The Primary productivity and physiology of Ceratophllum demersum. II. Micro primary productivity, pH, and the P/R ratio

1969 ◽  
Vol 20 (2) ◽  
pp. 127 ◽  
Author(s):  
JL Carr
Keyword(s):  
Carbon Dioxide ◽  
Primary Productivity ◽  
Photosynthetic Activity ◽  
Dry Weight ◽  
Day Length ◽  
Chromatic Adaptation ◽  
Ceratophyllum Demersum ◽  
Gross Photosynthesis ◽  
Light Production ◽  
R Ratio

Photosynthesis in Ceratophyllum demersum has been measured in a Warburg respirometer containing a diethanolamine carbon dioxide buffer. Except in May, the photosynthetic activity of leaves is always greater than the buds. Production in the leaves rises from the minimum to the maximum during the period from May to October (winter to spring), probably as a response to increasing day length, while that in the buds remains practically constant throughout the year. With the onset of warmer temperatures in summer, vegetative growth declines. It is concluded that turions of Ceratophyllum are resistant not to cold but to heat and high light intensities of summer. Leaf photosynthesis occurs within a temperature range of 10-30�c and reaches a maximum at 20°C. The extracted chlorophyll content is greatest in plants collected from the surface of the lake and the ratio of chlorophyll a to chlorophyll b reaches a peak at 5 m depth. In Ceratophyllum it is suggested that the phenomenon of chromatic adaptation is occurring, and it is concluded that Ceratophyllum is a shade plant, being adapted to the quantity as well as the quality of light. Production in the leaves is depressed on the surface of the water and is greatest between 2.5 and 5.0 m depth. Also it is suggested that the compensation point for Ceratophyllum in Lake Ohakuri cannot be at a depth of much greater than 8 metres. The photosynthetic activity expressed on a dry weight basis is the greatest in the first mature leaves (6 cm behind the apex) and becomes progressively lower in the buds, leaves (1 ft behind the apex), and the stems. Furthermore, the rate of gross photosynthesis in leaves, buds, or stems exceeds the rate of respiration at all months of the year. Respiration in the dark is greater in the presence of carbon dioxide than in its absence. It is also greater in the dark than in the light. The rate of photosynthesis in Ceratophyllum is greatest at pH 5.0. From this, it is concluded that photosynthesis takes place at the greatest rate in a medium containing free CO2 rather than the bicarbonate ion. With only bicarbonate ion carbon dioxide present photosynthesis will still take place, although it is at a much lower rate.

The primary productivity and physiology of Ceratophyllum demersum. I. Gross macro primary productivity

1969 ◽  
Vol 20 (2) ◽  
pp. 115 ◽  
Author(s):  
JL Carr
Keyword(s):  
Water Flow ◽  
Primary Productivity ◽  
Red Light ◽  
Day Length ◽  
Ceratophyllum Demersum ◽  
Water Flows ◽  
Wet Weight ◽  
Number Of Leaves ◽  
Optimum Production ◽  
Laboratory Stream

An artificial laboratory stream was used to study production in Ceratophyllum demersum under various conditions of light intensity, light quality, day length, and water flow. An incandescent illumination of 1500 f.c. over a 12 hr day length gave optimum production. Moderate amounts of red light gave the greatest increase in wet weight but full red light was inhibitory. Blue light, rather than white light, controlled internode length, but small amounts of red light did not cause any inhibition of this internode lengthening. Production appeared to increase with water flows (current) up to 0.54 cm/sec, but this could have been due to temperature effects. Bud formation was arrested in the slowest water flow tested, viz. 0.46 cm/sec. This suggests that vegetative propagation is retarded by slow water flows. Neither length nor the number of leaves per node showed any response to current or temperature.

scholarly journals Experimental researches on vegetable assimilation and respiration.—XV. The development of photosynthetic activity during germination of different types of seeds

1922 ◽  
Vol 94 (656) ◽  
pp. 12-19 ◽  
Keyword(s):  
Carbon Dioxide ◽  
Photosynthetic Activity ◽  
Dry Weight ◽  
Natural Conditions ◽  
Full Activity ◽  
Mature Leaves ◽  
Different Types ◽  
Experimental Researches ◽  
Further Development ◽  
Growth Experiments

In a previous paper (2) the writer has shown that the photosynthetie activity of the seedling leaves of Phaseolus vulgaris , Vida Faba and Arena sativa is zero or very small for some time after their first appearance, and that oven when further development of chlorophyll is inhibited the activity increases from day to day. Although the photosynthetic activity was measured under such conditions that carbon dioxide was not limiting the rate of assimilation, yet an investigation of the results of growth experiments (3) indicates that under natural conditions of carbon dioxide supply the assimilation of the seedling leaves of maize is very much smaller than that of mature leaves. Tables I, which contains results of experiments carried out by the writer on maize, and la, a collection of scattered results from Willstatter’s work (8), show that some considerable lapse of time is necessary before the seedling leaves of maize attain their full activity, whether light or temperature be limiting; in Willstatter’s experiments temperature was limiting. Experiments recorded by Brenchley (1) show that in the case of Pisum sativum it is some time before the seedling attains a dry weight equal to that of the seed. In the case of Helianthus , however, the evidence from growth experiments (4) indicates that in this plant the seedling leaves, here the cotyledons, assimilate quite actively as soon as they appear above ground, or that at most hardly a day elapses before they reach their full activity. This evidence from growth experiments suggested an investigation of the case of Helianthus on the same lines as that of Phaseolus described in the previous paper. The results of the experiments are recorded in Table II. The same method and apparatus was used as in the previous case (2).

Effects of carbon dioxide on Pharbitis, Xanthium, and Silene in short days

1974 ◽  
Vol 52 (6) ◽  
pp. 1283-1291 ◽  
Author(s):  
A. N. Purohit ◽  
E. B. Tregunna
Keyword(s):  
Carbon Dioxide ◽  
Carbon Dioxide Concentration ◽  
Dry Weight ◽  
Morphological Characters ◽  
Photoperiodic Response ◽  
Pharbitis Nil ◽  
Light Sources ◽  
Short Day ◽  
Unit Leaf ◽  
Silene Armeria

The flowering response and other morphological characters of Pharbitis nil, Xanthium pennsylvanicum, and Silene armeria were studied in environments with different levels of carbon dioxide and oxygen under short-day conditions. Different light sources and intensities were also tested. Irrespective of the light source and intensity used, higher levels of carbon dioxide delayed or inhibited flowering as well as other morphological characters of the short-day plants but induced flowering in the long-day plant. Dry weight per unit leaf area as well as total chlorophyll increased with carbon dioxide concentration. The results are discussed in relation to some other recent reports, and it is proposed that large variations in photosynthetic rates of plants probably alter their photoperiodic response.

Characteristics of the canopy, root system and grain yield of a crop of Lupinus angustifolius cv. Unicrop

1975 ◽  
Vol 26 (3) ◽  
pp. 497 ◽  
Author(s):  
EAN Greenwood ◽  
P Farrington ◽  
JD Beresford
Keyword(s):  
Carbon Dioxide ◽  
Grain Yield ◽  
Leaf Area ◽  
Time Course ◽  
Dry Weight ◽  
Grain Filling ◽  
Main Axis ◽  
Carbon Dioxide Exchange ◽  
Area Index ◽  
Plant Parts

The time course of development of a lupin crop was studied at Bakers Hill, Western Australia. The aim was to gain insight into the crop factors influencing yield. Weekly measurements were made of numbers and weights of plant parts, and profiles of roots, leaf area and light interception. A profile of carbon dioxide in the crop atmosphere was taken at the time of maximum leaf area, and the net carbon dioxide exchange (NCE) of pods was estimated for three successive weeks. The crop took 10 weeks to attain a leaf area index (LAI) of 1 and a further 9 weeks to reach a maximum LAI of 3.75, at which time only 33% of daylight reached the pods on the main axis. Once the maximum LAI was attained at week 19, leaf fall accelerated and rapid grain filling commenced almost simultaneously on all of the three orders of axes which had formed pods. Measurements of NCE between pods on the main axis and the air suggest that the assimilation of external carbon dioxide by the pods contributed little to grain filling. Grain dry weight was 2100 kg ha-1 of which 30%, 60% and 10% came from the main axis, first and second order apical axes respectively. Only 23% of the flowers set pods and this constitutes an important physiological limitation to grain yield.

scholarly journals Phytodepuration of Nitrate Contaminated Water Using Four Different Tree Species

Plants ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 515
Author(s):  
Luca Regni ◽  
Maria Luce Bartucca ◽  
Euro Pannacci ◽  
Francesco Tei ◽  
Daniele Del Buono ◽  
...  
Keyword(s):  
Tree Species ◽  
Photosynthetic Activity ◽  
Dry Weight ◽  
Contaminated Water ◽  
Buffer Strips ◽  
Sambucus Nigra ◽  
Salix Alba ◽  
Global Issue ◽  
Corylus Avellana L ◽  
Agricultural Areas

Water pollution by excessive amounts of nitrate (NO3−) has become a global issue. Technologies to clean up nitrate-contaminated water bodies include phytoremediation. In this context, this research aimed to evaluate four tree species (Salix alba L., Populus alba L., Corylus avellana L. and Sambucus nigra L.) to remediate nitrate-contaminated waters (100 and 300 mg L−1). Some physiological parameters showed that S. alba L. and P. alba L. increased particularly photosynthetic activity, chlorophyll content, dry weight, and transpired water, following the treatments with the above NO3− concentrations. Furthermore, these species were more efficient than the others studied in the phytodepuration of water contaminated by the two NO3− levels. In particular, within 15 days of treatment, S. alba L. and P. alba L. removed nitrate quantities ranging from 39 to 78%. Differently, C. avellana L. and S. nigra L. did not show particular responses regarding the physiological traits studied. Nonetheless, these species removed up to 30% of nitrate from water. In conclusion, these data provide exciting indications on the chance of using S. alba L. and P. alba L. to populate buffer strips to avoid NO3− environmental dispersion in agricultural areas.

scholarly journals Carbon dioxide fluxes over an ancient broadleaved deciduous woodland in southern England

2011 ◽  
Vol 8 (6) ◽  
pp. 1595-1613 ◽  
Author(s):  
M. V. Thomas ◽  
Y. Malhi ◽  
K. M. Fenn ◽  
J. B. Fisher ◽  
M. D. Morecroft ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Primary Productivity ◽  
Management Practices ◽  
Net Primary Productivity ◽  
Deciduous Forest ◽  
Carbon Sink ◽  
Ecosystem Respiration ◽  
Flux Chamber ◽  
Southern England ◽  
Temperate Deciduous

Abstract. We present results from a study of canopy-atmosphere fluxes of carbon dioxide from 2007 to 2009 above a site in Wytham Woods, an ancient temperate broadleaved deciduous forest in southern England. Gap-filled net ecosystem exchange (NEE) data were partitioned into gross primary productivity (GPP) and ecosystem respiration (Re) and analysed on daily, monthly and annual timescales. Over the continuous 24 month study period annual GPP was estimated to be 21.1 Mg C ha−1 yr−1 and Re to be 19.8 Mg C ha−1 yr−1; net ecosystem productivity (NEP) was 1.2 Mg C ha−1 yr−1. These estimates were compared with independent bottom-up estimates derived from net primary productivity (NPP) and flux chamber measurements recorded at a plot within the flux footprint in 2008 (GPP = 26.5 ± 6.8 Mg C ha−1 yr−1, Re = 24.8 ± 6.8 Mg C ha−1 yr−1, biomass increment = ~1.7 Mg C ha−1 yr−1). Over the two years the difference in seasonal NEP was predominantly caused by changes in ecosystem respiration, whereas GPP remained similar for equivalent months in different years. Although solar radiation was the largest influence on daily values of CO2 fluxes (R2 = 0.53 for the summer months for a linear regression), variation in Re appeared to be driven by temperature. Our findings suggest that this ancient woodland site is currently a substantial sink for carbon, resulting from continued growth that is probably a legacy of past management practices abandoned over 40 years ago. Our GPP and Re values are generally higher than other broadleaved temperate deciduous woodlands and may represent the influence of the UK's maritime climate, or the particular species composition of this site. The carbon sink value of Wytham Woods supports the protection and management of temperate deciduous woodlands (including those managed for conservation rather than silvicultural objectives) as a strategy to mitigate atmospheric carbon dioxide increases.

scholarly journals Predicting photosynthesis and transpiration responses to ozone: decoupling modeled photosynthesis and stomatal conductance

2012 ◽  
Vol 9 (8) ◽  
pp. 3113-3130 ◽  
Author(s):  
D. Lombardozzi ◽  
S. Levis ◽  
G. Bonan ◽  
J. P. Sparks
Keyword(s):  
Carbon Dioxide ◽  
Stomatal Conductance ◽  
Primary Productivity ◽  
Environmental Conditions ◽  
Water Exchange ◽  
Global Scale ◽  
Community Land Model ◽  
Climate Regulation ◽  
The Tropics ◽  
Tulip Poplar

Abstract. Plants exchange greenhouse gases carbon dioxide and water with the atmosphere through the processes of photosynthesis and transpiration, making them essential in climate regulation. Carbon dioxide and water exchange are typically coupled through the control of stomatal conductance, and the parameterization in many models often predict conductance based on photosynthesis values. Some environmental conditions, like exposure to high ozone (O3) concentrations, alter photosynthesis independent of stomatal conductance, so models that couple these processes cannot accurately predict both. The goals of this study were to test direct and indirect photosynthesis and stomatal conductance modifications based on O3 damage to tulip poplar (Liriodendron tulipifera) in a coupled Farquhar/Ball-Berry model. The same modifications were then tested in the Community Land Model (CLM) to determine the impacts on gross primary productivity (GPP) and transpiration at a constant O3 concentration of 100 parts per billion (ppb). Modifying the Vcmax parameter and directly modifying stomatal conductance best predicts photosynthesis and stomatal conductance responses to chronic O3 over a range of environmental conditions. On a global scale, directly modifying conductance reduces the effect of O3 on both transpiration and GPP compared to indirectly modifying conductance, particularly in the tropics. The results of this study suggest that independently modifying stomatal conductance can improve the ability of models to predict hydrologic cycling, and therefore improve future climate predictions.

THE CONVERSION OF FAT TO CARBOHYDRATE DURING EMBRYONATION OF ASCARIS EGGS

1957 ◽  
Vol 35 (1) ◽  
pp. 511-525 ◽  
Author(s):  
Richard F. Passey ◽  
Donald Fairbairn
Keyword(s):  
Carbon Dioxide ◽  
Fatty Acids ◽  
Oxygen Consumption ◽  
Direct Evidence ◽  
Dry Weight ◽  
Phosphorus Compounds ◽  
Complete Combustion ◽  
Nitrogenous Compounds

While ascaris eggs developed to the vermiform stage (10 days) both lipids and carbohydrates (glycogen and trehalose) decreased in amount. During the next 15 days, in which the embryo became infective, lipids continued to decrease, but at a greater rate, whereas carbohydrate was completely resynthesized. Examination of the possible sources of the required carbon revealed that protein, non-protein nitrogenous compounds, phosphorus compounds, metabolic acids, glycerol, and volatile acids occurring in the triglycerides were not adequate and that carbon dioxide was not extensively fixed. Direct evidence for the conversion of triglyceride acids to carbohydrate was furnished by the increase in lipid-free dry weight, which corresponded closely with the increase in carbohydrate. Moreover, the amount of lipid carbon which disappeared was equal to the sum of the carbon dioxide and carbohydrate carbon which appeared, and oxygen consumption was insufficient to account for the complete combustion of lipid carbon. It was concluded that the carbon of partially oxidized fragments of fatty acids, possibly acetylcoenzyme A, was incorporated into glycogen and trehalose, and hence that ascaris eggs in this stage of their development were able to bring about a net conversion of fat to carbohydrate.

scholarly journals Growth and Ginsenosides Content of Ginseng Sprouts According to LED-Based Light Quality Changes

Agronomy ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1979
Author(s):  
Yoon-Jeong Kim ◽  
Thi Kim Loan Nguyen ◽  
Myung-Min Oh
Keyword(s):  
Photosynthetic Rate ◽  
Dry Weight ◽  
Fresh Weight ◽  
Light Spectra ◽  
Fluorescent Lamps ◽  
Total Saponin ◽  
R Ratio ◽  
Saponin Content ◽  
One Year ◽  
Total Fresh Weight

This study investigated growth and ginsenosides content of ginseng sprouts under various light spectra. One-year-old ginseng seedlings were cultivated under various light treatments including: monochromatic (red (R), green (G), and blue (B)), various RB and RGB combinations, white (fluorescent lamps (FL) and natural white (NW)), and supplemental far red (FR). R and high R ratio increased growth characteristics of ginseng sprouts (excepted for root dry weight). The replacement of G for B in RGB group and W group did not increase the growth, and supplemental FR increased shoot and root fresh weights, total fresh weight, and leaf area. R had 1.5 times higher photosynthetic rate compared to B and G, and R8G1B1 and R9G1B0 showed the highest values in RGB group; whereas the RB, W, and FR groups did not enhance photosynthetic rate. B and high B ratio increased shoot saponin and ginsenosides, total saponin and ginsenosides contents. Total saponin content in shoot was 4.4 times higher than that in root. The supplemental FR enhanced both total saponin and ginsenosides contents. In conclusion, NW + FR showed the highest total fresh weight, saponin and ginsenosides contents among all treatments, suggesting that supplementation of FR has a positive effect on ginseng sprouts grown in plant factories.

Anaerobic Benzene Biodegradation Linked to Nitrate Reduction

1999 ◽  
Vol 65 (2) ◽  
pp. 529-533 ◽  
Author(s):  
Siobhan M. Burland ◽  
Elizabeth A. Edwards
Keyword(s):  
Carbon Dioxide ◽  
Cell Growth ◽  
Nitrate Reduction ◽  
Dry Weight ◽  
Benzene Oxidation ◽  
Constant Ratio ◽  
Nitrogen Gas ◽  
Benzene Degradation ◽  
Enrichment Cultures

ABSTRACT Benzene oxidation to carbon dioxide linked to nitrate reduction was observed in enrichment cultures developed from soil and groundwater microcosms. Benzene biodegradation occurred concurrently with nitrate reduction at a constant ratio of 10 mol of nitrate consumed per mol of benzene degraded. Benzene biodegradation linked to nitrate reduction was associated with cell growth; however, the yield, 8.8 g (dry weight) of cells per mol of benzene, was less than 15% of the predicted yield for benzene biodegradation linked to nitrate reduction. In experiments performed with [14C]benzene, approximately 92 to 95% of the label was recovered in 14CO2, while the remaining 5 to 8% was incorporated into the nonvolatile fraction (presumably biomass), which is consistent with the low measured yield. In benzene-degrading cultures, nitrite accumulated stoichiometrically as nitrate was reduced and then was slowly reduced to nitrogen gas. When nitrate was depleted and only nitrite remained, the rate of benzene degradation decreased to almost zero. Based on electron balances, benzene biodegradation appears to be coupled more tightly to nitrate reduction to nitrite than to further reduction of nitrite to nitrogen gas.

Sign in / Sign up

Export Citation Format

Share Document