Photosynthesis and dark respiration of black spruce cuttings during rooting in response to light and temperature

1993 ◽  
Vol 23 (6) ◽  
pp. 1150-1155 ◽  
Author(s):  
De Yue ◽  
Hank A. Margolis
Keyword(s):  
Black Spruce ◽  
Dark Respiration ◽  
Net Photosynthesis ◽  
Dry Weight ◽  
Experimental Period ◽  
Photon Flux ◽  
Photosynthetic Rates ◽  
Physiological Quality ◽  
Use Efficiency ◽  
Total Dry Weight

Photosynthesis and dark respiration of semihardened black spruce cuttings (Piceamariana (Mill.) B.S.P.) were periodically measured at a range of light intensities at 10, 15, 20, 25, and 30 °C over an 8-week period in rooting chambers and for 4 additional weeks after the cuttings were transferred to a greenhouse. Increases in the total dry weight of the cuttings over the experimental period were due exclusively to increases in root biomass. The light-saturated photosynthetic rates at 20 °C decreased from 3.8 to 2.2 μmol CO2•m−2•s−1 during the 8 weeks in the rooting chamber. At 15 °C, the light-saturated photosynthetic rate was about 2 μmol CO2•m−2•s−1 and no significant change was observed during the experimental period. Maximum photosynthetic rates were generally attained at photosynthetic photon flux densities (PPFD) of 200–300 μmol•m−2•s−1 At the range of PPFD generally used in rooting chambers (0–50 μmol•m−2•s−1), the light use efficiency of cuttings (net photosynthesis per cutting per PPFD) was greatest at 15 °C. Furthermore, the light compensation point was lowest at 15 °C. The effect of light intensity and temperature on the photosynthesis and dark respiration of cuttings was modelled to predict the carbon balance of cuttings under different conditions of PPFD and temperature. This model should be useful in determining an appropriate set of environmental conditions to use inside rooting chambers and thus improve the overall physiological quality of this type of vegetatively propagated planting stock. The modelling approach described in this study could prove useful for the production of other conifer species by rooted cuttings even when it is conducted using other methods of cultivation (e.g., cold-frames or greenhouses).

scholarly journals Effect of fertigation with potassium and nitrogen on gas exchange and biomass accumulation in eggplant1

2017 ◽  
Vol 47 (3) ◽  
pp. 345-352
Author(s):  
Álvaro Henrique Cândido de Souza ◽  
Roberto Rezende ◽  
Marcelo Zolin Lorenzoni ◽  
Fernando André Silva Santos ◽  
André Maller
Keyword(s):  
Stomatal Conductance ◽  
Gas Exchange ◽  
Water Use ◽  
Biomass Accumulation ◽  
Net Photosynthesis ◽  
Dry Weight ◽  
Co2 Concentration ◽  
Internal Co2 ◽  
Use Efficiency ◽  
Total Dry Weight

ABSTRACT Adequate crop fertilization is one of the challenges for agriculture. Measuring gas exchange and biomass accumulation may be used to adjust crop management. The effect of fertigation with potassium (0 kg ha-1, 54 kg ha-1, 108 kg ha-1 and 216 kg ha-1) and nitrogen (0 kg ha-1, 67 kg ha-1, 134 kg ha-1 and 268 kg ha-1) on gas exchange and biomass accumulation in eggplant was assessed under greenhouse conditions. The net photosynthesis, stomatal conductance, transpiration, internal CO2 concentration, instantaneous carboxylation efficiency, water-use efficiency and total dry weight were evaluated. With the exception of K for water-use efficiency and N for internal CO2 concentration, all the other gas exchange parameters were significantly affected by the K and N doses. There was an interaction between N and K doses for net photosynthesis, stomatal conductance, transpiration and instantaneous carboxylation efficiency. The highest values for net photosynthesis, stomatal conductance, transpiration rate, carboxylation instantaneous efficiency and total dry weight were found in the range of 125-185 kg ha-1 of K and 215-268 kg ha-1 of N.

Effect of Soil pH, Soil Water, Light Intensity, and Temperature on Perennial Sowthistle (Sonchus arvensisL.)

Weed Science ◽  
1991 ◽  
Vol 39 (3) ◽  
pp. 376-384 ◽  
Author(s):  
Richard K. Zollinger ◽  
James J. Kells
Keyword(s):  
Soil Moisture ◽  
Light Intensity ◽  
Water Use Efficiency ◽  
Soil Water ◽  
Water Use ◽  
Soil Ph ◽  
Dry Weight ◽  
Photon Flux ◽  
Use Efficiency ◽  
Total Dry Weight

Growth of perennial sowthistle was examined under different levels of soil pH, soil moisture content, light intensity, and temperature. Soil pH ranging from 5.2 to 7.2 had little effect on the number of leaves, rosette diameter, plant height, and number of capitula. However, total dry weight was 30% less in plants grown in soil of pH 5.2 compared to those grown at higher soil pH levels. Perennial sowthistle demonstrated a consistent positive growth response to increasing soil water including saturation. Severe reduction in vegetative and reproductive growth occurred in plants grown in soil below field capacity. Plants grown under full light (1015 μE m−2s−1photosynthetic photon flux density) developed a fourfold increase in the number of capitula per plant and a 50% increase in total dry weight compared to plants grown at 285 μE m−2s−1. Initiation of reproduction was delayed 4 weeks for plants grown at 580 μE m−2s−1and 285 μE m−2s−1. Plants grown under less than full light developed fewer but larger leaves. Plants grown under a day/night temperature of 20/15 C grew more rapidly than those under 30/25 C or 10/5 C. Plants at 30/25 C began to senesce 7 to 8 weeks after planting. Net carbon assimilation, leaf conductance, transpiration, and water use efficiency decreased as soil moisture and light intensity decreased. Plants at 30/25 C had the highest rate of transpiration and the lowest water use efficiency. The observed optimum for perennial sowthistle growth occurred at a soil pH of 6.2 or 7.2, water-saturated soil, high light intensity, and a temperature of 20/15 C, day/night.

Photosynthetic Performance of Two Closely Related Umbilicaria Species in Central Spain: Temperature as a Key Factor

1997 ◽  
Vol 29 (1) ◽  
pp. 67-82 ◽  
Author(s):  
L. G. Sancho ◽  
B. Schroeter ◽  
F. Valladares
Keyword(s):  
Water Content ◽  
Dark Respiration ◽  
Net Photosynthesis ◽  
Dry Weight ◽  
Distribution Patterns ◽  
Photon Flux ◽  
Photosynthetic Response ◽  
Central Spain ◽  
Natural Conditions ◽  
Thallus Water Content

AbstractNet photosynthesis (NP) and dark respiration (DR) of thalli of the lichen species Umbilicaria grisea and U. freyi growing together in the same habitat the Sierra de Guadarrama, central Spain, were measured under controlled conditions in the laboratory and under natural conditions in the field over a range of photosynthetic photon flux densities (PPFD), thallus temperatures and thallus water contents. Laboratory experiments revealed that the photosynthetic response to PPFD at optimum thallus water content is very similar in both species. The light compensation points of NP increased from PPFD of c. 20 µmol m−2 s−1 at 0°C up to c. 100 µmol m−2 s−1 PPFD at 25°C. In both species light saturation was not reached up to 700 µmol m−2 s−1 PPFD except at 0°C. By contrast, the temperature dependence of CO2 gas exchange differed substantially between U. grisea and U. freyi. Both species gave significant rates at 0°C. Optimal temperatures of NP were always higher in U. grisea at various PPFD levels if the samples were kept at optimal thallus water content. NP showed maximal rates at 95% dw in U. grisea and 110% dw in U. freyi respectively. In U. grisea a much stronger depression of NP was observed with only 5% of maximal NP reached at 180% dw. At all PPFD and temperature combinations U. freyi showed higher rates of NP and more negative rates of DR if calculated on a dry weight basis. This was also true under natural conditions at the same site, when U. freyi was always more productive than U. grisea. The differences in the photosynthetic response to temperature between both species correlated well with the different distribution patterns of both species. The possibility of genetic control of the physiological performance of these species and its influence on their distribution patterns and autecology is discussed.

Two physiological races of Tsuga canadensis in Wisconsin

1975 ◽  
Vol 53 (9) ◽  
pp. 940-951 ◽  
Author(s):  
William Eickmeier ◽  
Michael Adams ◽  
Donald Lester
Keyword(s):  
Dark Respiration ◽  
Net Photosynthesis ◽  
Tsuga Canadensis ◽  
Seedling Morphology ◽  
Seed Sources ◽  
Temperature Regimes ◽  
Disjunct Populations ◽  
Use Efficiency ◽  
Osmotic Potentials ◽  
Carbon Dioxide Balance

Population differentiation in Tsuga canadensis (L.) Carr. from Wisconsin was tested by comparing seedlings grown from seed collected within the present range in the northeast and from seed collected in disjunct populations southwest of the present range. The seedlings, established in hydroponic culture, were subjected to two preconditioning temperature regimes and two water stress simulations. Net photosynthesis, dark respiration, and transpiration capacities were measured and internal leaf resistances were calculated.The southwestern Wisconsin population had a more favorable carbon dioxide balance at warmer tissue temperatures, particularly at low irradiance levels, and at higher osmotic potentials, than did the northeastern population, which was better adapted to lower tissue temperatures and lower osmotic potentials. Additional differences between seed sources in seedling morphology, transpiration rate, and water-use efficiency were found. These differences in morphology and physiological responses corresponded to the macroclimates in which these populations were found, southwestern Wisconsin being warmer and drier than the northeastern part of the state.

Productivity of Vegetable Crops in a Region of High Solar Input. III. Carbon Balance of Potato Crops

1974 ◽  
Vol 1 (2) ◽  
pp. 283 ◽  
Author(s):  
PJM Sale
Keyword(s):  
Carbon Balance ◽  
Dark Respiration ◽  
Net Photosynthesis ◽  
Dry Weight ◽  
Gas Analysis ◽  
Co2 Uptake ◽  
Co2 Efflux ◽  
Vegetable Crops ◽  
Weight Changes ◽  
Potato Crops

The carbon balance of potato crops has been studied by measuring canopy net photosynthesis and dark respiration losses with a field assimilation chamber and semi-closed gas analysis system. Results are given for the latter part of growth in both a spring-planted and a summer-planted crop. Net CO2 uptake increased with solar input to reach 35–40mg dm-2 (ground area) h-1 at 400–450 W m-2, but light saturation then occurred and little or no further uptake resulted from increases in solar input up to 1000 W m-2. This supports the previous conclusion that net photosynthesis in the potato is determined by the size of the 'sink' provided by the developing tubers. The imposed experimental variables of reduced solar input (21 and 34% shade) and soil moisture were found not to affect the relation between solar input and CO2 uptake, and the effect of chamber temperature was also very small. Dark respiration rates of the canopy were markedly sensitive to temperature, and also to the solar input prior to measurement. Respiration from the below-ground plant parts accounted for a considerable part of the total plant respiration. In all, 15–20 % of the net assimilation during daylight hours was lost by night respiration. There was little variation in CO2 efflux from uncropped soil during the experiments. Dry weight changes calculated from the gasometric measurements were in accordance with those found from previous growth analysis. * Part II, Aust. J. Agric. Res., 1973, 24, 751–62.

scholarly journals Endophytic Isolates of Cordyceps fumosorosea to Enhance the Growth of Solanum melongena and Reduce the Survival of Whitefly (Bemisia tabaci)

Insects ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 78
Author(s):  
Tingfei Sun ◽  
Zhang Shen ◽  
Mobeen Shaukat ◽  
Cailian Du ◽  
Shaukat Ali
Keyword(s):  
Bemisia Tabaci ◽  
Seed Treatment ◽  
Growth Parameters ◽  
Solanum Melongena ◽  
Dry Weight ◽  
Experimental Period ◽  
Response To Treatment ◽  
Insect Mortality ◽  
Number Of Leaves ◽  
Total Dry Weight

This study reports the effects of seed treatment with Cordyceps fumosorosea on seed germination, growth, colonization of eggplant (Solanum melongena), and growth of Bemisia tabaci (feeding on fungal colonized eggplant leaves). Germination rates of eggplant seeds were similar among different treatments. The growth parameters such as root length, shoot length, and number of leaves) differed significantly after 15, 30, and 60 days of seed treatment. The total dry weight of eggplant in response to treatment with C. fumosorosea isolates increased significantly when compared with the control. Both isolates of C. fumosorosea colonized different plant tissues, although the extent of colonization decreased during the experimental period. The colonization of eggplants by both C. fumosorosea isolates resulted in a significant reduction of B. tabaci incidence. This study possibly provides the first report of increased plant growth and increased insect mortality in eggplants inoculated with C. fumosorosea isolates.

The ecology of Ramalina menziesii. VI. Laboratory responses of net CO2 exchange to moisture, temperature, and light

1987 ◽  
Vol 65 (1) ◽  
pp. 182-191 ◽  
Author(s):  
U. Matthes-Sears ◽  
T. H. Nash III ◽  
D. W. Larson
Keyword(s):  
Dark Respiration ◽  
Net Photosynthesis ◽  
Co2 Exchange ◽  
Response Curves ◽  
Central California ◽  
Photosynthetic Rates ◽  
Chlorophyll Contents ◽  
The Mean ◽  
The Difference ◽  
Thallus Water Content

The response of net CO2 exchange to thallus water content, thallus temperature, and photosynthetically active radiation was measured in the laboratory for two morphologically different forms of Ramalina menziesii collected from a coastal and an inland habitat in central California. Equations describing the response curves are fitted to the data and compared statistically for the two sites during two seasons. Significant differences were present for all responses both in summer and winter but were more pronounced for net photosynthesis than for dark respiration. The main differences between the two forms were in the absolute rates of net photosynthesis; a maximum of 6.2 was measured for the inland form but only 3.6 mg∙g−1∙h−1 for the coastal form. Chlorophyll contents were also different between the two forms, indicating that chlorophyll is the likely cause for the difference in net photosynthetic rates. Net photosynthetic rates were higher at low temperatures during winter than during summer, but otherwise seasonal variations in the gas exchange responses were relatively minor. Both forms of the lichen are light saturated at quantum fluxes greater than 200 μE∙m−2∙s−1. Both show an optimum temperature for maximum CO2 exchange at 25 °C, well above the mean operating temperature of R. menziesii in the field.

Comparison of growth and physiology of layers and naturally established seedlings of black spruce in a boreal cutover in Quebec

1999 ◽  
Vol 29 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Raynald Paquin ◽  
Hank A Margolis ◽  
René Doucet ◽  
Marie R Coyea
Keyword(s):  
Water Potential ◽  
Picea Mariana ◽  
Black Spruce ◽  
Net Photosynthesis ◽  
Growing Season ◽  
Height Growth ◽  
Total Height ◽  
Acclimation Period ◽  
Use Efficiency ◽  
Growth Of Seedlings

Growth and physiology of layers versus naturally established seedlings of boreal black spruce (Picea mariana (Mill.) BSP) were compared 15 years after a cutover in Quebec. During the first 8 years, height growth of seedlings was greater than that of layers, averaging 10.4 and 7.0 cm/year, respectively. For the last 5 years, annual height growth of layers and seedlings did not differ (25 cm/year; p > 0.05). Over the entire 15-year period, total height growth of seedlings (251 cm) was greater than that of layers (220 cm), although total height did not differ (p > 0.05) over the last 6 years. During the 15th growing season, there were no differences (p > 0.05) for predawn shoot water potential, stomatal conductance, net photosynthesis, intercellular to ambient CO2 ratio, water use efficiency, and hydraulic conductance between layers and seedlings. For diurnal shoot water potential, seedlings showed slightly less stress than layers on two of the four sampling dates. Thus, in the first few years following the cutover, the slower growth observed for layers indicated that they had a longer acclimation period following the cutover. Afterwards, similar height growth, total height, and physiological characteristics of the two regeneration types indicated that layers can perform as well as naturally established seedlings.

scholarly journals Photosynthetic responses of three common mosses from continental Antarctica

2005 ◽  
Vol 17 (3) ◽  
pp. 341-352 ◽  
Author(s):  
STEFAN PANNEWITZ ◽  
T.G. ALLAN GREEN ◽  
KADMIEL MAYSEK ◽  
MARK SCHLENSOG ◽  
ROD SEPPELT ◽  
...  
Keyword(s):  
Climate Change ◽  
Water Content ◽  
Dark Respiration ◽  
Temperature Response ◽  
Environmental Parameters ◽  
Net Photosynthesis ◽  
Photon Flux ◽  
Terrestrial Vegetation ◽  
Moss Species ◽  
Victoria Land

Predicting the effects of climate change on Antarctic terrestrial vegetation requires a better knowledge of the ecophysiology of common moss species. In this paper we provide a comprehensive matrix for photosynthesis and major environmental parameters for three dominant Antarctic moss species (Bryum subrotundifolium, B. pseudotriquetrum and Ceratodon purpureus). Using locations in southern Victoria Land, (Granite Harbour, 77°S) and northern Victoria Land (Cape Hallett, 72°S) we determined the responses of net photosynthesis and dark respiration to thallus water content, thallus temperature, photosynthetic photon flux densities and CO2 concentration over several summer seasons. The studies also included microclimate recordings at all sites where the research was carried out in field laboratories. Plant temperature was influenced predominantly by the water regime at the site with dry mosses being warmer. Optimal temperatures for net photosynthesis were 13.7°C, 12.0°C and 6.6°C for B. subrotundifolium, B. pseudotriquetrum and C. purpureus, respectively and fall within the known range for Antarctic mosses. Maximal net photosynthesis at 10°C ranked as B. subrotundifolium > B. pseudotriquetrum > C. purpureus. Net photosynthesis was strongly depressed at subzero temperatures but was substantial at 0°C. Net photosynthesis of the mosses was not saturated by light at optimal water content and thallus temperature. Response of net photosynthesis to increase in water content was as expected for mosses although B. subrotundifolium showed a large depression (60%) at the highest hydrations. Net photosynthesis of both B. subrotundifolium and B. pseudotriquetrum showed a large response to increase in CO2 concentration and this rose with increase in temperature; saturation was not reached for B. pseudotriquetrum at 20°C. There was a high level of variability for species at the same sites in different years and between different locations. This was substantial enough to make prediction of the effects of climate change very difficult at the moment.

Effect of Leaf Position, Expansion and Age on Photosynthesis, Transpiration and Water Use Efficiency of Cotton

1980 ◽  
Vol 7 (1) ◽  
pp. 89 ◽  
Author(s):  
GA Constable ◽  
HM Rawson
Keyword(s):  
Water Use Efficiency ◽  
Water Use ◽  
Dark Respiration ◽  
Vapour Pressure Deficit ◽  
Initial Slope ◽  
Photon Flux ◽  
Morphological Development ◽  
Leaf Position ◽  
Leaf Unfolding ◽  
Use Efficiency

Net photosynthesis, dark respiration and the response to photon flux density were measured on cotton leaves grown in a glasshouse. Leaves at four positions on the plant were examined from their unfolding until 70 days later. Photosynthesis and transpiration per unit of leaf area were unaffected by leaf position and, in all leaves, peak photosynthesis of about 110 ng CO2 cm-2 s-1 was attained 13-15 days after leaf unfolding, when the leaf was 75-90% of maximum area. Photosynthesis was maintained at this rate for only 12 days before declining linearly to values 20% of the maximum when leaves were 70 days old. Transpiration followed a similar pattern reaching a maximum of about 13 �g H2O cm-2 s-1 at 2 kPa vapour pressure deficit (VPD) at 13 days. Stomatal and internal conductances changed in parallel as leaves aged, with the consequence that internal CO2 concentration and water use efficiency remainedessentially constant at 220�ll-1 and 16.8 ng CO2 (�g H2O kPa VPD-1)-1 respectively. Youngest and oldest leaves saturated at lowest light levels (400-800 pE m-2 s-1) while 16-18- day-old leaves had light saturation at 1100 �E m-2 s-1. The initial slope of the light response curves increased as leaves expanded up to 10 days age then remained constant at 0.25 ng CO2 cm-2 (pE m-2)-1. Dark respiration reached a maximum of 1.5 ng CO2 mg-1 s-1 5 days after leaf unfolding, when leaf dry weight was increasing most rapidly. The relationship between the consistent pattern of gas exchange with age and the pattern of morphological development is discussed, along with internal factors associated with age-dependent photosynthesis.

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