单子叶植物叶片气孔观察方法改良的研究

通过对传统的植物叶片气孔观察方法的改良,建立了一种观察单子叶植物气孔的有效方法。该方法不仅能够分清上下表皮、准确定位,而且简单易行,具有很高的可靠性和稳定性。实验中采用该法可以准确地获得植物叶片的气孔参数,为植物学及生态学的相关研究提供方法上的参考依据。     

一种禾本科植物鲜叶下表皮制片方法

介绍一种禾本科植物鲜叶下表皮制片的快速方法,该方法也能适用于多数单子叶植物鲜叶和经FAA固定液固定的单子叶植物叶片的气孔观察。该方法制片能有效防止叶表皮脱水、透明后发生卷曲,使保持完整的结构,便于准确的显微观察。具操作简单、材料易得、可靠性和稳定性高等优点。     

青藏高原和内蒙古高原典型草地植物叶片肾型和哑铃型气孔器气孔特征及其与环境的关系

该研究利用植物制片技术,以中国青藏高原和内蒙古高原典型草地常见种或优势种植物的叶片为研究对象,通过比较分析叶片哑铃型气孔器和肾型气孔器的特征及其与环境因子的关系,揭示植物叶片两类气孔器对环境因子的响应策略。结果表明:(1)叶片哑铃型气孔器气孔指标的变异系数小于肾型气孔器。(2)叶片哑铃型气孔器气孔指标与环境气候指标的关系弱于肾型气孔器。(3)叶片哑铃型气孔器气孔特征与环境关系在叶片上下表面之间存在显著差异,而肾型气孔器气孔特征与环境因子的关系在叶片上下表面之间无显著差异。(4)叶片哑铃型气孔器的气孔特征与降水关系密切,而肾型气孔器气孔特征与温度关系密切。(5)同一种气孔器的气孔特征在两个地区(青藏高原和内蒙古高原)间存在显著差异。研究认为,肾型气孔器和哑铃型气孔器的气孔特征及其与环境之间的关系存在差异,在分析气孔特征时有必要将肾形与哑铃形保卫细胞形成的气孔器加以区分,该研究结果有助于进一步理解中国草地植物叶气孔特征对气候变化的响应与适应策略。     

一种用透明胶带粘取叶片表皮观察气孔的方法

用普通塑料透明胶带粘取叶片下表皮观察植物的气孔,比印迹法和撕取下表皮观察气孔的方法具有操作简单、速度快、真实性强的优点,尤其适宜于试管苗等幼嫩材料的气孔变化动态和形态学指标的研究.此法可以防止因保卫细胞失水而导致气孔开张度的变化,能真实地观察植物不同阶段和时期气孔的变化动态.     

新疆12种黄芩属植物叶表皮微形态结构的研究

应用光学显微镜和扫描电镜技术对新疆12种黄芩属植物叶片上的微形态特征进行观察。结果表明:该属植物叶的上表皮细胞形状及垂周壁式样有多种形式;而下表皮细胞形状均为不规则形,垂周壁式样均为深波形,不具分类学意义,但叶片两面分布的气孔器,在不同种间气孔大小、气孔密度、气孔指数、气孔外拱盖内缘等方面都存在着显著差异;其表皮角质层纹饰和表皮毛的微形态也各有不同;大多数植物叶片表面具腺点,其大小、分布及疏密程度也有不同。植物叶表皮上的这些微形态特征,可为探讨本属种间的分类学及亲缘关系提供一定的佐证。     

一份水稻叶片反卷突变体的遗传分析及电镜显微观察

叶片是植物进行光合作用的重要器官。叶片适度卷曲能够提高水稻(Oryza sativa)生长中后期群体基部的光能利用率, 因而有利于水稻产量的提高。该研究首先在水稻T-DNA插入突变体库中发现一份叶片反卷的突变体。遗传分析表明, 该性状受到1对隐性核基因控制。扫描电镜观察结果显示, 突变体成熟叶片上下表皮的气孔发生了畸变; 且叶片上表皮气孔数目增多, 而下表皮气孔数目与野生型基本相同。叶片横切面电镜观察结果表明, 与野生型相比, 突变体叶片的泡状细胞数目和面积在早期(二叶期)就开始增加, 在成熟期更加明显, 这可能是导致叶片反卷的主要原因。     

羊草叶片气孔导度对环境因子的响应模拟

准确定量描述植物气孔对环境的响应是了解植物光合作用机理、预测植物生产力及其大气－植被－土壤系统中水分和热量交换的关键。利用松嫩平原盐碱化草地羊草光合生理特征的野外观测数据,分析了羊草叶片气孔导度对环境因子的反应,结果表明：羊草叶片气孔导度对环境因子变化敏感,尤其对瞬时光合有效辐射（ＰＡＲ）、叶片与空气间的水汽压亏损（ＶＰＤ）和空气温度（Ｔａ）反应十分明显。依据野外实测资料对国际上两类代表性气孔导度     

新教材实验探索二则

在进行叶片结构的观察时．观察气孔是一项不可缺少的项目．因为气孔是植物蒸腾失水的门户,也是气体交换的窗口。正确理解气孔的结构和工作原理是十分必要的。但是通过制作叶片的临时切片观察气孔,很难达到预期的效果。做过各种各样的尝试,甚至用面膜、丙酮的乒乓球溶液也只能观察到气孔的影     

星状雪兔子植物叶的解剖结构对高山环境的适应性

对青藏高原东缘两个不同居群的星状雪兔子植物叶的结构进行了显微观察,观察结果表明:两种不同居群植物的叶片类型均为等面叶,表皮细胞单层,角质层厚,表皮细胞形状为多边形,垂周壁平直或弓形。生于海拔2850m处的星状雪兔子植物,叶片厚度为330.66μm,上表皮气孔密度为106.75,下表皮气孔密度为144.79;海拔2890m处的星状雪兔子植物,叶片厚度为537.07μm,上表皮气孔密度为53.6,下表皮气孔密度为77.30。两种植物叶片类型虽然均为等面叶,但明显表现为两种不同的生态类型,这表明了星状雪兔子植物的叶在无表皮毛保护的情况下对高山环境的适应性并不是单一的。     

外源一氧化氮供体硝普钠对红树植物桐花树气孔运动的调控效应

探索一种用材简单、操作方便、真实性强的观察红树植物桐花树叶片气孔的制片技术,并利用该技术研究不同浓度、不同处理时间的一氧化氮（NO）供体硝普钠（sodium nitroprusside,SNP）对桐花树气孔开闭的影响,探讨了NO调控的气孔运动与外源Ca^2＋的关系以及NO与H202在调节气孔运动过程中的关系。结果表明：在搅碎法、指甲油印迹法、牛皮胶印迹法三种观察气孔方法中,牛皮胶印迹法是观察气孔开度变化的最佳方法。NO能够诱导桐花树气孔快速关闭,且表现出明显的时间效应与浓度效应。NO导致的气孔关闭与Ca^2＋的参与有密切关系,NO与H,q存在明显的协同效应,可以促进气孔关闭。     

Soft‐modeling based spectrofluorimetric study of simultaneous equilibria

A two‐way soft resolution method will fail when applied to a simultaneous equilibria system due to rank deficiency in its concentration profiles. Increasing the dimensionality of measurements from two‐way to three‐way data can be used to overcome this problem. Simultaneous dissociation of two weak acids is considered as a model for simultaneous equilibria. Three‐way data obtained from excitation–emission spectrofluorimetric monitoring of a pH‐metric titration is analyzed using a proper combination of well‐known soft‐modeling methods. Multivariate curve resolution‐alternating least squares is used for calculating the excitation and emission spectral profiles of involved species and rank annihilation factor analysis for obtaining the contribution of each species in measured excitation–emission matrices at different pHs. The results of simulated and real simultaneous acids dissociation equilibria showed that the proposed combined method performs well even in situation when the equilibrium constants are close to each other. The applicability of method for study of an acidic dissociation is also shown. Copyright © 2009 John Wiley & Sons, Ltd.     

黑腹果蝇杂交实验的教学改革

本文介绍关于黑腹果蝇杂交实验的一次教学改革尝试。讨论遗传学实验教学中,如何由常规的“验证性”教学改变为启发式的“发现式”教学,在本实验教学中,学生处于主导地位,自己选择实验组合,提出实验设计方案,独立完成实验内容;教师只是协助学生完成其实验内容。这种教学方法,充分发挥学生学习的主动性,培养学生独立思考和实际操作能力,激发学生的学习兴趣。 Abstract:The paper is concerned about a teaching and learning reform of hybridization experiment of Drosophila melanogaster.In the teaching of genetic experiment,we have adopted a new teaching and learning method which was a discovering way instead of tranditional method .In this way,students themselves selected the combination subject,put forward and carried out the whole experiment scheme.By the reform,we couldd find out that it was helpful not only to improve students' thinking and operating abilities but also to encourage their interests in genetics.     

A new method for multilayered,site-directed immobilization of antibody on polystyrene surface

Polystyrene is a common substrate material for protein adsorption in biosensors and bioassays. Here, we present a new method for multilayered, site-directed immobilization of antibody on polystyrene surface through the linkage of a genetically engineered ligand and the assembly of staphylococcal protein A (SPA) with immunoglobulin G (IgG). In this method, antibodies were stacked on polystyrene surface layer by layer in a potential three-dimensional way and exposed the analyte-binding sites well. Enzyme-linked immunosorbent assay (ELISA) revealed that the new method showed a 32-fold higher detection sensitivity compared with the conventional one. Pull-down assay and Western blot analysis further confirmed that it is different from the ones of monolayer adsorption according to the comparison of adsorption capacity. The differentiated introduction of functional ligands, which is the key of this method, might offer a unique idea as a way to interfere with the dynamic behavior of a protein complex during the process of adsorption.     

用DAPI染色法观察红鲫胚胎发育

以红鲫为研究材料,采用DAPI荧光染料对脱膜的红鲫胚胎进行染色,在荧光体视显微镜下观察红鲫胚胎早期卵裂到囊胚发育的过程.结果表明,该染色方法操作便捷,能更清晰的观察到胚胎发育的外形.值得一提的是:该方法较光学显微镜观察能清晰的观察到核DNA在细胞中的定位,如囊胚期能观察到早期卵裂细胞正进行频繁的有丝分裂等.该方法的获得...     

On the Inference of Functional Circadian Networks Using Granger Causality

Being able to infer one way direct connections in an oscillatory network such as the suprachiastmatic nucleus (SCN) of the mammalian brain using time series data is difficult but crucial to understanding network dynamics. Although techniques have been developed for inferring networks from time series data, there have been no attempts to adapt these techniques to infer directional connections in oscillatory time series, while accurately distinguishing between direct and indirect connections. In this paper an adaptation of Granger Causality is proposed that allows for inference of circadian networks and oscillatory networks in general called Adaptive Frequency Granger Causality (AFGC). Additionally, an extension of this method is proposed to infer networks with large numbers of cells called LASSO AFGC. The method was validated using simulated data from several different networks. For the smaller networks the method was able to identify all one way direct connections without identifying connections that were not present. For larger networks of up to twenty cells the method shows excellent performance in identifying true and false connections; this is quantified by an area-under-the-curve (AUC) 96.88%. We note that this method like other Granger Causality-based methods, is based on the detection of high frequency signals propagating between cell traces. Thus it requires a relatively high sampling rate and a network that can propagate high frequency signals.     

Development of a Novel Biofilm Continuous Culture Method for Simultaneous Assessment of Architecture and Gaseous Metabolite Production

The way that gaseous metabolite production changes along with biofilm architecture development is poorly understood. To address this question, we developed a novel flow reactor biofilm culture method that allows for simultaneous assessment of gaseous metabolite production and architecture visualization. In this report, we establish the utility of this method using denitrification by Pseudomonas aeruginosa biofilms as a model system. Using this method, we were able to collect and analyze gaseous metabolites produced by denitrification and also visualize biofilm architecture in a nondestructive manner. Thus, we propose that this novel method is a powerful tool to investigate potential relationships between biofilm architecture and the gas-producing metabolic activity of biofilms, providing new insights into biofilm ecology.     

Das Leuchten der Pflanzen

The fluorescence of chlorophyll In this study, we show how to gain insight into the dynamics of photosynthesis in a simple way. When a red filter and a special blue lamp are used, the fluorescence of chlorophyll becomes visible to the human eye and common digital cameras. The method not only enables scientists to perceive fluorescence visually in a simple way but is also suitable for teaching. In the future, we hope to obtain new insights, perhaps discovered by enthusiasts equipped with red glasses and blue flashlights on a nightly walk through the forest.