Leaf Anatomy (leaf + anatomy)

Distribution by Scientific Domains

Selected Abstracts

Die Blattanatomie eines schnell und eines langsam wachsenden Grases in Abhängigkeit von der Stickstoffversorgung

G. Schulte auf'm Erley
Leaf anatomy of a fast- and a slow-growing grass as dependent on nitrogen supply The grass species Lolium perenne and Festuca rubra, originating from habitats with differing N-availability, differ in their relative growth rate. This is mainly caused by the higher specific leaf area of L. perenne compared to F. rubra. The leaf anatomy of both species was further investigated. The species were raised in growth chambers under high and low N-supply. The higher specific leaf area of L. perenne (27 mm2 mg,1) in relation to F. rubra (14 mm2 mg,1) was mainly caused by a lower leaf density (0.23 vs. 0.33 mg mm,3). The level of N-supply influenced both leaf density and leaf thickness. The leaf volume of L. perenne comprised higher fractions of epidermis and lower fractions of mesophyll and intercellular space compared to F. rubra. However, the discrepancy in leaf density between the species could not be explained by anatomical differences. Under low N-supply, the leaves of both species had higher amounts of vascular bundles and fibre cells and lower amounts of intercellular space, which partly explained the higher density of the leaves. It is concluded, that thinner cell walls and higher amounts of cytoplasm cause the higher specific leaf area of L. perenne. Die Grasarten Lolium perenne und Festuca rubra, die auf Standorten mit unterschiedlicher N-Verfügbarkeit beheimatet sind, unterscheiden sich in ihrer relativen Wachstumsrate. Der Hauptgrund dafür liegt in der höheren spezifischen Blattfläche von L. perenne gegenüber F. rubra. Von beiden Arten wurde die Blattanatomie näher untersucht, nachdem sie in Klimakammern unter einer hohen und einer niedrigen N-Versorgungsstufe angezogen worden waren. Es zeigte sich, daß sich die höhere spezifische Blattfläche von L. perenne (27 mm2 mg,1) gegenüber F. rubra (14 mm2 mg,1) auf eine niedrigere Blattdichte zurückführen ließ (0,23 gegenüber 0,33 mg mm,3). Die Höhe der N-Versorgung beeinflußte sowohl die Blattdichte als auch die Blattdicke. Die Blätter von L. perenne hatten gegenüber denen von F. rubra höhere Volumenanteile an Epidermis und geringere Anteile an Mesophyll und Interzellularen. Die Unterschiede in der Blattdichte zwischen den Spezies ließen sich hierdurch nicht erklären. Unter niedriger N-Versorgung hatten die Blätter beider Arten höhere Anteile an Leit- und Faserbündeln und weniger Interzellularraum, was die höhere Blattdichte unter niedriger N-Versorgung teilweise erklärt. Es wird gefolgert, daß insgesamt dünnere Zellwände und mehr Cytoplasma die höhere spezifische Blattfläche von L. perenne verursachen. [source]

Rhodomyrtophyllum reticulosum (Rossm.) Knobloch & Z. Kva,ek , ein bedeutendes eozänes Florenelement im Tertiär Mitteleuropas

U. Glinka Dipl.-Biol.
Nach kritischer Überprüfung blattepidermaler und blattmorphologischer Merkmalskomplexe an Blättern und Blattresten von RhodomyrtophyllumRüffle & Jähnichen aus dem Weißelster-Becken und seiner Randgebiete in Mitteldeutschland (Raum Halle,Leipzig,Borna,Altenburg,Zeitz,Zwickau und Ostthüringen) wird nachgewiesen, dass es sich bei den Blattresten um Vertreter einer einzigen Art handelt. Die Untersuchungen stützen sich auf 465 Fossilien aus meist kohlig- oder tonig-schluffiger Facies. In einer erweiterten Diagnose wird neben Grundformen mit typischen Charakteristiken die morphologische und blattanatomische Variationsbreite angeführt, die in den natürlichen Grenzen einer Species liegt. Untersuchungen an Blättern weiterer Fundorte in Europa kommen zum gleichen Ergebnis. An Arten von 21 Gattungen rezenter Myrtaceae erfolgen detaillierte Untersuchungen der Blattmorphologie und vor allem der Epidermisstruktur, die markante Ähnlichkeiten zur fossilen Sippe zeigen, was besonders bei Arten der Gattungen SyzygiumGaertn. und Eugenia L. erkennbar ist. Rhodomyrtophyllum reticulosum (Rossm.) Knobloch & Z. Kva,ek , a significant Eocene floral element in the Tertiary of Central Europe The leaf remains of RhodomyrtophyllumRüffle & Jähnichen from the Eocene occurring in the Weißelster Basin in central Germany (area Halle,Leipzig,Borna,Altenburg,Zeitz,Zwickau and Eastern Thuringia) have been proven to belong to a single species. This has been documented by analysing gross morphology and epidermical structure of 465 fossil leaves and leaf fragments from coal sand coal-silt facies. An emended diagnosis characterises besides basic forms with typical gross morphology and leaf anatomy, also extreme specimens within the limits of natural variability of Rhodomyrtophyllumreticulosum. These results correspond with studies from other European localities. Furthermore, detailed analyses of leaf morphology and epidermal structure of 21 recent species of the Myrtaceae are given. These demonstrate analogies of the fossil taxon studied especially among representatives of SyzygiumGaertn. and Eugenia L. [source]

Prediction of species response to atmospheric nitrogen deposition by means of ecological measures and life history traits

Martin Diekmann
Summary 1The main objective of this study was to predict the responses of vascular plant species to atmospheric nitrogen deposition and enhanced soil nitrogen levels. The study was carried out in deciduous forests located in three regions of southern Sweden. The abundance of vascular plants, as well as soil pH and nitrogen mineralization rates, were studied in a total of 661 sample plots. 2We calculated an ecological measure (Ndev value) for all species based on their observed vs. expected nitrification ratios at a given soil pH, and compared its accuracy in predicting abundance changes with results using life history traits. Data from long-term field studies and fertilization experiments were used for validation. 3Ndev values were positively correlated between neighbouring regions. Values for the southernmost region (Skåne) were also positively related to the changes in species frequency observed in large-scale flora surveys and permanent plot studies in that area and with species changes reported from Central Europe. Values from one of two other regions were also consistent. Ndev values from Skåne (but no other region) predicted species responses in short-term fertilization experiments. 4No life history trait was as good a predictor as Ndev, although plant height, leaf anatomy, leaf nitrogen concentration and phenology showed significant correlations. Attributes related to taxonomy, life form, relative growth rate and habitat type showed no agreement with the changes in species abundance. 5We predict that species with the following attribute syndrome will increase in abundance in response to enhanced nitrogen levels: those favoured by a high soil nitrification ratio relative to other species at a given soil pH, tall stature, hydro- to helomorph anatomy, high leaf nitrogen concentration and a late phenological development. [source]

Ants mediate foliar structure and nitrogen acquisition in a tank-bromeliad

Céline Leroy
Summary ,,Aechmea mertensii is a tank-bromeliad that roots on ant-gardens initiated by the ants Camponotus femoratus and Pachycondyla goeldii. Its leaves form compartments acting as phytotelmata that hold rainwater and provide habitats for invertebrates. In this article, we aimed to determine whether the association with either C. femoratus or P. goeldii influenced the vegetative traits of A. mertensii, invertebrate diversity and nutrient assimilation by the leaves. ,,Transmitted light, vegetative traits and phytotelmata contents were compared between the two A. mertensii ant-gardens. ,,Camponotus femoratus colonized partially shaded areas, whereas P. goeldii colonized exposed areas. The bromeliads' rosettes had a large canopy (C. femoratus ant-gardens), or were smaller and amphora shaped (P. goeldii ant-gardens). There were significant differences in leaf anatomy, as shaded leaves were thicker than exposed leaves. The mean volumes of water, fine particulate organic matter and detritus in C. femoratus -associated bromeliads were three to five times higher than in P. goeldii -associated bromeliads. Moreover, the highest invertebrate diversity and leaf ,15N values were found in C. femoratus -associated bromeliads. ,,This study enhances our understanding of the dynamics of biodiversity, and shows how ant,plant interactions can have trophic consequences and thus influence the architecture of the interacting plant via a complex feedback loop. [source]

Ozone-induced reductions in below-ground biomass: an anatomical approach in potato

ABSTRACT Potato plants were grown in open-top chambers under three ozone concentrations during two complete cropping seasons (93 and 77 d in 2004 and 2005, respectively). The effects of chronic exposure to ozone on leaf anatomy, cell ultrastructure and crop yield were studied. Severe cell damage was found, even at ambient ozone levels, mainly affecting the spongy parenchyma and areas near the stomata. Damage to the cell wall caused loss of cell contact, and loss of turgor pressure due to tonoplast disintegration, contributed to cell collapse. Phloem sieve plates were obstructed by callose accumulation, and damaged mesophyll cells increased their starch stores. Tuber yield fell sharply (24,44%), due to the biggest tubers becoming smaller, which affected commercial yield. These anatomical findings show the mechanisms of ozone effect on assimilate partitioning, and thus crop yield decrease, in potato. Further implications of ozone causing reductions in below-ground biomass are also discussed. [source]

Continuous expression in tobacco leaves of a Brassica napus PEND homologue blocks differentiation of plastids and development of palisade cells

Paul Wycliffe
Summary Brassica napus complementary deoxyribonucleic acid (cDNA) clones encoding a DNA-binding protein, BnPEND, were isolated by Southwestern screening. A distinctive feature of the protein was a bZIP-like sequence in the amino-terminal portion, which, after expression in Escherichia coli, bound DNA. BnPEND transcripts were present in B. napus roots and flower buds, and to a lesser extent in stems, flowers and young leaves. Treatment in the dark for 72 h markedly increased the amount of BnPEND transcript in leaves of all ages. Sequence comparison showed that BnPEND was similar to a presumed transcription factor from B. napus, GSBF1, a protein deduced from an Arabidopsis thaliana cDNA (BX825084) and the PEND protein from Pisum sativum, believed to anchor the plastid DNA to the envelope early during plastid development. Homology to expressed sequence tag (EST) sequences from additional species suggested that BnPEND homologues are widespread among the angiosperms. Transient expression of BnPEND fused with green fluorescent protein (GFP) in Nicotiana benthamiana epidermal cells showed that BnPEND is a plastid protein, and that the 15 amino acids at the amino-terminal contain information about plastid targeting. Expression of BnPEND in Nicotiana tabacum from the Cauliflower Mosaic Virus 35S promoter gave stable transformants with different extents of white to light-green areas in the leaves, and even albino plants. In the white areas, but not in adjacent green tissue, the development of palisade cells and chloroplasts was disrupted. Our data demonstrate that the BnPEND protein, when over-expressed at an inappropriate stage, functionally blocks the development of plastids and leads to altered leaf anatomy, possibly by preventing the release of plastid DNA from the envelope. [source]

The microclimate under coloured hailnets affects leaf and fruit temperature, leaf anatomy, vegetative and reproductive growth as well as fruit colouration in apple

A. Solomakhin
The purpose of this study was to investigate supposedly positive biological effects of coloured hailnets on microclimate, including photosynthetically active radiation (PAR), UV-B, air, soil, fruit and leaf temperature as well as humidity, which in turn may affect leaf anatomy, tree growth and fruit quality; apple was chosen as a model crop at Klein-Altendorf near Bonn, Germany; adjacent uncovered trees served as control. Red and green hailnets transmitted 3,6% more red or green light, without alteration of the red:far red (R,666 nm:FR,730 nm) ratio (0.99,1.01:1) and hence without affecting the phytochrome system. The microclimate was changed with a reduction by 12,23% in PAR and, to a larger extent, by 20,28% in UV, viz. shading. Light measurements at a 45° angle, to mimic the fruit or leaf position, showed that PAR was 90,210 µmol m,2 s,1 larger outside on a sunny summer day than under the white or red-white and 150,340 µmol m,2 s,1 larger than under red-black and green-black hailnets. Air temperature and relative humidity under coloured hailnets decreased by ca. 1.3°C and by ca 2% rh (cloudy) to 5% rh (sunny day), respectively, compared with outside; leaf temperature was decreased by up to 3°C and fruit temperature by up to 6°C. Soil temperatures at 5 cm depth were 0.5,1°C colder under red-black and green-black hailnets, but up to 0.9°C warmer under white and red-white hailnets compared with the uncovered control outside. Alternate bearing had a larger impact on vegetative growth in the affected year than the coloured hailnets; annual trunk diameter increments in cv. ,Fuji', i.e. the variety susceptible to alternate bearing, showed a larger variation than cv. ,Pinova' without alternate bearing. Reproductive growth, viz. return bloom and leaf anatomy were impaired by the coloured hailnets. Apple trees under dark hailnets developed thinner leaves with a thinner epidermis and fewer layers of palisade cells. These leaves were 3.5°C (dark hailnets) and 2.5°C (white hailnets) cooler than outside on a sunny day compared with ca. 1.5°C (dark hailnets) and 0.85°C (white hailnets) on a cloudy day. Transpirational cooling of cv. ,Fuji' leaves was 0.3,0.6°C outside and 1.4,1.6°C under the green-black hailnet on sunny days compared to <0.1°C on cloudy days. As a practical application, apple fruit colouration was dependent on light (PAR and UV-B) transmission of the respective hailnet colour. [source]

A new species of Allium (Alliaceae) from Dalmatia, Croatia

Allium croaticum, a new species from the island of Vis in Central Dalmatia (Croatia) is described and illustrated. Its relationships with allied species belonging to the A. stamineum group (Allium section Codonoprasum) are discussed. It is a diploid species (2n = 16), colonizing calcareous screes and flowering in early summer. Its morphology, leaf anatomy, karyology, palynology, ecology and taxonomic position are examined. © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society, 2008, 158, 106,114. [source]

Comparative leaf anatomy of Alpinia Roxb. species (Zingiberaceae) from China

The leaf anatomy of 20 Alpinia species from China was investigated. Results show that there is interspecific variation in the structure of the leaf midrib and petiole which can be used for species identification. Adaxial hypodermis is present in the lamina in all species of subgenus Catimbium and absent from all species of subgenera Dieramalpinia and Aobolocalyx and Alpinia, excepting A. conchigera, A. galanga and A. aquatica, which appear to be closely allied in having subepidermal fibres in midribs and petioles, which are absent from the rest of the species. [source]