to analyze the degree of endemism within littoral forests. Change in littoral forest cover from original to current extent was estimated using geographical information systems tools, remote sensing data (satellite imagery and low-elevation digital photography), and environmental data layers. Of the original littoral forest only 10.3% remains in the form of small forest parcels, and only 1.5% of these remaining fragments are included within the existing protected-areas network. Additionally, approximately 13% of Madagascar's total native flora has been recorded from these forests that originally occupied <1% of its total land surface, and over 25% of the 1535 plant species known from littoral forests are endemic to this community. Given the ongoing pressure from human settlement along Madagascar's eastern coast, protection of the remaining forest fragments is critical for their survival. Fifteen of the largest intact littoral forest fragments we identified, collectively representing 41.5% of remaining littoral forest, are among priority sites recommended to the government of Madagascar for plant conservation and incorporation into the protected-areas network.     

大坞河流域重金属污染与五节芒光谱效应关系研究

以大坞河流域五节芒（Miscanthus floridulus）可见一近红外光谱以及叶片样本Cu、Zn、Fe元素质量分数监测数据为基础，对研究区内五节芒中重金属质量分数特征、光谱特征及两者的相关性进行了探讨。结果表明：五节芒叶片中3种金属元素的质量分数都较高；从上游到下游，五节芒叶片中Cu质量分数整体呈逐渐降低的趋势，五节芒光谱反射率在可见光区和近红外区均增加，红边“红移”（向长波方向飘移）强度逐渐减小；同时，五节芒叶片中Cu质量分数与五节芒可见光区、近红外区光谱反射率积分值呈负相关性，与红边“红移”强度、土壤中Cu质量分数呈正相关。并由此得出五节芒光谱特征中A1、A2、S等3项指标能够较好反映土壤的Cu污染程度，经进一步深入研究，可以将五节芒作为监测矿区土壤Cu污染的指示植物。     

Streptomyces sp. WJS-825产谷氨酰胺转胺酶发酵条件优化及中试

应用五因子二次正交旋转回归试验设计,建立了微生物谷氨酰胺转胺酶 (TG)发酵生产过程中以酶活力和菌体细胞生长量作为目标函数的数学模型,并以此模型对链霉菌 (Streptomycessp. )WJS-825菌株发酵生产TG的培养条件进行优化,确定了影响TG生产的主要因子及其最适取值为多价胨 2. 1%、可溶性淀粉 1. 5%、初始pH 7. 0及培养温度 30℃.以该优化工艺条件进行了 5L发酵罐小试和 200L发酵规模的中试生产.结果表明,在中试发酵生产中使用以豆饼粉部分替代多价胨的经济性发酵优化培养基,以及发酵过程中在线监控pH、溶氧系数等多项发酵调控参数,并分段控制pH、温度、通气量和搅拌转速以及进行适时的流加补充碳源,该菌株生长繁殖能力强、产酶效果好,TG活性达 3. 2u/mL,而且连续重复的中试发酵生产试验的TG产量均稳定在 3. 2u/mL以上. 图 2表 3参 15     

宁南霉素诱导烟草酸性病程相关蛋白的研究

研究了宁南霉素对烟草酸性病程相关蛋白的诱导表达．结果表明，宁南霉素可系统性地诱导烟草叶片中酸性病程相关蛋白的高效表达．与水杨酸相比，宁南霉素诱导酸性病程相关蛋白的表达水平较高，持续时问较长．此外，在同一品种不同形态叶片烟草植株中，宁南霉素对植物酸性病程相关蛋白的诱导存在差异．图6表3参20     

Concentrations of arsenic and heavy metals in vegetation at two abandoned mine tailings in South Korea

Untreated abandoned mines may result in hazards to ecosystems due to dispersion of various toxic elements such as arsenic (As) and lead (Pb). Phytoremediation is an alternative of remediation for large scale mine dumps. Plant species were sampled from two abandoned gold (Au) mines in South Korea. Plant samples were digested following the guidelines of US EPA Method 3050 (US-EPA, 1996) and analyzed by inductively coupled plasma mass spectrometry (ICP-MS). Concentrations and bioaccumulation factors of plants are reported and out-performing species are summarized. Poplar trees (Populus davidiana) growing on the Myoungbong tailings were suggested to be a potential species for revegetation of large scale Au mine tailings. Arsenic accumulations of bracken ferns (Pteridium aquilinum) sampled from the Duckum tailings were far lower than those of the reported hyperaccumulators, but the possible chronic adverse effects on residents through daily diet are of concern.     

Why do plants ‘talk’?

Summary Plant defence can be induced by herbivory. This is true for both direct and indirect plant defence. Induced direct defence has been the most studied of the two. However, in most cases induced direct defence does not appear to be a water-tight defence option. In contrast, induced indirect defence through the production of herbivore-induced carnivore attractants can be a decisive factor in the extermination of herbivore populations. In this paper the main characteristics of induced attraction of carnivores by plants are reviewed. This includes the similarities and dissimilarities among tritrophic systems. There are two main patterns of induced carnivore attraction. (1) Through the emission of the same bouquet as that emitted by mechanically damaged plants, but in larger quantities and for a longer period of time after damage. (2) Through emission of large amounts of new volatiles that are synthesizedde novo in response to herbivore feeding andnot in response to mechanical wounding.Herbivore populations may be decimated by carnivores. Therefore it should be realized that herbivoreinduced carnivore attractants are essential in an important step in carnivore foraging,i.e. long-distance herbivore location. Once herbivores have started feeding on a plant and direct defence is not effective, induced indirect defence may be decisive for plant survival. Therefore, it is concluded that indirect defence is an essential aspect of induced plant defence directed at herbivorous arthropods.     

多目标优化方法在城市污水厂汇水区污染源总量控制规划中的应用

在城市污水处理厂汇水区实行污染源总量控制,应该避免与城市污水处理厂重复治理.针对这个问题,提出难降解有机物控制的多目标准则指标,建立了多目标优化模型.