scholarly journals Effects of Powdery Mildew of Grape on Carbon Assimilation Mechanisms of Potted `Chardonnay' Grapevines

HortScience ◽  
2004 ◽  
Vol 39 (7) ◽  
pp. 1670-1673 ◽  
Author(s):  
William R. Nail ◽  
G. Stanley Howell
Keyword(s):  
Chlorophyll Fluorescence ◽  
Stomatal Conductance ◽  
Powdery Mildew ◽  
Photochemical Efficiency ◽  
Carbon Assimilation ◽  
Compensation Point ◽  
Uncinula Necator ◽  
Assimilation Rate ◽  
Factors Affecting ◽  
Stomatal Limitations

Potted grapevines (Vitis vinifera L. `Chardonnay') were inoculated with conidial suspensions of the grapevine pathogen causing powdery mildew of grape (GPM) (Uncinula necator (Schw.) Burr.). Leaves of inoculated and noninoculated vines were studied for the effects of varying light (PAR) and CO2 concentrations on factors affecting carbon assimilation. GPM reduced carboxylation efficiency (k), net CO2 assimilation rate (A), stomatal conductance (gs), and internal CO2 concentration (Ci) under ambient CO2, Amax at >900 ppm CO2, stomatal limitations to A (lg), and photochemical efficiency (Φ) on diseased leaves, while having no effect on the CO2 compensation point (Γ) or the light compensation point (cp). GPM had no significant effect on chlorophyll fluorescence (Fv/Fm).

Altitude of origin influences stomatal conductance and therefore maximum assimilation rate in Southern Beech, Nothofagus cunninghamii

2000 ◽  
Vol 27 (5) ◽  
pp. 451 ◽  
Author(s):  
Mark J. Hovenden ◽  
Tim Brodribb
Keyword(s):  
Stomatal Conductance ◽  
Stomatal Density ◽  
Carbon Assimilation ◽  
Co2 Concentration ◽  
Carboxylation Efficiency ◽  
Assimilation Rate ◽  
Carbon Assimilation Rate ◽  
Southern Beech ◽  
Maximum Stomatal Conductance ◽  
Leaf Biochemistry

Gas exchange measurements were made on saplings of Southern Beech, Nothofagus cunninghamii (Hook.) Oerst. collected from three altitudes (350, 780 and 1100 m above sea level) and grown in a common glasshouse trial. Plants were grown from cuttings taken 2 years earlier from a number of plants at each altitude in Mt Field National Park, Tasmania. Stomatal density increased with increasing altitude of origin, and stomatal con-ductance and carbon assimilation rate were linearly related across all samples. The altitude of origin influenced thestomatal conductance and therefore carbon assimilation rate, with plants from 780 m having a greater photosynthetic rate than those from 350 m. The intercellular concentration of CO2 as a ratio of external CO2 concentration (ci/ca) was similar in all plants despite the large variation in maximum stomatal conductance. Carboxylation efficiency was greater in plants from 780 m than in plants from 350 m. Altitude of origin has a strong influence on the photo-synthetic performance of N. cunninghamii plants even when grown under controlled conditions, and this influence is expressed in both leaf biochemistry (carboxylation efficiency) and leaf morphology (stomatal density).

scholarly journals Characterization of Carbon Assimilation Rate, Stomatal Conductance and Transpiration Rate for Eight Proteaceae Species.

2000 ◽  
Vol 69 (5) ◽  
pp. 576-583 ◽  
Author(s):  
Genaro A. Reynoso ◽  
Masahiro Morokuma ◽  
Yoshie Miura ◽  
Atsushi Hasegawa ◽  
Masanori Goi
Keyword(s):  
Stomatal Conductance ◽  
Transpiration Rate ◽  
Carbon Assimilation ◽  
Assimilation Rate ◽  
Carbon Assimilation Rate

Temperature Dependence of Whole-Leaf Photosynthesis in Eucalyptus pauciflora Sieb. Ex Spreng

1984 ◽  
Vol 11 (6) ◽  
pp. 519 ◽  
Author(s):  
MUF Kirschbaum ◽  
GD Farquhar
Keyword(s):  
Electron Transport ◽  
Stomatal Conductance ◽  
Temperature Dependence ◽  
Carbon Assimilation ◽  
Co2 Assimilation ◽  
Net Assimilation Rate ◽  
Assimilation Rate ◽  
Component Processes ◽  
Net Assimilation ◽  
Photosynthetic Assimilation

The temperature dependence of net photosynthetic assimilation of CO2 by snowgum (Eucalyptus pauciflora Sieb. ex Spreng.) was investigated. CO2 assimilation was divided into its component processes, stomatal and biochemical. The biochemical limitation was investigated with gas-exchange techniques and found to conform well to a recent model of C3 photosynthesis. In line with the model, net assimilation was further divided into ribulose 1,5-bisphosphate (RuP2) regeneration or electron-transport/photophosphorylation limitation, limitation by RuP2 carboxylase/oxygenase (Rubisco; EC 4.1.1.39) activity, together with loss of CO2 in non-photorespiratory respiration. The estimated temperature dependence of electron transport agreed well with one published for uncoupled electron transport, while the estimated temperature dependence of the catalytic activity of Rubisco was slightly less than that reported from biochemical determinations. The estimated rate of non-photorespiratory respiration was about 0.6 times the rate of respiration at night and appeared to have the same temperature dependence. With this information the temperature dependence of the biochemical limitation was modelled. Stomatal conductance was assumed to follow the theory of constant marginal water cost of carbon assimilation (δE/δA) and net assimilation rate at ambient concentration of CO2 was predicted. It was concluded that, for a given Rubisco activity and RuP2-regeneration capacity, both temperature optimum and net assimilation rate at the optimum temperature increased with increasing stomatal conductance.

scholarly journals Photosynthetic behaviour during the leaf ontogeny of rubber tree clones[Hevea brasiliensis (Wild. ex. Adr. de Juss.) Muell. Arg.], in Lavras, MG

2007 ◽  
Vol 31 (1) ◽  
pp. 91-97 ◽  
Author(s):  
Aurélio Antas Miguel ◽  
Luiz Edson Mota de Oliveira ◽  
Paulo Araquém Ramos Cairo ◽  
Davi Melo de Oliveira
Keyword(s):  
Chlorophyll Fluorescence ◽  
Stomatal Conductance ◽  
Chlorophyll Content ◽  
Rubber Tree ◽  
Leaf Age ◽  
Photochemical Efficiency ◽  
Net Photosynthesis ◽  
Leaf Ontogeny ◽  
Chlorophyll Contents ◽  
Internal Co2

This work proposed to investigate changes in the photosynthetic behavior during the leaf ontogeny of the during the leaf development. Up to the 32nd day of leaf age (stage B2), the net photosynthesis was negative due to the inefficiency of the photosynthetic system, and this fact was justified by the following factors: low chlorophyll content, less stomatal conductance, high rubber tree clones PB 235, RRIM 600 and GT 1, in Lavras, MG. The experiment was performed in 2004, between May and July, under field conditions, at the Universidade Federal de Lavras. During the leaf ontogeny, the following characteristics were evaluated: chlorophyll content, gaseous exchanges and chlorophyll fluorescence. The clones presented similar profiles of alterations in the physiological characteristics internal CO2 levels and low chlorophyll fluorescence. From the 37th day of leaf age, net photosynthesis became positive and gradually higher, stimulated by the increases in the chlorophyll contents, photochemical efficiency of photosystem II, carboxylation efficiency, stomatal conductance, transpiration and water use efficiency. Among the clones, photosynthetic behavior was similar, reaching maximum performance on the 57th day of leaf age (stage D), when clone RRIM 600 showed the highest net photosynthesis, differing from the clones PB 235 and GT 1.

scholarly journals Consequences of Injury Caused by Cameraria caryaefoliella (Lepidoptera: Gracillariidae) on Pecan Gas Exchange and Chlorophyll Fluorescence

2013 ◽  
Vol 138 (4) ◽  
pp. 263-266
Author(s):  
Leonardo Lombardini ◽  
Astrid Volder ◽  
Monte L. Nesbitt ◽  
Donita L. Cartmill
Keyword(s):  
Chlorophyll Fluorescence ◽  
Gas Exchange ◽  
Photosynthetic Efficiency ◽  
Photosynthetic Apparatus ◽  
Carbon Assimilation ◽  
Strong Relationship ◽  
Carya Illinoinensis ◽  
Assimilation Rate ◽  
Compensatory Increase ◽  
Injured Area

After an outbreak of blotch leafminer (Cameraria caryaefoliella) on field-grown pecan (Carya illinoinensis) trees in 2010, an experiment was conducted to evaluate the consequences of the injury on carbon assimilation and photosynthetic efficiency, and, in particular, to assess if low-to-moderate injury induces a compensatory increase in photosynthesis. Gas exchange and light-adapted fluorescence were measured on non-injured portions of the leaflet lamina adjacent to the injured area as well as on portions of leaflets that included leafminer injury. Results indicate that damage of the photosynthetic apparatus did not extend beyond the injured areas by leafminers. Furthermore, although a strong relationship between the proportion of leafminer injury and area-based net CO2 assimilation rate of injured leaflet tissue was found, there was no evidence that pecan leaves were able to compensate for leafminer injury by upregulating CO2 assimilation in leaflet tissue that was unaffected.

scholarly journals Content of trans-resveratrol in leaves and berries of interspecific grapevine (Vitis sp.) varieties

2009 ◽  
Vol 26 (Special Issue) ◽  
pp. S13-S17 ◽  
Author(s):  
P. Bábíková ◽  
N. Vrchotová ◽  
J. Tříska ◽  
M. Kyseláková
Keyword(s):  
Powdery Mildew ◽  
Downy Mildew ◽  
Plasmopara Viticola ◽  
Fungal Diseases ◽  
Uncinula Necator ◽  
Botryotinia Fuckeliana

The aim of this project was to study changes in the content of <i>trans</i>-resveratrol in berries and leaves of grapevine (<i>Vitis</i> sp.) infested by fungal diseases, especially by <i>Botryotinia fuckeliana</i> Whetzel, called as grey mildew, <i>Plasmopara viticola</i> (Berk. & M.A. Curtis) Berl & De Toni, called downy mildew and <i>Uncinula necator</i> (Schw.) Burr, called powdery mildew. In our experiments two white and two blue varieties were used. Contents of <i>trans</i>-resveratrol were determined in healthy and infested leaves and in healthy berries. Infested leaves of white varieties contained more <i>trans</i>-resveratrol than those of blue varieties. The content of <i>trans</i>-resveratrol in berries was lower than that in leaves.

Factors Affecting Stomatal Conductance of Bracken Below a Forest Canopy

1984 ◽  
Vol 21 (2) ◽  
pp. 643 ◽  
Author(s):  
J. Roberts ◽  
J. S. Wallace ◽  
R. M. Pitman
Keyword(s):  
Stomatal Conductance ◽  
Forest Canopy ◽  
Factors Affecting
Sign in / Sign up

Export Citation Format

Share Document