The role of the abaxial leaf surface waxes of Lolium spp. in resistance to Erysiphe graminis

Early developmental stages of the sorus in Cyathea fulva show that the indusium is initiated from cells of the protoderm on the abaxial leaf surface, closer to the midvein than the margin of the ultimate segment. This contrasts with earlier work on Alsophila tricolor that reported a marginal origin of the indusium and possible phyletic relations with the marginal sorus in the Dicksoniaceae. This new information is considered in an assessment of the numerous forms of the indusia in five genera of the Cyatheaceae. A series of photographs shows the principal forms and the diversity of sori and indusia in Sphaeropteris, Alsophila, Nephelea, Cyathea, and Cnemidaria, including species of both the paleotropics and neotropics. The figures illustrate the inadequacy of the earlier system of classification of these plants in three main genera based upon the type of indusium. The primary role of the indusium is considered to be the retardation of water loss during sporangial development and sporogenesis.

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Increased papilla formation, a major factor of induced resistance in the barley – Erysiphe graminis f.sp. hordei system

Canadian Journal of Botany ◽

10.1139/b86-289 ◽

1986 ◽

Vol 64 (10) ◽

pp. 2178-2181 ◽

Cited By ~ 17

Author(s):

N. Sahashi ◽

J. Shishiyama

Keyword(s):

Leaf Surface ◽

Specific Resistance ◽

Hyphal Growth ◽

Cellular Responses ◽

Erysiphe Graminis ◽

Powdery Mildew Fungus ◽

Challenge Inoculation ◽

Barley Cultivars ◽

Abaxial Leaf Surface ◽

Papilla Formation

Using two barley cultivars, 'Hanna' and 'Russian No. 12', resistance to Erysiphe graminis DC. f.sp. hordei Em. Marchal induced by preliminary inoculation with a compatible or an incompatible race of the powdery mildew fungus was examined with respect to cellular responses. When the primary leaves of barley seedlings were preliminarily inoculated with a compatible or an incompatible race on the abaxial leaf surface, they became resistant to the disease caused by challenge inoculation with the same pathogen on the adaxial surface. The resistance induced was expressed as decrease of fungal penetration and restriction of hyphal growth. These phenomena seemed to be attributable to the increase of papillae or papillalike structures which do not seem to be responsible for the race-specific resistance. On the basis of these results, it is suggested that the resistance induced may be different from race-specific resistance.

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

Planta ◽

10.1007/s00425-021-03592-6 ◽

2021 ◽

Vol 253 (4) ◽

Author(s):

Sakshi Watts ◽

Rupesh Kariyat

Keyword(s):

Leaf Surface ◽

Abaxial Leaf Surface

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Quantitative Determination of the Role of Lettuce Leaf Structures in Protecting Escherichia coli O157:H7 from Chlorine Disinfection

Journal of Food Protection ◽

10.4315/0362-028x-64.2.147 ◽

2001 ◽

Vol 64 (2) ◽

pp. 147-151 ◽

Cited By ~ 89

Author(s):

KAZUE TAKEUCHI ◽

JOSEPH F. FRANK

Keyword(s):

Escherichia Coli ◽

Leaf Surface ◽

Dead Cell ◽

Escherichia Coli O157 ◽

E Coli ◽

Chlorine Disinfection ◽

Sytox Green ◽

Tissue Surface ◽

Confocal Scanning

Viability of Escherichia coli O157:H7 cells on lettuce leaves after 200 mg/liter (200 ppm) chlorine treatment and the role of lettuce leaf structures in protecting cells from chlorine inactivation were evaluated by confocal scanning microscopy (CSLM). Lettuce samples (2 by 2 cm) were inoculated by immersing in a suspension containing 109 CFU/ml of E. coli O157: H7 for 24 ± 1 h at 4°C. Rinsed samples were treated with 200 mg/liter (200 ppm) chlorine for 5 min at 22°C. Viability of E. coli O157:H7 cells was evaluated by CSLM observation of samples stained with Sytox green (dead cell stain) and Alexa 594 conjugated antibody against E. coli O157:H7. Quantitative microscopic observations of viability were made at intact leaf surface, stomata, and damaged tissue. Most E. coli O157:H7 cells (68.3 ± 16.2%) that had penetrated 30 to 40 μm from the damaged tissue surface remained viable after chlorine treatment. Cells on the surface survived least (25.2 ± 15.8% survival), while cells that penetrated 0 to 10 μm from the damaged tissue surface or entered stomata showed intermediate survival (50.8 ± 13.5 and 45.6 ± 9.7% survival, respectively). Viability was associated with the depth at which E. coli O157:H7 cells were in the stomata. Although cells on the leaf surface were mostly inactivated, some viable cells were observed in cracks of cuticle and on the trichome. These results demonstrate the importance of lettuce leaf structures in the protection of E. coli O157:H7 cells from chlorine inactivation.

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THE ROLE OF FLAG LEAVES AND AWNS IN THE FORMATION OF WINTER WHEAT PRODUCTIVITY (REVIEW)

Grain Economy of Russia ◽

10.31367/2079-8725-2018-58-4-32-34 ◽

2018 ◽

pp. 32-34 ◽

Cited By ~ 1

Author(s):

S. N. Gromova ◽

P. I. Kostylev

Keyword(s):

Winter Wheat ◽

Leaf Surface ◽

Wheat Yield ◽

Complex Trait ◽

Genetic System ◽

Flag Leaves ◽

Grain Productivity ◽

Agricultural Yield ◽

Yield Formation

The article presents the results of the conducted analysis of research works about the effect of size of flag leaves and awns on winter wheat productivity. The genetic potential of the variety, which can be realized on the basis of its biologic characteristics largely influences on its productivity. Productivity is a complex trait that is controlled by a complex genetic system closely connected with many factors of environment. The size and duration of assimilation surface are the most important components of biologic and agricultural yield of wheat. Many researchers showed that the amount and duration of photosynthesis by leaf surface are the main factors limiting productivity in the definite conditions of growing, and the size of leaf surface correlates with grain productivity. Photosynthetic parts of winter wheat include not only leaves, but also stems, heads, awns, etc. The conducted analysis of the literature showed that there is no consensus on the effect of flag leaves on wheat yield formation. Therefore it’s necessary to fulfill the study and evaluation of the part of flag leaves and awns in the formation of winter soft wheat productivity in the Rostov region.

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Effects of Powdery Mildew on the Leaf Surface Waxes of Wheat

Plant Lipid Metabolism ◽

10.1007/978-94-015-8394-7_110 ◽

1995 ◽

pp. 414-416

Author(s):

Abdelrahman Almihanna ◽

Dorothy Lösel

Keyword(s):

Powdery Mildew ◽

Leaf Surface ◽

Surface Waxes

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

Botanical Journal of the Linnean Society ◽

10.1093/botlinnean/boz072 ◽

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.

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

Weed Science ◽

10.1017/s0043174500094200 ◽

1996 ◽

Vol 44 (3) ◽

pp. 469-475 ◽

Cited By ~ 20

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%.

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

Phytotaxa ◽

10.11646/phytotaxa.374.3.1 ◽

2018 ◽

Vol 374 (3) ◽

pp. 185 ◽

Cited By ~ 3

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.

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

Plant Disease ◽

10.1094/pdis-06-19-1285-re ◽

2020 ◽

Vol 104 (4) ◽

pp. 1167-1174 ◽

Cited By ~ 1

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.

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