Non-Smooth Morphologies of Typical Plant Leaf Surfaces and Their Anti-Adhesion Effects

The micromorphologies of surfaces of several typical plant leaves were investigated by scanning electron microscopy（SEM）. Different non-smooth surface characteristics were described and classified. The hydrophobicity and anti-adhesion of non-smooth leaf surfaces were quantitatively measured. Results show that the morphology of epidermal cells and the morphology and distribution density of epicuticular wax directly affect the hydrophobicity and anti-adhesion. The surface with uniformly distributed convex units shows the best anti-adhesion, and the surface with regularly arranged trellis units displays better anti-adhesion. In contrast, the surface with randomly distributed hair units performs relatively bad anti-adheslon. The hydrophobic models of papilla-ciliary and fold-setal non-smooth surfaces were set up to determine the impacts of geometric parameters on the hydrophobicity. This study may provide an insight into surface machine molding and apparent morphology design for biomimetics engineering.     

4种北极被子植物叶片显微结构和超微结构研究

以采自北极的4种被子植物(高山发草Deschampsia alpina、无茎蝇子草Silene acaulis、仙女木Dryasocto-petala,极柳Salix polaris)为材料,利用光学显微镜和透射电子显微镜,研究了它们叶片显微结构和超微结构.结果显示;(1)高山发草和无茎蝇子草的叶片为等面叶,仙女木和极柳为两面叶,无茎蝇子草和极柳叶肉中含有异细胞;(2)4种植物的细胞超微结构均具有叶绿体紧贴细胞壁分布、叶绿体基质中含有淀粉粒、线粒体紧密地围绕在叶绿体周围的特征,而且高山发草和无茎蝇子草的类囊体出现膨胀,无茎蝇子草和仙女木的细胞基质有大量囊泡,极柳叶绿体内膜附近存在周质网.研究表明,北极植物叶片的结构特点与南极植物和高山植物具有一定的相似之处,北极植物叶片的显微结构和超微结构特征更有利于其适应北极的极端环境.     

高寒草甸不同演替阶段植物叶片功能性状研究

以甘南高寒草甸演替过程中5个阶段的典型群落为研究对象,对围封样地内不同演替阶段群落叶片功能性状进行比较,分析了围封地内各演替阶段群落水平上主要物种叶性状与环境因子的关系。结果显示:(1)此围封地形成了一个从草本到灌木的演替过程。随着演替的进行,Margalef指数显著增加,Shannon-Wiener指数呈先增加后降低的趋势。(2)从演替前期到演替后期,土壤有机碳(SOC)、土壤全氮(STN)、土壤含水量(SWC)逐渐升高,光照度(LI)、土壤温度(ST)逐渐降低,土壤全磷(STP)呈先降低后增加趋势;叶片有机碳(LCC)、全氮(LNC)、含水量(LWC)逐渐升高;比叶面积(SLA)、磷利用效率(PUPE)、稳定碳同位素(δ13C)逐渐下降,叶片全磷(LPC)先降低后升高,而氮利用效率(PUNE)先升高后降低。(3)RDA冗余分析表明,在此围封样地内,演替前期植物群落叶性状主要受到LI和ST的限制作用。而在演替的中后期SWC[WTBZ]是主要影响因子。此研究有助于我们认识高寒草甸生态系统的退化过程所导致的生态环境问题,进而寻求更好的草地恢复和重建方法。     

植物叶片厚度日变化规律数学模型的研究

为了实现对植物生长状态的精确控制,本文对植物的可观测性进行了研究．首先, 运用工业计量的先进方法研制了适合植物叶片精密测量的仪器,用该仪器对二种花卉植物进行了 6个月以上的监测,获得了所监测植物的短周期变化规律,从而证实了植物叶片厚度的“可测量性”．该变化规律的峰值发生在中午,成为研究的重点．对峰值期建立了具有微分形式的数学模型,该模型可为后续的控制研究提供重要的理论依据．     

遮荫对甜瓜叶片光合特性的影响

以适宜不同栽培条件的3个甜瓜品种为材料,研究了遮荫对其光合色素含量、净光合速率及比叶重等叶片特性的影响。结果表明:与正常光照相比,遮光处理能诱使甜瓜叶片叶绿素和类胡萝卜素含量显著提高,叶绿素a/b显著降低。全光照条件下,3个甜瓜品种的净光合速率日变化曲线均呈双峰型,有明显的"光合午休"现象,而在遮荫条件下则呈单峰曲线变化,且光合峰值出现的时间比全光照下推迟;遮光条件下甜瓜叶片气孔导度日变化曲线与其净光合速率日变化类似。3个品种间比叶重在全光照条件下差异不显著,但遮荫显著降低了壮龄叶片的比叶重,且遮荫强度越重,比叶重越小;品种‘黄河蜜3号’壮龄叶的比叶重降幅(31.83%)显著大于‘银帝’(27.22%)和‘玉金香’(26.01%)。可见,遮荫降低了甜瓜叶片的净光合速率和功能叶片的比叶重,植株通过增加自身叶片光合色素含量以增强对环境的适应性,缓解遮荫对其的影响,品种‘银帝’表现出较强的耐弱光性。     

矮丛蓝莓叶片的愈伤组织诱导及植株再生

以矮丛蓝莓'Blomidon'品种的试管苗叶片为外植体,研究不同培养基、激素、转接时间以及转接方式对愈伤组织诱导及植株再生的影响.结果表明:WPM1/2为适宜的培养基;添加0.5 mg·L~(-1) CPPU+1.0 mg·L~(-1) ZT+0.5 mg·L~(-1) TDZ和0.5 mg·L~(-1) CPPU+0.5 mg·L~(-1) ZT+1.0 mg·L~(-1) TDZ诱导愈伤率较高达100%;ZT、CPPU与生长素IAA、IBA的配比诱导愈伤率效果不佳;添加ZT诱导的愈伤组织适合20 d后转接,CPPU诱导的愈伤组织适合50 d后转接;转接方式均以固体培养为宜.矮丛蓝莓'Blomidon'最适宜培养基为WPM1/2+0.5 mg·L~(-1) CPPU+1.0 mg·L~(-1) ZT+0.5 mg·L~(-1) TDZ,其诱导愈伤组织50 d后转接平均分化芽数最多达10.26个.     

Detection of Histone Modifications in Plant Leaves

Chromatin structure is important for the regulation of gene expression in eukaryotes. In this process, chromatin remodeling, DNA methylation, and covalent modifications on the amino-terminal tails of histones H3 and H4 play essential roles^1-2. H3 and H4 histone modifications include methylation of lysine and arginine, acetylation of lysine, and phosphorylation of serine residues^1-2. These modifications are associated either with gene activation, repression, or a primed state of gene that supports more rapid and robust activation of expression after perception of appropriate signals (microbe-associated molecular patterns, light, hormones, etc.)^3-7. Here, we present a method for the reliable and sensitive detection of specific chromatin modifications on selected plant genes. The technique is based on the crosslinking of (modified) histones and DNA with formaldehyde^8,9, extraction and sonication of chromatin, chromatin immunoprecipitation (ChIP) with modification-specific antibodies^9,10, de-crosslinking of histone-DNA complexes, and gene-specific real-time quantitative PCR. The approach has proven useful for detecting specific histone modifications associated with C₄ photosynthesis in maize^5,11 and systemic immunity in Arabidopsis³.     

枣树离体叶片不定芽再生体系建立的研究

建立了木枣无菌试管苗快繁体系,以无菌苗叶片为外植体,对影响离体叶片不定芽直接再生的因素进行了研究.试验结果表明,TDZ比BA能更有效地诱导叶片不定芽的再生;褐化是抑制不定芽再生频率提高的关键因子,培养基中添加PVP、V c及改变生长素的种类和浓度均不能促进不定芽再生;添加A gNO3能够减轻褐化并可以大幅度提高再生频率,同时培养初期经过3周避光培养更有利于提高再生效率.因此,以附加2.0 m g/L TDZ和0.2 m g/L IBA的M S培养基,并添加5.0 m g/L A gNO3,可以高效诱导木枣离体叶片不定芽再生,再生频率最高达98.3%.不定芽在附加0.2 m g/L IBA和0.5 m g/L GA3的M S培养基上进行继代伸长培养,当不定芽长至3 cm时,转接至附加0.4 m g/L IBA的1/2 M S培养基上可以良好地诱导生根.     

The Novel Mechanical Property of Tongue of a Woodpecker

Biomaterials such as bone,teeth,nacre and silk are known to have superior mechanical properties due to their specificnanocomposite structures.Here we report that the woodpecker’s tongue exhibits a novel strength and flexibility due to its specialcomposite micro/nanostructure.The tongue consists of a flexible cartilage-and-bone skeleton covered with a thin layer tissue ofhigh strength and elasticity.At the interface between the cartilage-and-bone skeleton and the tissue layer,there is a hierarchicalfiber-typed connection.It is this special design of the tongue that makes the woodpeckers efficient in catching the insects insidetrees.The special micro/nanostructures of the woodpecker’s tongue show us a potential method to enhance the interfacialconnection between soft and hard material layers for bio-inspired composite system designs.     

Thermoinduction of Chlorophyll Fluorescence and the Age-Related Condition of Higher Plant Leaves

The age-related changes in the temperature dependence curves (TDC) of chlorophyll fluorescence were studied in leaf segments of wheat (Triticum aestivumL.), tomato (Lycopersicum esculentumMill.), and cucumber (Cucumis sativumL.) plants grown under controlled photoculture conditions. Three major TDC patterns of chlorophyll fluorescence were identified within the temperature range of 25–70°C, with each of the patterns corresponding to a certain phase of leaf development. The transition from one type of thermogram to another was a gradual and ordered process. The magnitude of the low-temperature TDC peak increased until leaves completely expanded and declined with leaf senescence. In the course of leaf senescence, the thermograms exhibited an additional shoulder, which further changed into a peak at 55–65°C with increasing magnitude. Our data provide the basis for assessing leaf age from the type of chlorophyll fluorescence thermogram and the changes in the particular indices characteristic of TDC of chlorophyll fluorescence.     

不同功能型植物叶氮含量与光合特性的关系研究

在山西南部的霍山七里峪林场,确定乔木、灌木和草本物种共26个,用Li-3000A叶面积测定仪测量了叶面积的大小、用Li-6400便携式光合作用测定系统测定了叶光饱和速率（A_area）,计算了比叶重（LMA）、单位重量的光饱和光合速率（A_mass）、单位面积叶氮含量(Narea)、单位重量叶氮含量(N_mass)及光合氮利用效率(PNUE),研究了它们之间的不同和相互作用关系。结果表明：不同功能型植物的N_mass、A_area、A_mass、N_area和PNUE差异显著(p<0.05),植物叶片氮含量与植物光合生理特性具有显著相关关系,N_mass与A_area、A_mass和PNUE呈线性显著的正相关(p<0.05);N_area与A_area、A_mass、PNUE之间呈极显著的负相关(p<0.01)。     

A Latitudinal Cline in Leaf Inclination of Dryas octopetala and Implications for Maximization of Whole Plant Photosynthesis

Mean leaf inclination of the arctic and alpine shrub Dryas octopetala is a function of latitude and this functional relationship is consistent with a model that maximizes photosynthesis of the total plant canopy.     

稀有植物香果树叶解剖结构的研究

通过石蜡切片法制片,光学显微镜观察,Motic显微摄像,研究了香果树（Emmenopterys henryi Oliv.）的叶形态解剖结构。结果表明,香果树叶为典型异面叶;表皮由一层紧密的形状不规则的表皮细胞组成,细胞外壁角质膜较薄;气孔类型为平列型,仅分布于下表皮;下表皮上零星分布着多细胞表皮毛;叶肉组织发达,栅栏组织由1~2层排列整齐的圆柱形细胞构成;海绵组织枝状分布,排列极为疏松,细胞间隙大;叶脉主脉发达;上述特征反映出植物结构与环境的统一性。     

植物叶片蛋白质双向电泳技术的改进与优化

通过对传统的双向电泳方法进行改进与优化,得到了一种适合于分析植物叶片蛋白质的双向电泳新方法。用改进后的方法对水稻不同时期成熟叶片蛋白质进行双向电泳分离,结果显示其稳定性和重复性好,分辨率较高,经考马斯亮蓝染色后可分辨出３００多个蛋白质（肽）点。它们的等电点和分子量主要分布于ｐ＊４．１－８．２和１０－１００ｋＤａ之间,本还就实验过程中出现的一些技术问题进行了讨论。     

Plant Regeneration from Wheat Leaf Explants

The factors affecting the callus formation and regeneration capacity of leaf explants of four genotypes of the genus Triticum, viz. T. aestivum, cvs. Taezhnaya and Chinese Spring; T. durum, cv. Kollektivnaya; and T. persicum, were investigated. The process of callus formation did not depend on the explant genotype. Apical leaf segments were characterized by the lowest capacity of callus formation. In contrast, the rate of plant regeneration was correlated with the genotype and the explant developmental stage. The highest number of regenerants was obtained from a basal segment of three-day-old seedlings ofT. aestivum, cv. Taezhnaya. The yield of plants from one explant was doubled due to the use of maltose in the regeneration medium. The prospects of using leaf segments as the explants for the genetic transformation of wheat plants are discussed.     

明日叶叶片的丛生芽诱导和植株高频再生

明日叶（Angelicake＆keiKoidzumi）是伞形花科当归属植物,具有很高的药用价值。为解决生产上短时间快速获得大量明日叶种苗的相关技术,以明日叶叶片为外植体进行组织培养实验,直接诱导产生丛生芽并且得到再生植株,建立了明日叶叶片离体再生快速繁殖体系。结果表明,诱导丛生芽分化的最适培养基是Ms＋1．0mg·L-1,2,4-D＋0．2mg·L～6-BA,诱导率可高达100％;诱导生根的最适培养基是Ms＋1．0mg·L-1NAA,诱导率可达90％,将生长良好的再生植株进行移栽,存活率可达86％。     

广佛地区典型湿地类型植物多样性与土壤因子的关系

为了解土壤影响湿地植物多样性的主要因子,在广佛地区9大湿地类型选取18个样地作为研究对象,通过样方调查以及内业试验获得湿地群落物种组成分布、植物多样性、土壤状况等数据,运用方差分析、典范冗余分析(RDA)、典范对应分析(CCA)对群落分布、植物多样性与土壤因子之间的相关性进行分析。经实地调查,统计出湿地植物312种,隶属90科198属,以禾本科(Gramineae)、莎草科(Cyperaceae)、菊科(Compositae)等为优势科。草本植物占绝对优势,占79.17%。主成分评价结果表明, 近海及海岸湿地土壤养分水平较高。RDA排序分析结果表明土壤因子对植物多样性影响较大的指标是土壤有机质、全氮、全磷、全钾、碱解氮;CCA排序结果表明土壤环境因子对湿地草本植物群落分布主要影响因子为pH、速效钾、有效磷。各研究结果表明,湿地生态系统比陆地生态系统更为复杂和脆弱,植物群落与土壤环境因子之间的关系也更为复杂,湿地植被的分布格局、群落多样性、群落结构和土壤条件及其相互关系受到人为干扰的类型和强度影响更加明显。     

光周期对泡桐叶片体外植株再生影响研究

以毛泡桐、兰考泡桐和白花泡桐叶片为外植体,在其体外器官直接再生的最适MS和1/2MS培养基上,研究了不同光周期对泡桐叶片体外植株再生的影响.结果表明,光照时间为24 h的光周期可促进泡桐叶片芽的诱导,但不同种泡桐叶片芽诱导率达到最大所需时间存在一定差异.对幼芽根诱导来说,不同光周期对3种泡桐幼芽生根的作用存在差异.当幼芽诱导根时间为7 d时,光照时间长于或短于16 h的光周期都会抑制毛泡桐和兰考泡桐幼芽根的诱导,并且这些不适宜的光周期对白花泡桐和毛泡桐幼芽生根的抑制作用大于兰考泡桐.     

中国4种水韭植物叶片分类学特征的比较观察

我国共有5种水韭,全部被列为国家一级保护,均属极度濒危级（CR）野生植物。就营养器官而言,因水韭根、茎的简化,叶片特征成为最重要的分类学依据。本文针对形态特征相近的中华水韭、云贵水韭、台湾水韭和东方水韭,用显微镜观察了叶片发育的形态特征。结果表明：不同种水韭叶片在旋转角度、气孔分布等方面存在差异,而气孔器的种间一致性较高;同种水韭叶片在不同发育时期,其近远轴面的气孔指数、气孔分布及叶凸指数均有稳定的分类价值。本文检索讨论了我国4种水韭的分类学关系,并发现了叶表皮都存在异形条状细胞。