scholarly journals Glycosylated Aroma Compound Responses in ‘Riesling’ Wine Grapes to Cluster Exposure and Vine Yield

2013 ◽  
Vol 23 (5) ◽  
pp. 581-588 ◽  
Author(s):  
James M. Meyers ◽  
Gavin L. Sacks ◽  
Justine E. Vanden Heuvel
Keyword(s):  
Light Exposure ◽  
Cultural Influences ◽  
Light Response ◽  
Aroma Compounds ◽  
Photon Flux ◽  
Aroma Compound ◽  
Wine Grapes ◽  
Response Curves ◽  
Exposure Metrics ◽  
The Impact

Concentrations of aroma precursor compounds in ‘Riesling’ wine grapes (Vitis vinifera) are reported to correlate with fruit zone cluster exposure, although optimal cultural influences with respect to exposure timing and canopy assessment methods have not been established. To determine the impact of cluster exposure on concentrations of potential aroma compounds, correlations between light exposure metrics during the growing season and relative concentrations of eight representative aroma compounds at harvest were determined. The aroma compounds were carbon-13 (C13) norisoprenoids [1,1,6-trimethyl-1,2-dihydronaphthalene (TDN), β-damascenone, and vitispirane], monoterpenes (linalool oxide, α-terpineol), and phenolics (4-vinylguaiacol, vanillin and eugenol). Cluster exposure was determined using metrics of varying spatial precision [percent interior cluster (PIC), cluster exposure layer (CEL), ln(CEL), cluster exposure flux availability (CEFA), and the percent ambient photosynthetic photon flux (PPF)] at two sites and two phenological stages (fruit set and veraison) in two consecutive seasons (2008 and 2009). Pairwise combinations of cluster exposure metrics and compounds resulted in 360 permutations, of which 22 were significant. Response data suggested that none of the compounds studied respond to variable cluster exposure levels below 20% of ambient sunlight (CEFA < 0.2), and that low cluster exposure may be particularly effective in minimizing C13 norisoprenoid concentrations at harvest. Yield components were also tested but found to have lower R2 values compared with cluster exposure metrics. Active canopy management, in which vine vigor and fruit exposure are independently controlled, is likely to be more effective in influencing potential aroma compounds than selectively harvesting for naturally occurring variation in cluster exposure. In comparing the relative predictive strength among metrics, CEFA ≅ ln(CEL) > CEL > PIC ≅ percent PPF, suggesting that cluster exposure metrics with greater spatial sensitivity are more effective for establishing light response curves.

scholarly journals Temperature response of photosynthesis and its interaction with light intensity in sweet orange leaf discs under non-photorespiratory condition

2006 ◽  
Vol 30 (4) ◽  
pp. 670-678 ◽  
Author(s):  
Rafael Vasconcelos Ribeiro ◽  
Eduardo Caruso Machado ◽  
Ricardo Ferraz de Oliveira
Keyword(s):  
Sweet Orange ◽  
Photochemical Efficiency ◽  
Temperature Response ◽  
Light Response ◽  
Photon Flux ◽  
O2 Evolution ◽  
Response Curves ◽  
Leaf Discs ◽  
Light Response Curves ◽  
Heat Effects

This study aimed to evaluate the response of photosynthesis (A), given by photosynthetic O2 evolution, to increasing temperature from 25 to 50ºC in sweet orange (Citrus sinensis (L.) Osbeck) leaf discs under non-photorespiring conditions. In order to evaluate the response of gross photosynthesis to temperature and the balance between photosynthetic and respiratory activities, respiration (Rd) rates were also measured, i.e. the O2 uptake in each temperature. In addition, light response curves of photosynthesis were performed by varying the photosynthetic photon flux density (PPFD) from 0 to 1160 µmol m-2 s-1 at 25 and 40ºC. The highest A values were observed at 35 and 40ºC, whereas the highest Rd values were noticed at 50ºC. A higher relationship A/Rd was found at 30 and 35ºC, suggesting an optimum temperature of 35ºC when considering the balance between photosynthesis and respiration under non-photorespiring condition. Overall, heat effects on plant metabolism were more evident when evaluating the relationship A/Rd. In light response curves, higher A values were also found at 40ºC under PPFD higher than 300 µmol m-2 s-1. Light saturation point of photosynthesis was increased at 40ºC, without significant change of quantum efficiency under low PPFD. Respiration was also enhanced at 40ºC, and as a consequence, the light compensation point increased. The better photosynthetic performance at 35-40ºC was supported by higher photochemical efficiency in both light and temperature response curves. The temperature-dependence of photosynthesis was affected by growth temperature, i.e. a high air temperature during plant growth is a probable factor leading to a higher photosynthetic tolerance to heat stress.

scholarly journals Photochemical Acclimation of Three Contrasting Species to Different Light Levels: Implications for Optimizing Supplemental Lighting

2017 ◽  
Vol 142 (5) ◽  
pp. 346-354 ◽  
Author(s):  
Shuyang Zhen ◽  
Marc W. van Iersel
Keyword(s):  
Electron Transport ◽  
Light Intensity ◽  
Photochemical Efficiency ◽  
Light Response ◽  
High Light ◽  
Photon Flux ◽  
Ambient Light ◽  
Response Curves ◽  
Low Light ◽  
Supplemental Lighting

Photosynthetic responses to light are dependent on light intensity, vary among species, and can be affected by acclimation to different light environments (e.g., light intensity, spectrum, and photoperiod). Understanding how these factors affect photochemistry is important for improving supplemental lighting efficiency in controlled-environment agriculture. We used chlorophyll fluorescence to determine photochemical light response curves of three horticultural crops with contrasting light requirements [sweetpotato (Ipomea batatas), lettuce (Lactuca sativa), and pothos (Epipremnum aureum)]. We also quantified how these responses were affected by acclimation to three shading treatments-full sun, 44% shade, and 75% shade. The quantum yield of photosystem II (ΦPSII), a measure of photochemical efficiency, decreased exponentially with increasing photosynthetic photon flux (PPF) in all three species. By contrast, linear electron transport rate (ETR) increased asymptotically with increasing PPF. Within each shading level, the high-light-adapted species sweetpotato used high light more efficiently for electron transport than light-intermediate lettuce and shade-tolerant pothos. Within a species, plants acclimated to high light (full sun) tended to have higher ΦPSII and ETR than those acclimated to low light (44% or 75% shade). Nonphotochemical quenching (NPQ) (an indicator of the amount of absorbed light energy that is dissipated as heat) was upregulated with increasing PPF; faster upregulation was observed in pothos as well as in plants grown under 75% shade. Our results have implications for supplemental lighting: supplemental light is used more efficiently and results in a greater increase in ETR when provided at low ambient PPF. In addition, high-light-adapted crops and crops grown under relatively high ambient light can use supplemental light more efficiently than low-light-adapted crops or those grown under low ambient light.

scholarly journals Light response and photosynthesis in sorghum under field conditions

MAUSAM ◽  
2022 ◽  
Vol 46 (3) ◽  
pp. 303-306
Author(s):  
Y. R. KENJLE ◽  
M. C. VARSHNEYA ◽  
T. R. U. NAIDU
Keyword(s):  
Correlation Coefficients ◽  
Light Response ◽  
Photosynthetic Photon Flux Density ◽  
Field Conditions ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Response Curves ◽  
Light Response Curves ◽  
Air Temperatures ◽  
Rate Of Photosynthesis

ABSTRACT. The diurnal variation of rate of photosynthesis (l') with photosynthetic photon flux density (PPFD) model of light response curves and the relationship between PPFD and P were studied for two postmonsoon (rabi) sorghum genotypes, viz.. M35- I and RSV-9R under field conditions at Pune. The half maximal values. i.e., PPFD level at which P=Pmax/2 obtained were 1251 and 937 umolm-2s-1 for M35-l and RSV.9R respectively. The potential rates of photosynthesis were 65,79 and 64.52  umolm-2S-1 whereas the observed maximum rates of photosynthesis were lower. 40.93 and 46.66 umolm-2s-1 in M35-1 and RSV-9R Respectively, due to effect of air temperatures under the field conditions, n1e maximum rate of photosynthesis determined from the model decreased with delay in the sowing of the crop. Correlation coefficients between PPFD and rate of photosynthesis were 0,794 and 0,708 for M35-1 and RSV-9R respectively. The PPFD received and rate of photosynthesis decreased significantly with delay in sorghum sowing.    

scholarly journals (81) Fine Fescues and Shade Tolerance

HortScience ◽  
2005 ◽  
Vol 40 (4) ◽  
pp. 1041A-1041
Author(s):  
Tara E. Paranick ◽  
N. Suzanne Lang
Keyword(s):  
Poa Pratensis ◽  
Block Design ◽  
Light Response ◽  
Kentucky Bluegrass ◽  
Potential Method ◽  
State University ◽  
Response Curves ◽  
Red Fescue ◽  
Light Response Curves ◽  
The Impact

Shaded environments present major obstacles for establishing high quality, persistent, and resistant turfs. Exogenous fructose applications are being examined as a potential method to counteract the effects of shade on turf. This work examines the effectiveness of fructose applications under different light levels on two fine leaf fescue cultivars: chewings fescue (Festucarubra var. commutata) `SR5100' and creeping red fescue (Festucarubra var. rubra) `Dawson'. The experiment was conducted at Michigan State University, East Lansing, inside a simulated dome environment. The experiment was a randomized complete-block design that began 21 Oct. 2004 with two main factors: light and fructose. There were three light treatments: ambient light (shaded); supplemental high light; and supplemental low light. Fructose (0% or 1.25% weight/volume), dissolved in water with an organosilicone adjuvant, was applied once per week. Quality and color ratings, clippings, core samples, density, and leaf reflectance were recorded. In addition, light response curves (LRC) were taken inside an Econoair® growth chamber using a LI-COR-6400® on the fine fescues, kentucky bluegrass (Poa pratensis) `Cynthia', and bermudagrass (Cyondon dactylon) `Princess'. Preliminary results show that fructose had no significant effect in each light treatment for turf quality and color. However, fructose had a significant impact on clipping weights and density. The LRC specified the required and potential carbon needs as well as indicated the threshold levels, respectively, by species. The impact of fructose alone and in combination with supplemental light on photosynthesis efficiency will be presented.

scholarly journals Cannabis Yield, Potency, and Leaf Photosynthesis Respond Differently to Increasing Light Levels in an Indoor Environment

2021 ◽  
Vol 12 ◽  
Author(s):  
Victoria Rodriguez-Morrison ◽  
David Llewellyn ◽  
Youbin Zheng
Keyword(s):  
Indoor Environment ◽  
Treatment Effects ◽  
Cannabis Sativa ◽  
Light Response ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Plant Responses ◽  
Production Environment ◽  
Response Curves ◽  
Leaf Level

Since the recent legalization of medical and recreational use of cannabis (Cannabis sativa) in many regions worldwide, there has been high demand for research to improve yield and quality. With the paucity of scientific literature on the topic, this study investigated the relationships between light intensity (LI) and photosynthesis, inflorescence yield, and inflorescence quality of cannabis grown in an indoor environment. After growing vegetatively for 2 weeks under a canopy-level photosynthetic photon flux density (PPFD) of ≈425 μmol·m−2·s−1 and an 18-h light/6-h dark photoperiod, plants were grown for 12 weeks in a 12-h light/12-h dark “flowering” photoperiod under canopy-level PPFDs ranging from 120 to 1,800 μmol·m−2·s−1 provided by light emitting diodes. Leaf light response curves varied both with localized (i.e., leaf-level) PPFD and temporally, throughout the flowering cycle. Therefore, it was concluded that the leaf light response is not a reliable predictor of whole-plant responses to LI, particularly crop yield. This may be especially evident given that dry inflorescence yield increased linearly with increasing canopy-level PPFD up to 1,800 μmol·m−2·s−1, while leaf-level photosynthesis saturated well-below 1,800 μmol·m−2·s−1. The density of the apical inflorescence and harvest index also increased linearly with increasing LI, resulting in higher-quality marketable tissues and less superfluous tissue to dispose of. There were no LI treatment effects on cannabinoid potency, while there were minor LI treatment effects on terpene potency. Commercial cannabis growers can use these light response models to determine the optimum LI for their production environment to achieve the best economic return; balancing input costs with the commercial value of their cannabis products.

scholarly journals Cannabis Yield, Potency, and Leaf Photosynthesis Respond Differently to 1 Increasing Light Levels in an Indoor Environment

2021 ◽  
Author(s):  
Victoria Rodriguez Morrison ◽  
David Llewellyn ◽  
Youbin Zheng
Keyword(s):  
Indoor Environment ◽  
Treatment Effects ◽  
Cannabis Sativa ◽  
Light Response ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Plant Responses ◽  
Production Environment ◽  
Response Curves ◽  
Leaf Level

Since the recent legalization of medical and recreational use of cannabis (Cannabis sativa L.) in many regions worldwide, there has been high demand for research to improve yield and quality. With the paucity of scientific literature on the topic, this study investigated the relationships between light intensity (LI) and photosynthesis, inflorescence yield, and inflorescence quality of cannabis grown in an indoor environment. After growing vegetatively for 2 weeks under a canopy-level photosynthetic photon flux density (PPFD) of &asymp; 425 &mu;mol&middot;m-2&middot;s-1 and an 18-h light/6-h dark photoperiod, plants were grown for 12 weeks in a 12-h light/12-h dark &lsquo;flowering&rsquo; photoperiod under canopy-level PPFDs ranging from 120 to 1800 &mu;mol&middot;m-2&middot;s-1 provided by light emitting diodes. Leaf light response curves varied both with localized (i.e., leaf-level) PPFD and temporally, throughout the flowering cycle. Therefore, it was concluded that the leaf light response is not a reliable predictor of whole- plant responses to LI, particularly crop yield. This may be especially evident given that dry inflorescence yield increased linearly with increasing canopy-level PPFD up to 1800 &mu;mol&middot;m-2&middot;s-1, while leaf-level photosynthesis saturated well below 1800 &mu;mol&middot;m-2&middot;s-1. The density of the apical inflorescence and harvest index also increased linearly with increasing LI, resulting in higher-quality marketable tissues and less superfluous tissue to dispose of. There were no LI treatment effects on cannabinoid potency, while there were minor LI treatment effects on terpene potency. Commercial cannabis growers can use these light response models to determine the optimum LI for their production environment to achieve the best economic return; balancing input costs with the commercial value of their cannabis products.

scholarly journals Salt and Aroma Compound Distributions Influence Flavour Release and Temporal Perception While Eating Hot-Served Flans

Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1300
Author(s):  
Marion Emorine ◽  
Chantal Septier ◽  
Christophe Martin ◽  
Sylvie Cordelle ◽  
Etienne Sémon ◽  
...  
Keyword(s):  
Salt Content ◽  
Optimal Solution ◽  
Proton Transfer Reaction ◽  
Aroma Compounds ◽  
Aroma Compound ◽  
Taste Intensity ◽  
Heterogeneous Distribution ◽  
Flavour Compounds ◽  
Flight Mass Spectrometry

To counteract the negative effect of salt overconsumption on health, strategies have been developed to reduce the salt content in food products. Among them, two promising strategies based on odour-induced saltiness enhancement and the heterogeneous distribution of flavour compounds were combined and assessed in four-layer cream-based snacks. To investigate the relationship between saltiness enhancement, temporal release and perception of flavour compounds in hot snacks with heterogeneous distribution of salt and aroma compounds, complementary techniques were used: nose space PTR-Tof-MS (Proton Transfer Reaction-Time of Flight–Mass Spectrometry) to assess the release of aroma compounds in vivo, and ATI (Alternate Time-Intensity) and TDS Temporal Dominance of Sensations) to evaluate perception as a function of time. The obtained results confirmed that the strategy of concentrating salt in the outer layer of a multilayer product was the optimal solution with respect to taste intensity. Heterogeneous salt distribution decreased aroma compound release and consequently aroma intensity but in different ways according to both salt and added aroma distribution in the food matrix. The salty taste enhancement could be due to the initial strong dominance of the salty sensation at the very beginning of the eating process. The involved mechanisms rely on a combination of physico-chemical and perceptual effects which are not clear yet.

Residents’ perceptions of the impact of tourism in Abu Dhabi, United Arab Emirates

2017 ◽  
Vol 11 (4) ◽  
pp. 551-572 ◽  
Author(s):  
Nada Hammad ◽  
Syed Zamberi Ahmad ◽  
Avraam Papastathopoulos
Keyword(s):  
United Arab Emirates ◽  
Social Exchange ◽  
Structural Equation ◽  
Social Exchange Theory ◽  
Cultural Influences ◽  
Abu Dhabi ◽  
Equation Modeling ◽  
Content Type ◽  
The Social ◽  
The Impact

Purpose This paper aims to investigate residents’ perceptions of tourism’s impact on their support for tourism development in Abu Dhabi, United Arab Emirates (UAE). Design/methodology/approach Data were collected using self-administered questionnaires from Abu Dhabi residents (n = 407), who represented 30 nationalities residing in the emirate. Based on social exchange theory, structural equation modeling was used to test hypotheses. Findings Results suggest that Abu Dhabi residents perceive the impacts of tourism positively and are more sensitive to the environmental and economic influences of tourism than the social and cultural influences. Research limitations/implications This study was limited to Abu Dhabi residents; findings cannot be generalized to other emirates in the UAE, or other countries. Originality/value This study adds value to extant tourism literature by investigating residents’ perceptions of the influence of tourism in one of the richest cities worldwide, which aspires to be one of the fastest growing tourism destinations in the Middle East.

Studies on analogs of DAMASCENOLIDETM: Part 4. Synthesis and odor evaluation of sulfur-containing analogs of DAMASCENOLIDETM

2021 ◽  
Author(s):  
Yamato Miyazawa ◽  
Kenji Kawaguchi ◽  
Ryo Katsuta ◽  
Tomoo Nukada ◽  
Ken Ishigami
Keyword(s):  
Sulfur Atom ◽  
Development Project ◽  
Aroma Compounds ◽  
Odor Intensity ◽  
Aroma Compound ◽  
Odor Evaluation ◽  
Damask Rose ◽  
Sulfur Containing ◽  
Sulfur Containing Compounds

ABSTRACT DAMASCENOLIDETM [1, 4-(4-methylpent-3-en-1-yl)furan-2(5H)-one], which is isolated from damask rose, is a useful aroma compound with a citrus-like odor. We have previously reported on the synthesis and odor properties of 34 analogs of 1 as part of our new aroma compound development project. In order to develop better aroma compounds and to gather more information on structure-odor relationships, six novel sulfur-containing analogs of 1 were synthesized. Odor evaluation revealed that their odors differed significantly from those of the corresponding sulfur-free compounds. The introduction of a sulfur atom does not necessarily result in a sulfur-like odor. In particular, the 2(5H)-thiophenone analogs gave waxy, oily and lactone-like odors that are uncharacteristic of sulfur-containing compounds. In many synthesized analogs, the introduction of a sulfur atom led to an increase in odor intensity, as expected.

scholarly journals A priori checking of the light-response and data quality before extended data collection in pump–probe photocrystallography experiments

2017 ◽  
Vol 73 (1) ◽  
pp. 23-26 ◽  
Author(s):  
Philip Coppens ◽  
Anna Makal ◽  
Bertrand Fournier ◽  
Katarzyna N. Jarzembska ◽  
Radosław Kamiński ◽  
...  
Keyword(s):  
Data Collection ◽  
Light Exposure ◽  
A Priori ◽  
Light Response ◽  
Response Ratio ◽  
Full Data ◽  
Pump Probe ◽  
Ratio Correlation ◽  
Induced Signal

In picosecond and slower pump–probe diffraction experiments, collection of response–ratio correlation sets prior to full data collection provides an invaluable confirmation of the existence of a light-induced signal prior to full data collection. If a response to light exposure is observed, the quality of the data being collected can be assessed. A number of such correlation plots both for synchrotron and in-house pump–probe data collection are presented.

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