Effect of irradiance on growth and photosynthesis of Populus × euramericana clones

1978 ◽  
Vol 8 (1) ◽  
pp. 94-99 ◽  
Author(s):  
F. E. Fasehun
Keyword(s):  
Growth Rate ◽  
Laboratory Experiments ◽  
Dark Respiration ◽  
High Irradiance ◽  
Dark Respiration Rate ◽  
Photosynthetic Rates ◽  
Populus Euramericana ◽  
Unit Leaf ◽  
Whole Plant ◽  
Plant Photosynthesis

Greenhouse and laboratory experiments were conducted to determine the effect of irradiance level on growth and photosynthesis of three Populus × euramericana clones selected to exhibit differences in growth rate when grown under full sunlight. Individual plants were started from apical cuttings and grown in the greenhouse for 13 weeks under three levels of shading (37%, 75%, and 100% full light). Rates of leaf and whole plant photosynthesis and dark respiration were measured with an infrared gas analyzer.Clone 5323 grew relatively well under all irradiance levels, and the older leaves of this clone had the highest photosynthetic rates per unit leaf area under the higher growth irradiances. Clone 5326, which had the least growth, also had the lowest per-plant photosynthesis rate under all irradiance levels. Clone 5321 had per-plant photosynthetic rates comparable with those of clone 5323 but a higher dark respiration rate when grown at the high irradiance levels.

Responses of the apple plant to CO2 enrichment: changes in photosynthesis, sorbitol, other soluble sugars, and starch

1998 ◽  
Vol 25 (3) ◽  
pp. 293 ◽  
Author(s):  
Q. Pan ◽  
Z. Wang ◽  
B. Quebedeaux
Keyword(s):  
Elevated Co2 ◽  
Soluble Sugars ◽  
Co2 Enrichment ◽  
Carbohydrate Accumulation ◽  
Photosynthetic Rates ◽  
Mature Leaves ◽  
Whole Plant ◽  
Plant Photosynthesis ◽  
Apple Plant ◽  
Ambient Co2

There is no information on the effects of elevated [CO2] on whole-plant photosynthesis and carbohydrate metabolism in apple (Malus domestica Borkh.) and other sorbitol-translocating plants. Experiments were conducted in controlled growth chambers to evaluate how increases in [CO2] affect plant photosynthesis and carbon partitioning into soluble sugars and starch in apple leaves. Apple plants (cv. Gala), 1-year-old, were exposed to [CO2] of 200, 360, 700, 1000, and 1600 µL L-1 up to 8 d. Whole-plant net photosynthetic rates were analysed daily after [CO2] treatments. Newly expanded mature leaves were sampled at 1, 2, 4, and 8 d after [CO2] treatments for sorbitol, sucrose, glucose, fructose, and starch analysis. Midday whole-plant net photosynthetic rates increased linearly with increasing [CO2], but the differences in whole-plant photosynthesis between CO2-enrichment and ambient [CO2] treatments were less significant as apple plants acclimated to high atmospheric [CO2] for 8 d. Increases in [CO2] significantly increased sorbitol and starch, but did not affect sucrose concentrations. As a result, the ratios of starch to sorbitol and starch to sucrose at 8 d after [CO2] treatments were increased from 0.05 and 0.06 to 0.8 and 1.6 as [CO2] increased from ambient [CO2] (360 µL L-1) to 1000 µL L-1 [CO2], respectively. The sorbitol to sucrose ratio also increased from 1.3 to 2.2 as [CO2] increased from 360 to 1000 µL L-1. Elevated [CO2] enhanced the photosynthesis of apple plants and altered carbohydrate accumulation in mature leaves in favour of starch and sorbitol over sucrose.

scholarly journals Postproduction Leaching Affects the Growing Medium and Respiration of Subirrigated Poinsettias

HortScience ◽  
2000 ◽  
Vol 35 (2) ◽  
pp. 250-253 ◽  
Author(s):  
Marc van Iersel
Keyword(s):  
Dark Respiration ◽  
Plant Stress ◽  
Middle Layer ◽  
Bottom Layer ◽  
Euphorbia Pulcherrima ◽  
Whole Plant ◽  
Growing Medium ◽  
Plant Photosynthesis ◽  
Saturated Medium ◽  
Fertilizer Solution

Poinsettias (Euphorbia pulcherrima Willd. ex Klotzsch) were grown in pots filled with 1.5 L of soilless growing medium and subirrigated daily with a fertilizer solution containing N at 210 mg·L-1 [electrical conductivity (EC) = 1.5 dS·m-1] for 128 days. After production, plants were placed in a whole-plant photosynthesis system and the effects of applying different volumes of water (0, 0.75, 1.5, and 3 L) to the top of the pots were quantified. Leaching with 0.75, 1.5, or 3 L of water reduced the EC in the top and middle layers of the growing medium. Applications of 0.75 or 1.5 L of water significantly increased the EC in the bottom third of the pots, where most of the root growth occurred. However, even in these treatments the EC in the bottom layer was only 2.6 dS·m-1 (saturated medium extraction method), which is well within the recommended range. The 0.75- and 1.5-L treatments also reduced the respiration rate of the plants by 20%, but none of the treatments had a significant effect on the photosynthesis of the plants. Regression analysis indicated a negative correlation between the EC of the bottom layer of the growing medium and dark respiration, while the EC of the top and middle layer had no significant effect on respiration. Although top watering can increase the EC in the bottom layer of the growing medium, this effect is unlikely to be large enough to cause significant plant stress and damage.

Correlation Between the Rates of Foliar Dark Respiration and Net Photosynthesis in Some Tropical Dicot Weeds

Weed Science ◽  
1987 ◽  
Vol 35 (2) ◽  
pp. 141-144 ◽  
Author(s):  
G. Rajendrudu ◽  
J. S. Rama Prasad ◽  
V. S. Rama Das
Keyword(s):  
Respiration Rate ◽  
Dark Respiration ◽  
Leaf Age ◽  
Net Photosynthesis ◽  
Dark Respiration Rate ◽  
Weed Species ◽  
Unit Leaf ◽  
Positive Linear Correlation ◽  
Carbohydrate Levels ◽  
Photosynthetic Type

The rates of foliar dark respiration and net photosynthesis in attached leaves of 25 C3, C4, and C3-C4 intermediate dicotyledonous weed species were determined using the infrared gas analyzer. The ratio of dark respiration to photosynthesis per unit leaf area in attached leaves of each species was inversely proportional to leaf age. Highly significant, positive linear correlation was observed between the rates of foliar dark respiration and net photosynthetic CO2 uptake in dicot weeds irrespective of the photosynthetic type. The higher foliar dark respiration rate found in some of the weed species can be attributed in part to the higher carbohydrate levels as generated by a rapid photosynthetic CO2 assimilation. The significance of higher dark respiration rate in relation to carbon and energy economy of weeds is discussed.

Effect of Nitrogen Content on the Photosynthetic Characteristics of Sunflower Leaves

1993 ◽  
Vol 20 (3) ◽  
pp. 251 ◽  
Author(s):  
DJ Connor ◽  
AJ Hall ◽  
VO Sadras
Keyword(s):  
Nitrogen Content ◽  
Dark Respiration ◽  
Net Photosynthesis ◽  
Leaf Nitrogen ◽  
Mean Value ◽  
Life Cycles ◽  
High Irradiance ◽  
Response Curves ◽  
Unit Leaf ◽  
Wide Range

Photosynthesis-irradiance response curves and leaf nitrogen contents were measured weekly by destructive sampling over the life cycles of leaves 10, 15, 20 and 25 of sunflower plants (cv. Prosol 35) grown in large pots in the open under optimum conditions of temperature and high irradiance. Individual leaf responses were adequately described by a hyperbola of three parameters, viz. Pmax, the rate of photosynthesis in saturating irradiance; R, the rate of dark respiration adjusted for temperature (30�C); and ε, the apparent quantum efficiency of photosynthesis at low irradiance. Pmax (range 0-40 μmol CO2 m-2 s-1) and R (0-4 μmol CO2 m-2 s-1) were non-linearly related to nitrogen content per unit leaf area (NL) (range 0.3-2.9 g N m-2) across all leaf positions and for all leaf ages. ε (mean value 0.050 mol mol-1, s.e. 0.001) was independent of NL. The equations for net photosynthesis derived from pot studies were shown to explain (r2 =0.80) leaf photosynthesis in a crop of the same cultivar over a wide range of NL and irradiance.

scholarly journals Whole-plant Photosynthesis of Containerized Hydrangeas and Abelias as Affected by Substrate Moisture Content

HortScience ◽  
2005 ◽  
Vol 40 (4) ◽  
pp. 1111D-1111 ◽  
Author(s):  
Marc W. van Iersel ◽  
Sue Dove
Keyword(s):  
Growth Rate ◽  
Drought Stress ◽  
Moisture Content ◽  
Water Potential ◽  
Photosynthetic Rate ◽  
Severe Drought ◽  
Whole Plant ◽  
Growing Medium ◽  
Plant Photosynthesis ◽  
Substrate Moisture

Efficient water use in nurseries is increasingly important. In recent years, new soil moisture sensors (ECH2O probes) have become available, making it possible to monitor the moisture content of the growing medium in containers. One piece of information that is lacking for fully-automated irrigation systems is how much water actually needs to be present in the growing medium to prevent detrimental effects of drought on plants. We determined the effect of substrate moisture on photosynthesis and plant water relations of hydrangea and abelia. Growth rates of these species were measured during two subsequent drying cycles to determine how drought affects the growth rate of these species. Whole-plant photosynthesis, an indicator of growth rate, of both species remained stable as the volumetric moisture content of the substrate dropped from 25% to 15%, with pronounced decreases in photosynthesis at lower substrate moisture levels. Abelias and hydrangeas wilted when the substrate moisture level dropped to 6.3% and 8.3%, respectively. At wilting, abelias had lower leaf water potential (–3.7 MPa) than hydrangeas (–1.8 MPa). After the plants were watered at the end of the first drying cycle, the photosynthesis of the plants did not recover to pre-stress rates, indicating that the drought stress caused a long-term reduction in photosynthesis. Despite the more severe drought stress in the abelias (both a lower substrate water content and lower water potential at wilting), abelias recovered better from drought than hydrangeas. After the plants were watered at the end of the first drying cycle, the photosynthetic rate of abelias recovered to ≈70%, while the photosynthetic rate of the hydrangeas recovered to only 62% of the pre-stress rate.

scholarly journals Comparative response to nitrogen deficiency of a tropical and temperate grass in the interrelation between photosynthesis, growth, and the accumulation of non-structural carbohydrate.

1975 ◽  
Vol 23 (2) ◽  
pp. 104-112
Author(s):  
J.R. Wilson
Keyword(s):  
Growth Rate ◽  
Leaf Area ◽  
Nutrient Solution ◽  
Dark Respiration ◽  
Initial Period ◽  
Nitrogen Deficiency ◽  
Treated Group ◽  
Panicum Maximum ◽  
Unit Leaf ◽  
Structural Carbohydrate

A tropical grass, Panicum maximum var. trichoglume and a temperate grass, Lolium perenne, were grown in controlled environment rooms at near optimum temperatures of 25 and 18 deg C, respectively. After an initial period of growth on full nitrogen nutrient solution, a proportion of the plants of both species were transferred to 'nil' N nutrient solution. A sequence of destructive harvests was taken as the plants became increasingly N deficient, and calculations were made of relative growth rate (RW), relative leaf area growth rate (RA) and net assimilation rate per unit leaf area (EA). On a similarly treated group of plants, net photosynthetic rate (PN) and dark respiration rate of attached leaves were measured.Organic and nitrate N were estimated on the photosynthesis-tested leaves, and on comparable leaves from the growth analysis plants at each harvest. Percentage total non-structural carbohydrate (%TNC) was estimated for P. maximum only.P. maximum maintained a higher RW and PN than L. perenne at comparable percent leaf N. With increasing N stress, EA of both species declined to a similar relative extent, but RA of P. maximum decreased much less than that of L. perenne. This difference in response to N between the species in the balance of assimilate input and consumption in new growth may in part explain why, under N deficiency, published studies indicate that % TNC reach higher levels in L. perenne and other temperate grasses than in tropical grasses such as P. maximum. (Abstract retrieved from CAB Abstracts by CABI’s permission)

scholarly journals A COMPARISON OF LEAF AND WHOLE PLANT NET PHOTOSYNTHESIS IN ALSTROEMERIA

HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 576c-576
Author(s):  
E.D. Leonardos ◽  
M.J. Tsujita ◽  
B. Grodzinski ◽  
T.J. Blom
Keyword(s):  
Dark Respiration ◽  
Net Photosynthesis ◽  
Stomatal Resistance ◽  
Gas Analysis ◽  
Whole Plant ◽  
Plant Photosynthesis ◽  
Mutual Shading ◽  
Photosynthetic Responses ◽  
Analysis System ◽  
Two Stages

Gas exchange (net photosynthesis Pn, dark respiration, transpiration, and stomatal resistance) of `Jaqueline' Alstroemeria, grown in pots in a greenhouse, were measured. Measurements were made under laboratory conditions using an open-flow infrared gas analysis system for leaf studies, and a semi-closed computer controlled whole plant photosynthesis system for whole plant studies. Apical fully expanded leaves on non-flowering and flowering (at two stages) shoots had similar photosynthetic responses in respect to photosynthetically active radiation (PAR) and to CO2 concentration. Light saturation occurred at 600 umol/m2/s PAR with maximum leaf Pn rates ranging from 9 to 11 umol CO2/m2/s. CO2 saturation was estimated at approximately 1100 to 1200 ppm with maximum leaf Pn rates from 17 to 22 umol CO2/m2/s. Whole plant Pn rates increased with increased PAR. Maximum rates 4 to 5 umol CO2/m2/s (half that of individual leaves) occurred at approximately 1000 to 1100 umol/m2/s PAR. CO2 saturation was estimated at 1100 to 1200 ppm, with maximum whole plant Pn rates ranging from 7 to 8 umol CO2/m2/s. These data will be discussed in relation to respiration and mutual shading at the leaf canopy.

scholarly journals 155 Fertilizer Concentration Affects Whole Plant CO2 Exchange and Growth of Subirrigated Pansies

HortScience ◽  
2000 ◽  
Vol 35 (3) ◽  
pp. 416D-416
Author(s):  
Marc van Iersel ◽  
Jong-Goo Kang
Keyword(s):  
Root System ◽  
Dark Respiration ◽  
Net Photosynthesis ◽  
Co2 Exchange ◽  
Bedding Plants ◽  
Whole Plant ◽  
Growing Medium ◽  
Wide Range ◽  
K Deficiency ◽  
Plant Photosynthesis

Subirrigation is an economically attractive irrigation method for producing bedding plants. Because excess fertilizer salts are not leached from the growing medium, salts can accumulate in the growing medium. Fertilizer guidelines developed for overhead irrigation may not be appropriate for subirrigation systems. Our objective was to quantify the effect of the fertilizer concentration (N at 0, 135, 285, and 440 mg·L–1) on whole-plant CO2 exchange and growth of subirrigated pansies. Whole plant CO2 exchange rate (net photosynthesis and dark respiration) was measured once every 10 min for 31 days. Whole-plant photosynthesis, dark respiration, and carbon use efficiency increased during the experiment. Fertilizer concentration started to affect the growth rate of the plants after approximately 7 days. Maximum photosynthesis and growth were achieved with N at about 280 mg·L–1 in the fertilizer solution [electrical conductivity = 2 dS·m–1]. Growth was reduced by ≈10% when the plants were fertilized with N at 135 and 440 mg·L–1 compared to 280 mg·L–1. Growth of plants watered without any fertilizer was greatly reduced, and plants showed symptoms of N and K deficiency. The size of the root system decreased and the shoot: root ratio increased with increasing fertilizer concentration, but the size of the root system was adequate in all treatments. These results indicate that subirrigated pansies can tolerate a wide range of fertilizer concentrations with relatively little effect on plant growth.

scholarly journals Photosynthetic characteristics of a tropical population of Nitella cernua (Characeae, Chlorophyta)

2006 ◽  
Vol 18 (3) ◽  
pp. 379-388 ◽  
Author(s):  
Jair Vieira Jr. ◽  
Orlando Necchi Jr.
Keyword(s):  
Dark Respiration ◽  
Net Photosynthesis ◽  
Wide Distribution ◽  
Photosynthetic Performance ◽  
High Irradiance ◽  
Photosynthetic Characteristics ◽  
Southeastern Brazil ◽  
Photochemical Quenching ◽  
O2 Evolution ◽  
Photosynthetic Rates

Photosynthetic characteristics (assessed by chlorophyll fluorescence and O2 evolution) were analysed monthly during one year in a tropical population of Nitella cernua from southeastern Brazil (20º50'32" S, 49º26'15" W). Parameters derived from photosynthesis-irradiance (PI) curves by fluorescence (high values of the photosynthetic parameter, Ik, and lack or low values of photoinhibition, beta) suggested adaptation to high irradiance, whereas those by O2 evolution showed a different pattern (low values of Ik and compensation irradiance, Ic, high values of photosynthetic efficiency, alpha, and photoinhibition). Parameters from PI curves by O2 evolution suggested light acclimation: Ik and maximum photosynthetic rate, Pmax (as rETR, relative electron transfer rate) increased, whereas a became significantly lower under higher irradiance (winter). This pattern is an adjustment of both number and size of photosynthetic units. Photosynthetic performance assessed by fluorescence revealed two seasonal periods: higher values of Pmax (rETR), Ik and non-photochemical quenching from October to March (rainy season), and lower values from April to October (dry season). Temperature responses were observed only in summer, but temperature optima were different between methods: peaks of net photosynthesis occurred at 20ºC, whereas rETR increased towards higher temperatures (up to 30ºC). Dark respiration increased with higher temperatures. Current velocity had a stimulatory effect on photosynthetic rates, as suggested by positive correlations with Pmax (rETR) and alpha. pH experiments revealed highest net photosynthetic rates under pH 4.0, suggesting higher affinity for CO2 than HCO3-. This broad range of responses of photosynthetic characteristics of this N. cernua population to irradiance, temperature, and pH/inorganic carbon reflects a wide tolerance to variations in these environmental variables, which probably contribute to the wide distribution of this species.

scholarly journals Responses of Angelica acutiloba Kitagawa Transplants to Elevated Ambient CO2 Concentration

HortScience ◽  
2019 ◽  
Vol 54 (5) ◽  
pp. 851-855
Author(s):  
Ming Li ◽  
Wei-tang Song
Keyword(s):  
Dark Respiration ◽  
Growth Management ◽  
Dry Weight ◽  
Co2 Concentration ◽  
Relative Growth ◽  
Whole Plant ◽  
Plant Photosynthesis ◽  
Angelica Acutiloba ◽  
Ambient Co2

Long-term exposure to an elevated ambient carbon dioxide (eCO2) concentration could weaken or diminish the enhancement of plant photosynthesis and growth. To monitor this response and offer references for growth management, the whole-plant photosynthetic rate (Pn,w) and dark respiration rate (Rd,w) of Angelica acutiloba Kitagawa transplants were monitored with a growth chamber. The results showed that eCO2 increased both the Pn,w and Rd,w by (79 ± 42) % and (126 ± 51) %. The dry weight of transplants under eCO2 was 33.6% greater than that under aCO2. However, the photosynthetic acclimation to eCO2 occurred. The increase in the Pn,w was maintained until the end of the experiment due to increased leaf area. Moreover, the increase in plant dry weight mainly occurred in the first 15 days of treatment. Furthermore, the dry weight estimated based on the Pn,w and Rd,w agreed well with the measured dry weight. The relative growth rate (RGR) calculated with the estimated dry weight demonstrated the response of transplant growth to eCO2. These results indicated that the proposed method can be used to monitor the response of plant growth to eCO2.

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