scholarly journals Structures of Heracleum sosnovskii Manden. stem and leaves releasing photodermatosis-causing substances

2012 ◽  
Vol 67 (4) ◽  
pp. 25-32 ◽  
Author(s):  
Elżbieta Weryszko-Chmielewska ◽  
Mirosława Chwil
Keyword(s):  
Fluorescence Microscopy ◽  
Human Skin ◽  
Leaf Surface ◽  
Epidermal Cells ◽  
Secretory Structures ◽  
Intense Fluorescence ◽  
Abaxial Leaf Surface ◽  
Stems And Leaves

In its stems and leaves, <em>Heracleum sosnovskii</em> Manden. contains furanocoumarins, which exert a phototoxic effect on humans. The aim of the investigations was to describe the external secretory structures of the epidermis and internal secretory tissues in organs responsible for emission of secretion that is toxic to human skin. The study was conducted using light and fluorescence microscopy. On the stems and leaves, various types of secretory trichomes with dispersed or deposited secretion were found. The trichomes were most abundant on the abaxial leaf surface. Epidermal cells and the secretion present on the trichomes exhibited intense fluorescence, which may indicate the presence of furanocoumarins in the tissue and trichome secretions.

scholarly journals Leaf surface of two understorey shrubs Rudgea Decipiens Müll. Arg. and Rudgea macrophylla Benth. (Rubiaceae)

Rodriguésia ◽  
1993 ◽  
Vol 45-49 (71-75) ◽  
pp. 7-13 ◽  
Author(s):  
André Mantovani ◽  
Ricardo Cardoso Vieira
Keyword(s):  
Environmental Factors ◽  
Atlantic Forest ◽  
Leaf Surface ◽  
Epidermal Cells ◽  
Surface Features ◽  
Unusual Pattern ◽  
Abaxial Leaf Surface ◽  
Surface Correlations

ABSTRACT MICROMORPHOLOGICAL CHARACTERISTICS OF LEAF SURFACE OF TWO SPECIES OF RUDGEA ARE PRESENTED. THE STUDY WAS BASED ON MATERIAL FROM THE UNDERSTOREY OF ATLANTIC FOREST. SPECIAL ATTENTION IS PAID TO THE OCCURENCE OF SMOOTH AND STRIATED CUTICLE, TO PARACYTIC STOMATA,(SOME OF WHICH EXIHBIT AN UNUSUAL PATTERN IN THE ARRANGEMENT OF THE SURROUNDING EPIDERMAL CELLS) AND TO PAPILLAE, WHICH ARE IRREGULARLY DISTRIBUTED ON THE ABAXIAL LEAF SURFACE. CORRELATIONS BETWEEN THE LEAF SURFACE FEATURES AND ENVIRONMENTAL FACTORS ARE DISCUSSED.

Defence reactions of Hordeum chilense accessions to three formae speciales of cereal powdery mildew fungi

2000 ◽  
Vol 78 (12) ◽  
pp. 1561-1570 ◽  
Author(s):  
D Rubiales ◽  
T LW Carver
Keyword(s):  
Powdery Mildew ◽  
Leaf Surface ◽  
Penetration Resistance ◽  
Blumeria Graminis ◽  
Epidermal Cells ◽  
Hordeum Chilense ◽  
Adult Plant ◽  
Formae Speciales ◽  
Abaxial Leaf Surface ◽  
Stomatal Complexes

The histology of resistance to infection by Blumeria graminis DC Speer f.sp. hordei, Blumeria graminis f.sp. tritici, and Blumeria graminis f.sp. avenae was studied in 15 accession lines of Hordeum chilense. All were highly resistant to all formae speciales. There were small differences in spore germination rates and the morphological normality of germlings formed on the different lines. Relatively large differences between accessions were detected in terms of penetration resistance and the frequency with which attacked epidermal cells died. Greater penetration resistance was expressed by epidermal cells of the seventh-formed leaves than by earlier leaves, indicating that penetration resistance is a component of adult plant resistance in H. chilense. Epidermal cells overlying vascular tissues (long epidermal cells) were more resistant to penetration than cells adjacent or close to stomatal complexes. In a limited examination involving two accession lines, epidermal cells on the abaxial leaf surface of one line were more penetration resistant than those on the adaxial surface; the other line was highly resistant on both surfaces. However, in the few cases where long cells and abaxial cells were penetrated, the frequency of associated cell death was lower than in short cells or on the adaxial leaf surface. This is consistent with the macroscopic observation that the few colonies formed on H. chilense were often close to the mid-rib and more frequent on the abaxial leaf surface. The data support the view that H. chilense offers a valuable source of powdery mildew resistance for cultivated cereals.Key words: Blumeria graminis, Erysiphe graminis, powdery mildew, disease resistance, histology, Hordeum chilense.

Picking sides: feeding on the abaxial leaf surface is costly for caterpillars

Planta ◽  
2021 ◽  
Vol 253 (4) ◽  
Author(s):  
Sakshi Watts ◽  
Rupesh Kariyat
Keyword(s):  
Leaf Surface ◽  
Abaxial Leaf Surface

Thy-1+ Epidermal Cells Are Not Demonstrable in Rat and Human Skin

1986 ◽  
Vol 87 (1) ◽  
pp. 30-32 ◽  
Author(s):  
Rhonna L. Cohen ◽  
John M. Crawford ◽  
Donald A. Chambers
Keyword(s):  
Human Skin ◽  
Epidermal Cells

Cryptic speciation in the herbaceous bamboo genus Piresia (Poaceae, Olyreae)

2019 ◽  
Author(s):  
Maria L Silveira de Carvalho ◽  
Izabela S D de Jesus ◽  
Rilquer M da Silva ◽  
Kelly R B Leite ◽  
Alessandra S Schnadelbach ◽  
...  
Keyword(s):  
New Species ◽  
Atlantic Forest ◽  
Leaf Surface ◽  
Conservation Status ◽  
Integrative Approach ◽  
Niche Modelling ◽  
The North ◽  
Abaxial Leaf Surface ◽  
Herbaceous Bamboos ◽  
North Eastern

Abstract Piresia, a small genus of herbaceous bamboos, has a geographical disjunction between the Caribbean and northern/western South America and the north-eastern Atlantic Forest in Brazil. Piresia leptophylla is reported from western Amazonia (WA) and the north-eastern Atlantic Forest (NAF), but its occurrence in western Amazonia is questionable. Using an integrative approach, we combined traditional morphological analysis, anatomy and niche modelling. The results revealed few macromorphological differences between WA and NAF specimens (only plant height, leaf length, lodicule dimensions, shape and position), contrasting with consistent differences in leaf anatomy (macrohairs and cruciform silica bodies in the costal zone of the adaxial/abaxial leaf surfaces, crenate silica bodies on the abaxial leaf surface, lack of panicoid hairs on the abaxial leaf surface, bicellular microhairs and lobed papillae over the abaxial leaf surface, and sparse but elongated fusoid cells in the mesophyll of WA specimens) and in niche patterns. The anatomical/micromorphological characters suggest environmental adaptations to the Amazonian and ‘restinga’ forests, respectively. We therefore propose the segregation of the WA populations into a new species, Piresia tenella sp. nov. We provide a formal description, photographs, a line illustration, a distribution map and discussion of the conservation status for the new species.

scholarly journals Adjuvant Effects on Imazethapyr, 2,4-D and Picloram Absorption by Leafy Spurge (Euphorbia esula)

Weed Science ◽  
1996 ◽  
Vol 44 (3) ◽  
pp. 469-475 ◽  
Author(s):  
W. Mack Thompson ◽  
Scott J. Nissen ◽  
Robert A. Masters
Keyword(s):  
Ammonium Nitrate ◽  
Ammonium Sulfate ◽  
Seed Oil ◽  
Leaf Surface ◽  
Leafy Spurge ◽  
Cuticular Waxes ◽  
Adaxial Leaf Surface ◽  
Abaxial Leaf Surface ◽  
Urea Ammonium Nitrate ◽  
Adjuvant Effects

Laboratory experiments were conducted to identify adjuvants that improve absorption of imazethapyr, 2,4-D amine, and picloram by leafy spurge. Adjuvants (0.25% v/v) included crop oil concentrate (COC), methylated seed oil (MSO), nonionic surfactant (NIS), organosilicones (Silwet L-77®, Sylgard® 309, Silwet® 408), 3:1 mixtures of acetylinic diol ethoxylates (ADE40, ADE65, ADE85) with Silwet L-77, ammonium sulfate (2.5 kg ha−1), and 28% urea ammonium nitrate (UAN, 2.5% v/v). Adjuvants were combined with14C-herbicide and commercially formulated herbicide product. Leaves were harvested 2 DAT, rinsed with 10% aqueous methanol to remove surface deposits of herbicide, and dipped in 9:1 hexane:acetone to solubilize cuticular waxes. Imazethapyr absorption increased by 38 to 68% when UAN was combined with COC, NIS, or MSO. Total absorption of imazethapyr plus COC, MSO, or NIS exceeded 86% 2 DAT when UAN was added. Urea ammonium nitrate reduced the amount of imazethapyr associated with the cuticular wax by 2.0%. Imazethapyr absorption was similar on both the abaxial and adaxial leaf surface when UAN was not added; however, 12% more imazethapyr was absorbed from the abaxial leaf surface than from the adaxial leaf surface when UAN was combined with Sylgard 309. Uptake of 2,4-D ranged from 54 to 78% and was greatest with Silwet 408 and 3:1 mixture of ADE40: Silwet L-77. Picloram absorption ranged from 3 to 19%. Buffering picloram treatment solutions to pH 7 and including 2.5 kg ha-1ammonium sulfate increased picloram absorption to 37%.

New and noteworthy Melastomataceae from the Yanachaga-Chemillén National Park and surrounding areas in Oxapampa, Pasco, Peru

Phytotaxa ◽  
2018 ◽  
Vol 374 (3) ◽  
pp. 185 ◽  
Author(s):  
FABIÁN A. MICHELANGELI ◽  
RENATO GOLDENBERG
Keyword(s):  
National Park ◽  
Leaf Surface ◽  
Nodal Line ◽  
Abaxial Surface ◽  
North East ◽  
The North ◽  
The Andes ◽  
Abaxial Leaf Surface ◽  
Surrounding Areas ◽  
Sclerophyllous Forests

We describe six new species of Melastomataceae from the Yanachaga-Chemillén National Park and surrounding areas from the Department of Pasco, Province of Oxapampa in Central Peru. Macrocentrum andinum is the first species of the genus described from the Andes, found along creeks at 400–500 m elev. and characterized by its anysophyllous leaves, pubescent stems and four-merous flowers. Meriania rubriflora is found in forests above 2200 m elev. and it is characterized by stem nodes with stipular flaps, leaves with an acute base and four merous, deep red flowers. Miconia palcazuana is found along rivers and streams at 300–400 m on the eastern flank of the park, and it can be distinguished by its flowers with pink anthers with glands on the connective and narrowly oblanceolate to elliptic-lanceolate leaves. Miconia yanachagaensis grows in the dwarf-sclerophyllous forests at the top of ridges and grasslands over 2800 m elev. and it is characterized by its long dendritic-pedicellate trichomes on the abaxial leaf surface, the stems flattened to terete and the presence of a conspicuous annular nodal line. Triolena rojasae is found growing on rocks along the Palcazú River and its tributaries, and it is characterized by its lanceolate-crenate leaves. Triolena vasquezii grows on the northern end of the Huancabamba canyon and the North East portion of the park and can be distinguished by its pustulate leaves with purple abaxial surface and anthers with two ventral appendages. We also present the first report of the genus Wurdastom for Peru.

scholarly journals Effect of Fungicide Mobility and Application Timing on the Management of Grape Powdery Mildew

Plant Disease ◽  
2020 ◽  
Vol 104 (4) ◽  
pp. 1167-1174 ◽  
Author(s):  
Brent Warneke ◽  
Lindsey D. Thiessen ◽  
Walter F. Mahaffee
Keyword(s):  
Powdery Mildew ◽  
Leaf Surface ◽  
Quality Standards ◽  
Pinot Noir ◽  
Abaxial Surface ◽  
Phenological Stages ◽  
Application Timing ◽  
Abaxial Leaf Surface ◽  
Detached Leaves ◽  
Grape Powdery Mildew

Grape powdery mildew (GPM) fungicide programs consist of 5 to 15 applications, depending on region or market, in an attempt to achieve the high fruit quality standards demanded by the market. Understanding how fungicides redistribute and targeting redistributing fungicide to critical crop phenological stages could improve fungicide protection of grape clusters. This study evaluated fungicide redistribution in grapevines from major fungicide groups labeled for GPM control. Translaminar and xylem redistribution was examined by placing fungicide-impregnated filter disks on the adaxial or abaxial leaf surface of detached leaves for 10 min and then incubating for 48 h before inoculating the abaxial surface with conidia. Vapor redistribution used Teflon disks sprayed with fungicides and placed on the abaxial leaf surface of detached leaves 48 h before inoculation. Disease development was rated 10 days later. Translaminar movement through calyptra was tested using flowering potted vines. All fungicides tested redistributed through at least one mechanism. Fungicide timing at critical phenological stages (early, mid, and late bloom) was assessed in small plots of cultivar Pinot noir vines. The application of trifloxystrobin, quinoxyfen, or fluopyram at different bloom stages showed that applications initiated at end of bloom resulted in the lowest berry infection probabilities of 0.073, 0.097, and 0.020, respectively. The results of this study suggest that integrating two carefully timed applications of redistributing fungicides initiated at end of bloom into a fungicide program may be an effective strategy for wine grape growers in western Oregon to produce fruit with low GPM infection.

scholarly journals Foliar epidermis morphology in Quercus (subgenus Quercus, section Quercus) in Iran

2012 ◽  
Vol 71 (1) ◽  
pp. 95-113 ◽  
Author(s):  
Parisa Panahi ◽  
Ziba Jamzad ◽  
Mohammad Pourmajidian ◽  
Asghar Fallah ◽  
Mehdi Pourhashemi
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Statistical Analysis ◽  
Leaf Surface ◽  
Epicuticular Waxes ◽  
Abaxial Leaf Surface ◽  
Trichome Types ◽  
Foliar Morphology ◽  
Scanning Electron ◽  
Foliar Epidermis

Foliar epidermis morphology inQuercus(subgenusQuercus, sectionQuercus) in IranThe foliar morphology of trichomes, epicuticular waxes and stomata inQuercus cedrorum, Q. infectoriasubsp.boissieri, Q. komarovii, Q. longipes, Q. macranthera, Q. petraeasubsp.ibericaandQ. robursubsp.pedunculiflorawere studied by scanning electron microscopy. The trichomes are mainly present on abaxial leaf surface in most species, but rarely they appear on adaxial surface. Five trichome types are identified as simple uniseriate, bulbous, solitary, fasciculate and stellate. The stomata of all studied species are of the anomocytic type, raised on the epidermis. The stomata rim may or may not be covered with epicuticular. The epicuticular waxes are mostly of the crystalloid type but smooth layer wax is observed inQ. robursubsp.pedunculiflora.Statistical analysis revealed foliar micromorphological features as been diagnostic characters inQuercus.

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