Chilling and photosynthetic productivity of field grown maize (Zea mays); changes in the parameters of the light-response curve, canopy leaf CO2 assimilation rate and crop radiation-use efficiency

1993 ◽  
Vol 38 (2) ◽  
pp. 125-133 ◽  
Author(s):  
C. M. Stirling ◽  
V. H. Rodrigo ◽  
J. Emberru
Keyword(s):  
Zea Mays ◽  
Response Curve ◽  
Light Response ◽  
Co2 Assimilation ◽  
Assimilation Rate ◽  
Light Response Curve ◽  
Co2 Assimilation Rate ◽  
Photosynthetic Productivity ◽  
Use Efficiency ◽  
Radiation Use

The impacts of leaf shape and arrangement on light interception and potential photosynthesis in southern beech (Nothofagus cunninghamii)

2004 ◽  
Vol 31 (5) ◽  
pp. 471 ◽  
Author(s):  
Stephen O. Kern ◽  
Mark J. Hovenden ◽  
Gregory J. Jordan
Keyword(s):  
Flux Density ◽  
Response Curve ◽  
Leaf Shape ◽  
Carbon Assimilation ◽  
Light Response ◽  
Light Interception ◽  
Photon Flux ◽  
Assimilation Rate ◽  
Light Response Curve ◽  
Carbon Assimilation Rate

The impact of differences in leaf shape, size and arrangement on the efficiency of light interception, and in particular the avoidance of photoinhibition, are poorly understood. We therefore estimated light exposure of branches in the cool temperate rainforest tree, Nothofagus cunninghamii (Hook.) Oerst., in which leaf shape, size and arrangement vary systematically with altitude and geographic origin. Measurements of incident photosynthetic photon flux density (PPFD) were made in the laboratory at solar angles corresponding to noon at summer solstice, winter solstice and equinox on branches collected from a common garden experiment. Tasmanian plants showed more self-shading than Victorian plants in summer and equinox. This was related to branch angle, leaf arrangement and leaf shape. Using a modelled light response-curve, we estimated the carbon assimilation rate and the flux density of excess photons at different incident PPFD. Victorian plants had higher predicted assimilation rates than Tasmanian plants in summer and equinox, but were exposed to substantially greater levels of excess photons. Because of the shape of the light-response curve, self-shading appears to reduce the plant's exposure to excess photons, thus providing photoprotection, without substantially reducing the carbon assimilation rate. This is dependent on both regional origin and season.

Comparison between modified exponential model and common models of light-response curve

2013 ◽  
Vol 36 (12) ◽  
pp. 1277-1285 ◽  
Author(s):  
Wei-Ying CHEN ◽  
Zhen-Yong CHEN ◽  
Fu-Yan LUO ◽  
Zheng-Song PENG ◽  
Mao-Qun YU
Keyword(s):  
Response Curve ◽  
Light Response ◽  
Exponential Model ◽  
Light Response Curve

scholarly journals Salt tolerance and regulation of gas exchange and hormonal homeostasis by auxin-priming in wheat

2013 ◽  
Vol 48 (9) ◽  
pp. 1210-1219 ◽  
Author(s):  
Muhammad Iqbal ◽  
Muhammad Ashraf
Keyword(s):  
Abscisic Acid ◽  
Gas Exchange ◽  
Acid Concentration ◽  
Spring Wheat ◽  
Indoleacetic Acid ◽  
Co2 Assimilation ◽  
Assimilation Rate ◽  
Co2 Assimilation Rate ◽  
Net Co2 Assimilation Rate ◽  
Net Co2 Assimilation

The objective of this work was to assess the regulatory effects of auxin-priming on gas exchange and hormonal homeostasis in spring wheat subjected to saline conditions. Seeds of MH-97 (salt-intolerant) and Inqlab-91 (salt-tolerant) cultivars were subjected to 11 priming treatments (three hormones x three concentrations + two controls) and evaluated under saline (15 dS m-1) and nonsaline (2.84 dS m-1) conditions. The priming treatments consisted of: 5.71, 8.56, and 11.42 × 10-4 mol L-1 indoleacetic acid; 4.92, 7.38, and 9.84 × 10-4 mol L-1 indolebutyric acid; 4.89, 7.34, and 9.79 × 10-4 mol L-1 tryptophan; and a control with hydroprimed seeds. A negative control with nonprimed seeds was also evaluated. All priming agents diminished the effects of salinity on endogenous abscisic acid concentration in the salt-intolerant cultivar. Grain yield was positively correlated with net CO2 assimilation rate and endogenous indoleacetic acid concentration, and it was negatively correlated with abscisic acid and free polyamine concentrations. In general, the priming treatment with tryptophan at 4.89 × 10-4 mol L-1 was the most effective in minimizing yield losses and reductions in net CO2 assimilation rate, under salt stress conditions. Hormonal homeostasis increases net CO2 assimilation rate and confers tolerance to salinity on spring wheat.

scholarly journals Foliar phosphorus supply and CO2 assimilation in common bean (Phaseolus vulgaris L.) under water deficit

2006 ◽  
Vol 18 (3) ◽  
pp. 407-411 ◽  
Author(s):  
Mauro G. dos Santos ◽  
Rafael V. Ribeiro ◽  
Marcelo G. Teixeira ◽  
Ricardo F. de Oliveira ◽  
Carlos Pimentel
Keyword(s):  
Phaseolus Vulgaris ◽  
Common Bean ◽  
Water Deficit ◽  
Co2 Assimilation ◽  
Assimilation Rate ◽  
Phaseolus Vulgaris L ◽  
Co2 Assimilation Rate ◽  
Net Co2 Assimilation ◽  
Foliar Phosphorus ◽  
Regulation Of Photosynthesis

Two common bean cultivars were grown in pots under greenhouse conditions. Plants were submitted to a foliar Pi spray two days before suspending irrigation, what enhanced net CO2 assimilation rate of Ouro Negro cultivar but did not change significantly the photosynthesis of Carioca cultivar under both water deficit and rehydration periods. The results revealed that a foliar Pi spray induced an up-regulation of photosynthesis in common bean under mild water deficit, with this effect being genotype-dependent.

scholarly journals MORPHOPHYSIOLOGICAL CHARACTERISTICS OF ARABIC COFFEE

Nativa ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 36-43
Author(s):  
Lucas Aparecido Manzani Lisboa ◽  
Matheus Luís Oliveira Cunha ◽  
Fernando Takayuki Nakayama ◽  
Paulo Alexandre Monteiro de Figueiredo ◽  
Ronaldo da Silva Viana ◽  
...  
Keyword(s):  
Plant Physiology ◽  
Coffea Arabica ◽  
Plant Morphology ◽  
Co2 Assimilation ◽  
Climatic Conditions ◽  
Assimilation Rate ◽  
Abaxial Epidermis ◽  
Internal Morphology ◽  
Use Efficiency ◽  
Best Fit

The understanding of the behavior of each cultivar under adverse climatic conditions is important in the choice of plants that best fit the region to be inserted. Due to the large number of cultivars available on the market it makes it difficult for producers to choose which material to plant. In view of the above, this study aimed to know the morphophysiological characteristics of coffee. The experimental design was in randomized blocks with 10 treatments, that is, arabic coffee varieties: Catuai IAC62; Catuai IAC99; Ouro IAC4397; Tupi RN IAC1669-13; Obatã IAC1669-20; Mundo Novo IAC379-24; Mundo Novo IAC 388-17-2; Mundo Novo SH3 Faz São José; Bourbon IACJ15 and Icatu IAC 2944-11 and with four replications totaling 40 plots, where each plot was composed of seven plants. The Mundo Novo IAC 388-17-2 coffee variety shows higher yield in the seventh year of cultivation. Variety of Bourbon IACJ15 coffee presented water use efficiency (EUW) which did not reflect in higher productivity. The Catuai V IAC99 arabica coffee variety stood out in the internal morphology of the leaves. The thickness of the adaxial and abaxial epidermis (TADE and TABE) and the CO2 assimilation rate (A) showed negative correlations with the productivity of processed coffee bags. Keywords: Coffea arabica; plant morphology; plant physiology; varieties.

Effects of planting patterns and sowing densities on grain-filling, radiation use efficiency and yield of maize (Zea mays L.) in semi-arid regions

2018 ◽  
Vol 201 ◽  
pp. 287-298 ◽  
Author(s):  
Qianmin Jia ◽  
Lefeng Sun ◽  
Hongyan Mou ◽  
Shahzad Ali ◽  
Donghua Liu ◽  
...  
Keyword(s):  
Zea Mays ◽  
Arid Regions ◽  
Zea Mays L ◽  
Grain Filling ◽  
Radiation Use Efficiency ◽  
Use Efficiency ◽  
Radiation Use ◽  
Semi Arid
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