Einfluss von Chlorcholinchlorid und Ethrel auf Zellteilung und Zellstreckung bei Primärblättern von Weizenkeimpflanzen

Both chlorcholinchloride and ethrel are used as growth retardants in cereal cultivation. Wheat seedlings were cultivated in nutrient solutions containing 10^-3M CCC, CEPA or 5 × 10^-4M CCC and CEPA, respectively. The epidermis of full-grown primary leaves was analysed. CCC relatively equally decreases the length of leaves and long epidermal cells, whereas CEPA mainly inhibits cell division. Leaf growth is always a little more inhibited than the number of stomata and trichomes is reduced by CCC or CEPA. This results in an increased frequency of stomata and trichomes by about 14 to 16 per cent. This means that retardants can strongly influence the length of leaves and the length or number of long epidermal cells but, due to the mechanism of programmed determination, the frequency of stomata and trichomes is kept constant within relatively narrow limits. Furthermore it can be concluded that long epidermal cells function as pace-makers in the growth of leaves of monocotyledonous plants.      

A new species of Sparganium from the Eocene of Fushun,Liaoning Province

Sparganium fushunense Geng is described as new from the Jijuntun Formation (Middle to Late Eocene) of Fushun region in Liaoning Province, China. The preserved fertile branches bear fruiting heads. A morphological comparison of the fruit heads is made between the specimens studied here with those of the living species and other fossil species. The results show that the new species is distinguishable mainly by the shape of the tepals and the size of the fruits. Sparganium fushunense Geng, sp. nov. Head-bearing axis at least 14.5 cm long, about 1.0 mm wide, with longitudinal striae more or less parallel on its surface. Axes with 4～6 lateral fruit heads, interval between heads 0.5～2.0 cm. Fruiting head sessile, globose, about 5 mm in diameter, made up of tightly packed tepals and fruits radiating from a small receptacle. Tepals narrowly obovate, apically rounded, about 1.8 mm long, 0.2～0.7 mm wide. Fruits elliptic, sessile, with smooth surface, 1.16～1.25 mm long, at apex with a beak 1.5～2.0 mm long. Seed elliptic, long axis 0.48～0.75 mm long, short axis 0.23～0.45 mm long. Seed coat cells irregularly polygonal , 4.1～19 vn in diameter, with smaller ones in both the apical and basalparts,the larger ones in the middle part and a papillate process at the apex.     

叶子花表皮特征的研究及意义

对叶子花（Bougainvillea spectabilis）正常叶和变态叶上气孔密度、气孔指数和保卫细胞大小进行了研究。结果表明：正常叶上表皮的表皮细胞为多边形,垂周壁平直;下表皮的表皮细胞为不规则型,垂周壁浅波状;气孔类型为不规则型。变态叶上表皮没有发现气孔,变态叶下表皮的表皮细胞垂周壁则由浅波形逐渐变为深波形,气孔类型为不规则型和轮列型。随着变态叶的发育,变态叶下表皮的气孔密度降低,气孔指数升高;变态叶保卫细胞的长增大,宽减小。变态叶的平均气孔密度和平均气孔指数明显低于正常叶。正常叶和变态叶的保卫细胞均呈肾形。     

On Cordaites neimengensis sp. nov from Lower Permian of Zhungeerqi,Inner Mongolia, China

The leaf cuticle of Cordaites neimengensis sp. nov was studied by light and scanning electron microscopy. The specimens were collected from kower Permian of Zhungeerqi, Inner Mongolia (Neimenggu), China. Comparing with other species of Cordaites, it was a new species of the genus, based on the structure of its epidermis. Cordaites neimengensis sp. nov (Pis. Ⅰ to Ⅲ; Text-fig.l,B) The specimen comprises two incomplete leaves over 16 cm in length. One is about 1.4 cm wide at the lower part and 0.3 cm wide at the upper part, with nearly 29 veins per cm and 3 to 5 interstitials. The width of the other leaf is about 7.5 cm at the lower part and 8.2 cm at the upper part with 25 veins per cm and 3 to 5 interstitials. Epidermis amphistomatic. Epidermal cells of upper cuticle aligned in longitudinal rows, nearly rectangular in shape, about 33.6 to 86.4 pm x 10.2 to 28. 8 pm in size. Stomatal apparatus consisting of 2 sunken guard cells surrounded by 2 lateral and 2 polar subsidiary cells. Stomata haplocheillic, about 56.2 pm x 45.5 pm in size, usually arranged in short chains, with one polar subsidiary cell (usually 23.1 to 25.4 pm wide, 34.1 to 39.2 pm long in size) shared with 2 consecutive stomata. The polar subsidiary cells round, oblong or rhomboid in shape. The guard cells reniform or bean-shaped, usually 9.7 to 11.6 pm wide, 23.4 to 29.1 pm long in size. Density and index of stomata about 18/mm2 and 3.2%, respectively. Epidermal cells of lower cuticle also nearly rectangular in shape, about 62.4 to 144 pm × 9.6 to 16.8 pm in size. Stomata on the lower cuticle, haplocheillic, 40.8 pm wide and 48 pm long in size, with a pair of sunken guard cells, which is bean-shaped and surrounded by 2 lateral and polar subsidiary cells. Stomata arranging in parallel bands, typically one, sometimes two. As for the latter, a single row of lateral subsidiary cells (9.2 to 14.4 pm wide, 33.6 to 62.4 pm long in size) is shared with 2 parallel rows of stomata and occasionally also in bands with two rows side by side. In view outside, small papillae on the outer periclinal wall as well as the lateral subsidiary cells. In view inside, some folds along the anticlinal wall but flat about the periclinal wall. Nonstomatic bands usually with 1 to 10 rectangular cell rows. Density and index of the stomata about 209/mm2 and 27.2 %, respectively. 1401%-type: 9342; locality: Heidaigou of Zhungeerqi; Inner Mongolia, North China; Age: Lower Pennian (Shanxi Formation).     

Structure and Function in the Grass Ligule: Optical and Electron Microscopy of the Membranous Ligule of Lolium temulentum L.

Aspects of the structure and ultrastructure of the membranousligule of mature leaves of Lolium temulentum L. are described.In transverse section the ligule was lens-shaped and wedge-shapedin longitudinal section, 6 or 7 cells wide near the base and1 or 2 cells wide at the edges. Two uniseriate epidermes encloseda chlorenchymatous mesophyll tissue of varying thicknesses;both epidermes were continuous with the leaf adaxial epidermis.The cells comprising these three issues all appeared like typicalgrass epidermal long cells; elongate papillate cells were presentat the edges. No stomata, trichomes, intercellular spaces orvascular tissue were found in the ligule. A marked polarizationof ultrastructural complexity existed from the large-vacuolateabaxial epidermis to the ‘densely cytoplasmic’ small-vacuolateadaxial epidermis. Cells of the latter tissue contained numerousmitochondria, hypersecretory dictyosomes and abundant strandsof rough endoplasmic reticulum. Fluorescence microscopy providedevidence for the accumulation of a polysaccharide-containingmaterial within the periplasmic space next to the outer tangentialwall of adaxial epidermal cells. The ligule is considered tobe a highly organized and differentiated leaf organ with a pholosyntheticmesophyll and an adaxial epidermis active in the synthesis ofprotein and polysaccharide. Darnel, fluorescence microscopy, ligule, Lolium temulentum L., Poaceae, ultrastructure     

Comparative Anatomy of the Leaves of Cephalotaxus (Cephalotaxaceae)

The internal structure and cuticular characters of the leaves of Cephalotaxus were investigated under light microscope and scanning electron microscope. The materials used belong to 9 species, 2 varieties and 1 cultivar. The leaf characters of C. oliveri Mast. are as follows: stomata are amphicyclic and occasionally monocyclic, the stomatal frequency is 120.6/mm², the hypodermis is present, there are a large number of filiform sclereids and a few brachysclereids and astrosclereids in the mesophyll, the cuticular projections on the lower surfaces are indistinct. This species differs from all the other species of Cephalotaxus, in which stomata are amphicyclic only, the stomatal frequency is 47.3-88.1/mm², hypodermis is absent except in C. harringtonia and C. harringtonia cv. ‘Fastigiata’, foliar astrosclereids, hrachysclereids asd fibriform selereids may be present or entirely absent, there are distinct cuticular projections on the lower surface. Based upon the above-mentioned features, the gross morphology as well as the alkaloids. Cephalotaxus may be divided into two sections, namely: Sect. Cephalotaxus and Sect. Pectinatae. In addition, also discussed are following problems: the classification of some species in Sect. Cephalotaxus, the suggested subdivision of Sect. Cephalotaxus into 4 series, and the systematic position of Cephalotaxaceae.     

中国北方鸢尾属植物叶片解剖结构特征及分类学价值研究

以中国北方生长的鸢尾属9种植物为研究对象,利用光学显微镜对叶表皮细胞形状及大小、气孔大小、气孔分布及气孔密度、气孔指数等叶表皮构造特征进行观察,并探讨了叶表皮特征在鸢尾属内各个亚属、亚组间的分类学价值,结果表明：表皮细胞的形状和大小显示了同亚属或同亚组植物之间较为明显的亲缘关系,在区分鸢尾属下不同亚属或亚组植物上也有一定的分类学价值。气孔密度和气孔指数在鸢尾属内分类学价值不大,但却能很好地反映不同鸢尾属植物与生境之间的密切关系。并从表皮构造特征上证实了野鸢尾与射干有很强的亲缘关系,且近于鸢尾属内的其他植物的结论;此外,通过对鸢尾属植物叶横切解剖结构的观察：从维管束、横切面形状、表皮细胞与角质层、乳突、气孔、气室大小、叶肉细胞的分化这7个较为明显的特征上的相关性和差异性,探讨了由于生境的不同而产生的植物形态结构的差异。     

Clonal analysis of epidermal patterning during maize leaf development

In plants, specialized epidermal cells are arranged in semiordered patterns. In grasses such as maize, stomata and other specialized cell types differentiate in linear patterns within the leaf epidermis. A variety of mechanisms have been proposed to direct patterns of epidermal cell differentiation. One class of models proposes that patterns of cellular differentiation depend on the lineage relationships among epidermal cells. Another class of models proposes that epidermal patterning depends on positional information rather than lineage relationships. In the dicot epidermis, cell lineage is an important factor in the patterning of stomata, but not trichomes. In this study, the role of cell lineage in the linear patterning of stomata and bulliform cells in the maize leaf epidermis is investigated. Clones of epidermal cells in juvenile leaves were marked by excision of dSpm from gl15-m and in adult leaves by excision of Ds2 from bz2-m. These clones were analyzed in relation to patterns of stomata and bulliform cells, testing specific predictions of clonal origin hypotheses for the patterning of these cell types. We found that the great majority of clones analyzed failed to satisfy these predictions. Our results clearly show that lineage does not account for the linear patterning of stomata and bulliform cells, implying that positional information must direct the differentiation patterns of these cell types in maize.     

Rapid low temperature-induced stomatal closure occurs in cold-tolerant Commelina communis leaves but not in cold-sensitive tobacco leaves, via a mechanism that involves apoplastic calcium but not abscisic acid

Commelina communis stomata closed within 1 h of transferring intact plants from 27 degrees C to 7 degrees C, whereas tobacco (Nicotiana rustica) stomata did not until the leaves wilted. Abscisic acid (ABA) did not mediate cold-induced C. communis stomatal closure: At low temperatures, bulk leaf ABA did not increase; ABA did not preferentially accumulate in the epidermis; its flux into detached leaves was lower; its release from isolated epidermis was not greater; and stomata in epidermal strips were less sensitive to exogenous ABA. Stomata of both species in epidermal strips on large volumes of cold KCl failed to close unless calcium was supplied. Therefore, the following cannot be triggers for cold-induced stomatal closure in C. communis: direct effects of temperature on guard or epidermal cells, long-distance signals, and effects of temperature on photosynthesis. Low temperature increased stomatal sensitivity to external CaCl(2) by 50% in C. communis but only by 20% in tobacco. C. communis stomata were 300- to 1,000-fold more sensitive to calcium at low temperature than tobacco stomata, but tobacco epidermis only released 13.6-fold more calcium into bathing solutions than C. communis. Stomata in C. communis epidermis incubated on ever-decreasing volumes of cold calcium-free KCl closed on the lowest volume (0.2 cm(3)) because the epidermal apoplast contained enough calcium to mediate closure if this was not over diluted. We propose that the basis of cold-induced stomatal closure exhibited by intact C. communis leaves is increased apoplastic calcium uptake by guard cells. Such responses do not occur in chill-sensitive tobacco leaves.     

Ecological adaptation characteristics of Populus euphraticaeuphratica and Tamarix ramosissima leaf microstructures in the lower reaches of Tarim River

In order to explore the ecological adaptation in leaf microstructures of Populus euphratica and Tamarix ramosissima in the lower reaches of Tarim River; we used scanning electron microscopy to observe epidermal, cuticular and cross-sectional structures of P. euphratica and T. ramosissima leaves. In addition, their cell submicroscopic structures were studied with transmission electron microscopy. The results revealed that through long-term adaptation to the same environmental conditions, micro-structural of the leaves for the two species exhibit high degree of homoplasy: there is cavity between cuticle and epidermal, and cuticle bulges outwards to form processes mammillaris and epidermal hairs; stomata concaves; fence and vascular tissues are developed; both alisade cells and thin walled cells have chloroplast; vacuoles occupies large volume of the cell space; etc. These features help plants resist drought stress. The salt glands and salt crystallization of T. ramosissima reveals the strong ability of salt stress resistance, but its drought-resistance capacity is weaker than P. euphratica. The specific components of the various shapes of crystal structures in their leaves call for further study.     

Ecological adaptation characteristics of Populus euphraticaeuphratica and Tamarix ramosissima leaf microstructures in the lower reaches of Tarim River

In order to explore the ecological adaptation in leaf microstructures of Populus euphratica and Tamarix ramosissima in the lower reaches of Tarim River; we used scanning electron microscopy to observe epidermal, cuticular and cross-sectional structures of P. euphratica and T. ramosissima leaves. In addition, their cell submicroscopic structures were studied with transmission electron microscopy. The results revealed that through long-term adaptation to the same environmental conditions, micro-structural of the leaves for the two species exhibit high degree of homoplasy: there is cavity between cuticle and epidermal, and cuticle bulges outwards to form processes mammillaris and epidermal hairs; stomata concaves; fence and vascular tissues are developed; both alisade cells and thin walled cells have chloroplast; vacuoles occupies large volume of the cell space; etc. These features help plants resist drought stress. The salt glands and salt crystallization of T. ramosissima reveals the strong ability of salt stress resistance, but its drought-resistance capacity is weaker than P. euphratica. The specific components of the various shapes of crystal structures in their leaves call for further study.     

福建省不同居群轮叶蒲桃叶形态与表皮特征比较

通过对福建省16个不同居群轮叶蒲桃叶片形态特征、叶表皮特征的观察及叶片主要性状的测量,探讨不同居群轮叶蒲桃叶型、叶表皮特征多样性,为属下种间鉴定提供依据。对16个居群轮叶蒲桃叶型多样性进行观察,采用直尺测量叶片主要性状如叶长、叶宽等;采用光学显微镜和扫描电镜对叶表皮特征进行观察。结果表明,16个居群轮叶蒲桃叶片中,闽西居群叶形为阔椭圆形;闽东、闽北、闽南等各地居群叶形为长椭圆形或近带形。不同居群轮叶蒲桃叶片表皮毛、角质层纹饰、气孔器形态与类型等表现一致,但表皮细胞垂周壁式样差异明显,具波状、浅波状、平直、弓形等几种类型,且在上下表皮间存在式样一致或有多元化现象。由此说明,福建省不同居群轮叶蒲桃叶形与表皮细胞垂周壁式样均处于较强烈分化的状态,表皮细胞垂周壁式样不能作为属种间分类的依据。     

新疆2种盐生补血草营养器官的解剖学研究

采用叶片离析法和石蜡切片法,对生长在新疆盐渍环境中的大叶补血草[Limonium gmelinii(Willd.) Kuntze]和耳叶补血草[Limoniumotolepis(Schrenk) Kuntze]的营养器官解剖学特征进行了观察研究.结果显示,2种补血草属典型泌盐植物,茎和叶片表皮上分布有多细胞组成的盐腺;叶表皮细胞排列紧密,其外切向壁增厚,表皮外还被有厚的角质层;上下表皮都有气孔,气孔与表皮细胞平齐,为不等型气孔;其中大叶补血草为异面叶,而耳叶补血草为等面叶.2种补血草茎中都散生有多轮维管束;大叶补血草根中还有大量通气组织等.研究结果表明,2种补血草的解剖结构表现出与其生境相适应的特征.     

Accumulation of malate in guard cells of Vicia faba during stomatal opening

Summary The level of malate in the epidermis from illuminated leaves of Vicia faba was greater than in that from dark-treated leaves. A difference in the malate level was still detected after the epidermis had been treated by rolling so that only the guard cells remained alive. The results suggest that malate may accumulate in guard cells on illumination. In subsequent experiments, stomatal apertures were measured, and potassium as well as malate was analysed in extracts of epidermis. In illuminated leaves, the potassium content of rolled epidermis increased from about 90 to about 335 picoequivalents mm^-2 of epidermis whele malate increased from about zero to about 71 pmoles mm^-2 and the stomata opened; in dark-treated leaves, the potassium content of rolled epidermis decreased slightly, the malate level remained about zero, and the stomata showed very slight further closure. The measured increase in potassium is likely to represent an increase in potassium concentration in the guard cells of about 0.4 Eq l^-1 with stomatal opening; the increase in malate could correspond to 0.23 Eq l^-1 (with respect to potassium) in the guard cells. Thus, malate accumulating in guard cells could balance about half of the potassium taken up by guard cells when stomata open in the light.     

三种国产阴地蕨科植物叶的表皮构造

运用光学显微镜和扫描电镜对三种国产阴地蕨科植物：劲直蕨萁(Botrypus strictus)、小阴地蕨(Botrychium lunaria)和薄叶阴地蕨(Sceptridium daucifolium)〖WTBZ〗叶的成熟表皮构造进行了详细观察和研究。它们具有共同的特征：气孔散生,气孔类型无规则型,气孔长轴方向多与叶脉延伸方向一致。但也存在明显区别,特别是劲直蕨萁与另外二个种的区别更为明显：前者表皮细胞垂周壁直,相邻气孔不接触,保卫细胞平周壁具细条纹。但后二者之间亦有一定区别：薄叶阴地蕨的气孔为下生式,不下陷,而小阴地蕨的气孔为两面气孔型,气孔下陷。本文是国内首次对阴地蕨科叶的表皮构造进行研究,其研究结果表明,表皮构造在阴地蕨科植物的鉴定上具有重要意义,并且在研究阴地蕨科的分类以及起源和演化上也有一定参考价值。     

6种松科植物叶表皮的扫描电镜观察

应用扫描电子显微镜,观察了松科(Pinaceae)3个属6种植物叶表皮特征。金钱松气孔带位下表面,气孔区与非气孔区表皮细胞形态差异很大,气孔细缝状;雪松针叶四面都具气孔线,气孔下陷,孔口光滑,针叶表面具较厚的角质层,表皮细胞形状观察不清;五针松针叶仅两腹面有气孔线,气孔有隆起的圆环围绕,表面角质层呈条纹状排列,形成一种沟槽;黑松、湿地松、马尾松针叶腹背面都有气孔线,气孔呈蜂窝状排列成行,气孔下陷,孔口角质化强烈。结果表明松科3个属植物叶表皮的形态结构及气孔器差异显著,一定程度上证实了3属是自然的分类群。     

不同产地何首乌叶表皮结构的解剖学特征与气候因子的关系

在光学显微镜下观察了不同产地何首乌叶表皮结构特征,应用多元回归方法对不同产地何首乌的叶表皮特征与气候因子的关系进行了分析。观察的叶表皮特征指标有气孔密度、气孔指数、气孔器长、气孔器宽、气孔极区角质加厚、气孔器类型、表皮细胞垂周壁性状及叶表面角质条纹。观察结果:上表皮有少量气孔器分布;在下表皮,气孔器类型为非典型不等细胞型和不规则型,有少量腺鳞分布,气孔器密度每1mm2为241.7(64～573)个,气孔指数为17.1(7.5～26.5)%,气孔器长31.1(20～44)μm,气孔器宽23.1(16～38)μm。随着产地的不同,何首乌叶下表皮结构有明显差异。分析结果显示气孔器、气孔器宽度以及气孔密度均与纬度关系密切,随纬度的升高,气孔器长、气孔器宽呈减小的趋势,气孔密度呈增加的趋势,R2值分别为0.619、0.729、0.772。     

中国29种和泰国1种卷柏科植物的叶形态学研究及其分类学意义

利用光学显微镜和体视显微镜对卷柏科Selaginellaceae中国产29种和泰国产1种植物的叶形态进行了宏观和微观观察。结果表明卷柏科植物在叶形态学方面表现出较高的一致性。(1)叶多为二形, 罕为一形, 无叶柄, 叶二形者侧叶多大于中叶, 外展或斜上, 中叶贴生于腹面茎上, 交互覆瓦状排成4列, 叶一形者则在茎上作螺旋状排列。(2)侧叶与中叶上表皮细胞形态相似, 近等径方形或长方形, 垂周壁平直、弓形或波状; 侧叶与中叶下表皮细胞形态也相似, 长方形或长条形, 垂周壁波状。(3)气孔类型为无规则型或放射型, 气孔多分布于中叶上表皮和侧叶下表皮中脉处。研究发现, 叶外形、叶表皮细胞形态及气孔分布特征等为中国卷柏科植物种间分类提供了重要的参考依据。 研究的有关种类可以依据下面这些特征进行分类: (1)叶为一形叶或二形; (2)叶在枝上着生为螺旋状或成对交互排列; (3)叶表皮细胞垂周壁为平直、弓形、深波状或浅波状; (4)叶上、下表皮细胞同形或异形; (5)气孔为无规则型或放射型; 以及(6)气孔在中叶和侧叶的上、下表皮上的分布等特征。     

Rhododendron longesquamatum var. glabristylum (Ericaceae), a new variety from Sichuan,China

Rhododendron longesquamatum var. glabristylum Y. Y. Geng et Z. L. Zhao , a new variety of the Ericaceae from Sichuan, China, is described and illustrat ed. This variety is different from the typical one by having smaller leaves (5～8×2～3.5 cm) and smalle