Search

Start Over Subject stomatal density

1. Anatomical and eco-physiological changes in leaves of couch-grass (Elymus repens L.), a temperate loess grassland species, after 7 years growth under elevated CO2 concentration

Creator:
Engloner, A. I., Kovács, D., Balogh, J., and Tuba, Z.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
mesophyll, net photosynthetic rate, phloem, sclerenchyma, stomatal conductance, stomatal density, tracheary, transpiration rate, and water use efficiency
Language:
Multiple languages
Description:
Leaf anatomy and eco-physiology of Elymus repens, a temperate loess grassland species, were determined after seven years of exposure to 700 μmol (CO2) mol-1 (EC). EC treatment resulted in significant reduction of stomatal density on both surfaces of couch-grass leaves. Thickness of leaves and that of the sclerenchyma tissues between the vessels and the adaxial surfaces, the area of vascular bundle, and the volumes of phloem and tracheary increased at EC while abaxial epidermis and the sclerenchyma layer between the vessel and the abaxial surface were thicker at ambient CO2 concentration (AC). Stomatal conductance and transpiration rates were lower in EC, while net CO2 assimilation rate considerably increased at EC exposure. Contents of soluble sugars and starch were higher in EC-treated couch-grass leaves than in plants grown at AC. and A. I. Engloner ... [et al.].
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

2. Gas exchange response of barley and pea cultivars to altitude variation in Himalaya

Creator:
Vats, S. K., Kumar, N., and Kumar, S.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
acclimation, Hordeum, photosynthesis, Pisum, pore length, species differences, stomatal conductance, stomatal density, and stomatal index
Language:
Multiple languages
Description:
Leaf stomatal density (SD), net photosynthetic rates (PN), and stomatal conductance (gs) of Hordeum vulgare and Pisum sativum cultivars in Himalaya increased with altitude. Higher PN and leaf temperature under low CO2 partial pressure at high altitudes could evoke a higher gs and SD to allow sufficient influx of CO2 as well as more efficient leaf cooling through transpiration. and S. K. Vats, N. Kumar, S. Kumar.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

3. Photosynthetic and stomatal responses of two tropical and two temperate trees to atmospheric humidity

Creator:
Park, S.-Y. and Furukawa, A.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
Daphniphyllum macropodum, Eugenia grandis, intercellular CO2 concentration, Pongamia pinnata, stomatal density, transpiration rate, and Viburnum awabuki
Language:
Multiple languages
Description:
The effects of leaf to air vapour pressure differences (ΔW) on net photosynthetic rate (PN) and stomatal conductance (gs) were examined in the leaves of two tropical rain forest trees, Eugenia grandis and Pongamia pinnata, and two temperate evergreen trees, Viburnum awabuki and Daphniphyllum macropodum. A single leaf was set inside a small chamber and ΔW was varied from 7 to 24 mmol mol-1 at 25 and 500 μmol m-2 s-1 of photon flux density. PN and gs of the two tropical rain forest trees decreased with increasing ΔW, while the two temperate evergreen trees were not highly responsive to ΔW. P. pinnata was more sensitive to ΔW in its stomatal response, and had a higher stomatal density and higher stomatal index than did the two temperate trees and another tropical tree. Significant reductions i n gs and intercellular CO2 concentrations in the two tropical trees at high ΔW suggest that the decline of PN was due to the decrease in gs. The responses of PN and gs indicated that the tropical trees were more sensitive to ΔW than were the temperate ones. and S.-Y. Park, A. Furukawa.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

4. Photosynthetic characterization of Australian pitcher plant Cephalotus follicularis

Creator:
Pavlovič, A.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
botanika, botany, carnivorous plants, Cephalotus, chlorophyll, chlorophyll fluorescence, pitcher plants, photosynthesis, respiration, and stomatal density
Language:
Multiple languages
Description:
Australian carnivorous pitcher plant Cephalotus follicularis Labill. produces two types of leaves. During the spring time, the plant produces a foliage type of noncarnivorous leaf called lamina. Later, the second type of leaf is produced - carnivorous pitcher. Using simultaneous measurements of gas exchange and chlorophyll (Chl) fluorescence photosynthetic efficiency of these two distinct forms of leaves were compared. In addition stomatal density, an important component of gas exchange, and Chl concentration were also determined. Pitcher trap had lower net photosynthetic rate (PN) in comparison to noncarnivorous lamina, whereas the rate of respiration (RD) was not significantly different. This was in accordance with lower stomatal density and Chl concentration in the pitcher trap. On the other hand maximum quantum yield of PSII (Fv/Fm) and effective quantum yield of photochemical energy conversion in PSII (ΦPSII) was not significantly different. Nonphotochemical quenching (NPQ) was significantly higher in the lamina at higher irradiance. These data are in accordance with hypothesis that changing the leaf shape in carnivorous plants to make it a better trap generally makes it less efficient at photosynthesis. However, the pitcher of Cephalotus had much higher PN than it was expected from the data set of the genus Nepenthes. Because it is not possible to optimize for contrasting function such as photosynthesis and carnivory, it is hypothesized that Cephalotus pitchers are less elaborated for carnivorous function than the pitchers of Nepenthes. and A. Pavlovič.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

5. Quality of supplementary LED lighting effects on growth and photosynthesis of two different Lactuca recombinant inbred lines (RILs) grown in a tropical greenhouse

Creator:
Choong, T. W., He, J., Qin, L., and Lee, S. K.
Format:
print, bez média, and svazek
Type:
model:article and TEXT
Subject:
pigmenty, světelné diody, fotosyntéza, pigments, light emitting diodes, photosynthesis, electron transport rate, leaf expansion, light- and CO2-saturated net photosynthetic rate, photochemical and nonphotochemical quenching, stomatal density, 2, and 581
Language:
Multiple languages
Description:
LED lamps with various combinations of red (R) and blue (B) wavelengths were used to supplement sunlight for the growth of a heat-resistant (HR) and heat-sensitive (HS) recombinant inbred lines (RIL) of lettuce. The RB-LED ratios were 100R:0B (0B), 92R:8B (8B), 84R:16B (16B), and 76R:24B (24B) with an equal PPFD of 100 μmol m-2 s-1. The greatest leaf expansion rates were observed at 8B for both genotypes. All HR-RILs had similar values of growth parameters and specific leaf area (SLA). However, higher values of growth parameters were observed in HS-RIL with 0B, 8B, and 16B than that under 24B and sunlight. Furthermore, HS-RIL had higher SLA under 0B compared to other conditions. Photosynthetic light-use efficiency and maximal oxygen evolution rate were the lowest under 8B for both genotypes. The quality of LED lighting, if provided, seemed to implicate genotype dependence, probably as a result of their different sensitivities to heat stress., T. W. Choong, J. He, L. Qin, S. K. Lee., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

6. Water relations and leaf anatomy of the tropical species, Jatropha gossypifolia and Alternanthera crucis, grown under an elevated CO2 concentration

Creator:
Rengifo, E., Urich, R., and Herrera, A.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
drought, parenchyma, open-top chamber, osmotic potential, pressure potential, stomatal density, volumetric elasticity modulus, water potential, and water supply
Language:
Multiple languages
Description:
In order to address the question of how elevated CO2 concentration (EC) will affect the water relations and leaf anatomy of tropical species, plants of Jatropha gossypifolia L. and Alternanthera crucis (Moq.) Bondingh were grown in five EC open top chambers (677 μmol mol-1) and five ambient CO2 concentration (AC) open top chambers (454 μmol mol-1) with seasonal drought. No effect of EC was found on morning xylem water potential, leaf osmotic potential, and pressure potential of plants of J. gossypifolia. In A. crucis EC caused a significant increase in morning xylem water potential of watered plants, a decrease in osmotic potential, and an increase of 24-79 % in pressure potential of moderately droughted plants. This ameliorated the effects of drought. Stomatal characteristics of both leaf surfaces of J. gossypifolia and A. crucis showed time-dependent, but not [CO2]-dependent changes. In J. gossypifolia the thickness of whole leaf, palisade parenchyma, and spongy parenchyma, and the proportion of whole leaf thickness contributed by these parenchymata decreased significantly in response to EC. In A. crucis EC caused an increase in thickness of whole leaf, bundle sheath, and mesophyll, while the proportion of leaf cross-section comprised by the parenchymata remained unchanged. These effects disappeared with time under treatment, suggesting that acclimation of the leaf anatomy to the chambers and to EC took place in the successive flushes of leaves produced during the experiment. and E. Rengifo, R. Urich, A. Herrera.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public