THE RELATIONSHIP BETWEEN CHLOROPHYLL CONTENT AND RATE OF PHOTOSYNTHESIS IN SOYBEANS

1977 ◽  
Vol 57 (1) ◽  
pp. 1-5 ◽  
Author(s):  
B. R. BUTTERY ◽  
R. I. BUZZELL
Keyword(s):  
Linear Regression ◽  
Chlorophyll Content ◽  
Photosynthetic Rate ◽  
Regression Line ◽  
Quadratic Equation ◽  
Chlorophyll Contents ◽  
Rate Of Photosynthesis ◽  
Highly Correlated ◽  
The Relationship ◽  
Selection Of

Photosynthetic rate of soybeans (on a leaf area basis, PA) estimated from the incorporation of 14CO2 under field conditions was highly correlated with chlorophyll content of the side leaflets of the same leaves. Among a collection of 48 cultivars, the linear regression of PA on chlorophyll content accounted for 44% of the variation, whereas with a selection of genotypes with various mutant chlorophyll genes, the regression accounted for 81%. When the data for the two tests were re-calculated relative to the check cv. Altona, a quadratic equation between PA and chlorophyll accounted for nearly 90% of the variation. When photosynthetic rate was expressed on a unit chlorophyll basis (Pc), no significant differences among lines were established in the cultivar test. In the mutants test, significant differences in Pc were established with higher values of Pc associated with lower chlorophyll contents; a linear regression accounted for 45% of the variation. Transformation of the data from both experiments relative to Altona allowed the fitting of a common regression line (quadratic) which accounted for 63% of the variation. We suggest that initial screening of progenies in a breeding program for high photosynthetic rate could be done by measuring chlorophyll content.

scholarly journals Use Diluted Tomato Petiole Sap for K Measurement with the Cardy Meter

HortScience ◽  
2004 ◽  
Vol 39 (4) ◽  
pp. 795D-795
Author(s):  
Henry G. Taber* ◽  
Vince Lawson ◽  
Diane Shogren
Keyword(s):  
Linear Regression ◽  
Regression Line ◽  
Deionized Water ◽  
Moisture Loss ◽  
Linear Regression Equation ◽  
Rate Experiment ◽  
K Concentration ◽  
Highly Correlated ◽  
The Relationship ◽  
Petiole Sap

Undiluted tomato petiole sap from a variety by K rate experiment (48 treatment rep combinations) was used to measure K concentration via the battery operated portable Cardy meter and ICP laboratory instrumentation. Three sample 1998 dates, 16 July., 21 Aug., and 8 Sept., resulted in K sap readings by ICP of 3917, 2612, and 2297 ppm, respectively. At sap levels below 3000 ppm the linear Cardy:ICP correlation was r = 0.04, but above 3000 ppm only 0.53. From 3500 to 5000 ppm K the Cardy meter under estimated actual sap K by 200 to 900 ppm. For the years 1999 and 2001, tomato petiole sap at each sample date (4) was diluted 1:1 with deionized water. The linear regression equation describing the relationship between ICP and Cardy meter measurements was: Cardy K ppm = 0.733 * ICP + 685 (r = 0.92, n = 190). The Cardy meter error over the 2000 to 5000 ppm K range was 8 to 12%. Petiole sap K, measured by either Cardy or ICP, was highly correlated to whole leaf K concentration both years. But even though the slope of the regression lines was similar the intercepts were significantly different (P≤.01). The significant 0.32% K difference in whole leaf between years precluded the development of a common regression line to predict whole leaf K from Cardy petiole sap determinations. The Cardy meter can be reliably used for tomato petiole K determination provided the sap is diluted and the usual handling precautions are taken to prevent petiole moisture loss.

scholarly journals Chlorophyll as an indicator of green tea quality

2014 ◽  
Vol 83 (10) ◽  
pp. S103-S109 ◽  
Author(s):  
Martina Ošťádalová ◽  
Bohuslava Tremlová ◽  
Jana Pokorná ◽  
Martin Král
Keyword(s):  
Chlorophyll Content ◽  
Green Tea ◽  
Storage Time ◽  
Chlorophyll Concentration ◽  
Storage Period ◽  
Storage Conditions ◽  
Qualitative Variable ◽  
Chlorophyll Contents ◽  
Tea Quality ◽  
The Relationship

The objective of this work was to study the changes in chlorophyll contents in green teas stored under different conditions and to suggest the most suitable way and length of green tea storage. A secondary aim was to evaluate the possibility of using the chlorophyll content as an indicator of tea freshness. Samples for analysis were obtained from a range of tea-growing regions. Chlorophyll contents were measured using UV-vis spectrophotometry. Chlorophyll absorbance was measured at 642.5 and 660 nm. Prior to storage, chlorophyll concentration in teas ranged from 1.12 to 1.89 mg per 1 g of tea, which corresponded to data given by other authors. Storage was found to lead to a decline in chlorophyll concentration. From the 6th month of storage onwards, a significant decrease (P < 0.05) was observed in all samples, irrespective of storage conditions. Based on the findings of this study, original and metal packaging can be considered the most chlorophyll-friendly. On the other hand, glass and paper packaging stored in direct daylight were found to have the strongest impact on chlorophyll concentration. Overall, it can be concluded that the storage time can have a strong influence on oolong green tea colour as an important qualitative variable. Thus, the shelf-life of tea should be shorter than the 12 months claimed by most manufacturers. Once the relationship between changes in chlorophyll concentration and length of the storage period had been established, the chlorophyll content was suggested as an indicator of the storage time (freshness) of a tea substance.

An integrating sphere for the rapid nondestructive estimation of whole-plant chlorophyll content

1983 ◽  
Vol 61 (12) ◽  
pp. 3072-3079 ◽  
Author(s):  
F. D. H. Macdowall
Keyword(s):  
Chlorophyll Content ◽  
Scattered Light ◽  
Red Light ◽  
Quadratic Equation ◽  
Coefficient Of Determination ◽  
Integrating Sphere ◽  
Selective Absorption ◽  
Chlorophyll Contents ◽  
Whole Plant ◽  
Before And After

The chlorophyll contents of seedlings of several plant species were estimated from the voltages emitted by a photocell before and after the insertion of the shoot systems into a 61-cm integrating sphere. Red light of 675-nm wavelength was projected into the sphere for selective absorption by chlorophyll, as shown by an absorption spectrum, and the readout was calibrated against total extracted chlorophyll. The species and thus the morphology of the plant were of no significant consequence. The absorbance by chlorophyll in plants obeyed Beer's law up to a content of about 60 mg chlorophyll; however, over a wider range the calibration curve for absorbance, like that for absorptance, was best fitted by a quadratic equation which gave a coefficient of determination of 98% and a standard error of estimate for chlorophyll of 2 mg. A band width of 4 mg chlorophyll was obtained between the 95% confidence limits for chlorophyll as a function of absorbance of plants that contained less than 20 mg chlorophyll. A similar 4-mg confidence belt for chlorophyll on absorptance applied through the range of about 5 to 45 mg chlorophyll in plants. A usable linear relation was obtained between chlorophyll content and the ratio of the scattered light not absorbed at 750 nm to that at 675 nm.

scholarly journals Estimation of chlorophyll concentration in maize using spectral reflectance

2015 ◽  
Vol XL-7/W3 ◽  
pp. 65-71 ◽  
Author(s):  
L. J. Martinez ◽  
A. Ramos
Keyword(s):  
Chlorophyll Content ◽  
Chlorophyll Concentration ◽  
Spectral Indices ◽  
Strong Correlations ◽  
Spectral Measurements ◽  
Maize Crop ◽  
Chlorophyll Contents ◽  
N Rates ◽  
Reflectance Indices ◽  
The Relationship

The objective of this research was to identify the relationship between chlorophyll contents and spectral measurements in a maize crop. Spectral measurements were taken and the chlorophyll content was determined in leaf samples in a field experiment with different N rates. Analysis of variance showed differences in the chlorophyll content and spectral indices for the treatments and strong correlations between some reflectance indices and chlorophyll content. Due to a relationship between the N and chlorophyll contents, the results proved to be important for making decisions related to the nitrogen supply for crops, which is crucial in agriculture.

The relationship between live measurements and edible meat in Merino wethers

1964 ◽  
Vol 15 (3) ◽  
pp. 446 ◽  
Author(s):  
GM Tallis ◽  
HN Turner ◽  
GH Brown
Keyword(s):  
Correlation Analysis ◽  
Fat Content ◽  
Carcass Weight ◽  
Meat Production ◽  
Multiple Correlation ◽  
Multiple Correlation Analysis ◽  
Highly Correlated ◽  
The Relationship ◽  
Selection Of

Seventy-five Merino wethers of a medium Peppin strain were slaughtered at 7 months of age after a series of live measurements had been made, weights then being taken of carcass and of edible meat after boning out. Fat content was insufficient for trimming, and bone weight was obtained by difference. Weight of edible meat was highly correlated (0.95) with liveweight before slaughter, and the inclusion of any other measurement in a multiple correlation analysis failed to raise this value. Variation in bone weight contributed only 25% of the variation in carcass weight, and the ratio of meat to bone was positively correlated (0.54) with liveweight before slaughter. If total amount of edible meat is accepted as the criterion for meat production, liveweight before slaughter was a satisfactory predictor for these sheep. It is suggested that simplification of criteria along these lines is desirable to aid in the selection of sheep for meat production, though more work is required on sheep of other ages and other breeds.

Relationship between visual colour rating and chlorophyll content, photosynthetic rate, and some growth characteristics in couchgrass (Cynodonspp. L.)

1983 ◽  
Vol 100 (1) ◽  
pp. 221-225 ◽  
Author(s):  
M. S. Rahman
Keyword(s):  
Leaf Area ◽  
Chlorophyll Content ◽  
Photosynthetic Rate ◽  
Unit Area ◽  
Dark Respiration ◽  
Dry Weight ◽  
Chlorophyll Contents ◽  
Respiration Rates ◽  
Unit Leaf ◽  
Visual Colour

SUMMARYChlorophyll contents per unit leaf area and unit dry weight, chlorophylla:bratio, visual colour rating, specific leaf area, and leaf fresh weight: dry weight ratios were estimated for 12 couch (bermudagrass) varieties (Cynodonspp. L.) in winter (July) and spring (October). Net photosynthetic and dark respiration rates were estimated in winter only.The chlorophyll contents per unit leaf area were higher in all varieties in spring than in winter, but per unit weight were more variable. The varieties differed substantially in the net photosynthetic and dark respiration rates. The specific leaf areas were greater in winter than in spring in five varieties: in others it changed little. The fresh: dry weight ratios of the leaves were almost constant between varieties in the spring but varied greatly during the winter. Visual colour ratings were well correlated with chlorophyll contents per unit area but not with weight. The net photosynthetic rate was closely correlated with chlorophyll content (per unit area) but not so closely with colour rating.

The Relationship between the Visual Analog Pain Intensity and Pain Relief Scale Changes during Analgesic Drug Studies in Chronic Pain Patients 

1999 ◽  
Vol 91 (1) ◽  
pp. 34-41 ◽  
Author(s):  
Martin S. Angst ◽  
William G. Brose ◽  
John B. Dyck
Keyword(s):  
Pain Relief ◽  
Linear Regression ◽  
Pain Intensity ◽  
Regression Line ◽  
Drug Action ◽  
Analgesic Drug ◽  
Before And After ◽  
The Relationship ◽  
Drug Studies ◽  
Pain Patients

Background Most analgesic drug studies in humans quantify drug action based on verbal reports of pain intensity and pain relief. Although measures of pain intensity and pain relief show a good overall correlation, it is not known if they relate to each other consistently over time Such consistency is necessary if both measures are used to depict analgesic drug action versus time. This study examined in chronic pain patients if the relationship between visual analog pain intensity and pain relief scores was consistent during two analgesic drug studies. Methods Data from two independently performed analgesic drug studies were analyzed using linear regression. Data were split into pain intensity and pain relief scores recorded before and after patients' experience of maximum analgesia (&gt;90% of maximum pain relief). The slopes of the linear regression line depicting pain intensity versus pain relief scores before and after maximum analgesia were statistically compared. Results The slope of the linear regression line before and after maximum analgesia was significantly different in both drug studies (nonoverlapping 95% confidence intervals), -2.16+/-0.57 versus -1.05+/-0.10 and -1.47+/-0.26 versus -1.09+/-0.07, respectively. These results are compatible with the observation that patients indicating the same pain intensity before and after maximum analgesia reported a different magnitude of pain relief. Conclusions The relationship between visual analog pain intensity and pain relief scores changed systematically during both analgesic drug studies. The authors hypothesize that patients' interpretation of the pain relief scale had changed during the studies and therefore suggest using the pain intensity scale to quantify analgesic drug action over time.

Photosynthetic ecology of normal and variegated Aegopodium podagraria

1973 ◽  
Vol 51 (9) ◽  
pp. 1589-1592 ◽  
Author(s):  
Ernest Small
Keyword(s):  
Competitive Advantage ◽  
Leaf Area ◽  
Chlorophyll Content ◽  
Photosynthetic Rates ◽  
Chlorophyll Contents ◽  
Full Sunlight ◽  
Area Basis ◽  
Rate Of Photosynthesis ◽  
The Mean ◽  
Two Populations

Aegopodium podagraria, widely cultivated in a variegated form, occasionally gives rise to normal (non-variegated) plants which are comparatively vigorous, exhibiting marked weedy tendencies. Net photosynthetic rates and chlorophyll contents were determined for two populations of normal plants and three populations of variegated plants grown separately under full sunlight, and in shade. None of the populations grown in full sunlight differed significantly from each other in rate of photosynthesis on a leaf area basis, despite the mean 83.5% higher chlorophyll content of normal leaves. However, when grown in shade, on a leaf area basis normal plants averaged 50.1% higher rates of photosynthesis, and 73.5% higher content of chlorophyll, and the leaves were 27.4% heavier than the leaves of variegated plants. These differences apparently are responsible for the competitive advantage of normal plants in the usually shady habitat of A. podagraria.

Study on the Effects of Wastewater Duress on Chlorophyll Content of 4 Species Wetland Plants

2014 ◽  
Vol 1010-1012 ◽  
pp. 809-812
Author(s):  
Min Lu ◽  
Gong Sheng Liu ◽  
Dong He Li ◽  
Wen Feng Kang ◽  
Jie Zhao ◽  
...  
Keyword(s):  
Chlorophyll Content ◽  
Arundo Donax ◽  
Wetland Plants ◽  
Species Selection ◽  
Phragmites Communis ◽  
Treatment Technology ◽  
Chlorophyll Contents ◽  
Typha Orientalis ◽  
Canna Generalis ◽  
Selection Of

The research which is the species selection of constructed wetland plants and the resistance of the plants is the key to ecological wastewater treatment technology. This paper studies the change of chlorophyll content in 4 wetland plants (Phragmites communis, Typha orientalis, Arundo donax and Canna generalis) in different wastewater duress time. The results show: chlorophyll contents in Canna generalis and Arundo donax have less change, and their anti-stress capability are stronger.

scholarly journals Estimating leaf area of prata-type banana plants with lanceolate type leaves

2020 ◽  
Vol 42 (4) ◽  
Author(s):  
Lucas Titonelli Ferreira Donato ◽  
Sérgio Luiz Rodrigues Donato ◽  
Cleiton Fernando Barbosa Brito ◽  
Varley Andrade Fonseca ◽  
Carlos Nick Gomes ◽  
...  
Keyword(s):  
Linear Regression ◽  
Leaf Area ◽  
Pearson Correlation ◽  
Correlation Coefficients ◽  
Regression Equations ◽  
Significance Level ◽  
Backward Elimination ◽  
Leaf Dimensions ◽  
Highly Correlated ◽  
The Relationship

Abstract Models for estimating leaf area of bananas found in the literature are not suitable for lanceolate type leaves occurring at the vegetative stage of ratoon suckers dependent of mother plant. The objective was to determine equations for estimating the leaf area of ‘Prata-Anã’ and ‘BRS Platina’ banana plants with lanceolate type leaves. 212 and 164 lanceolate type leaves having 10 cm-wide lamina or less were collected from ‘Prata-Anã’ and ‘BRS Platina’ banana plants of 90 days of age or less, respectively. Width (W), length (L), width/length ratio (WLR), and scanner-measured leaf area (LAscanner) were determined. Using the backward elimination procedure, simple and multiple linear regression equations were fitted to the relationship between leaf dimensions (W, L and WLR) and LAscanner. To evaluate how precise the equations are in predicting leaf area (LApredicted), Pearson correlation coefficients were calculated between LA and LApredictedscanner. The models highly correlated with LAscanner at 1% of significance level. The models are and LALL() = Prata-Anã = - 0,0133624 + 0,000489859**L - 0,00183182 **W and LALL(Platina) 0,00237026 + 0,004781**W - 0,096802** WLR.

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