scholarly journals PHOTOSYNTHESIS, RESPIRATION, AND CARBON COST OF DEVELOPING RABBITEYE BLUEBERRY FRUIT

HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1165g-1166
Author(s):  
Keith Birkhold ◽  
Rebecca Darnell ◽  
Karen Koch
Keyword(s):  
Weight Gain ◽  
Fruit Development ◽  
Dark Respiration ◽  
Net Photosynthesis ◽  
Dry Weight ◽  
Total Carbon ◽  
Vaccinium Ashei ◽  
Gross Photosynthesis ◽  
Carbon Cost ◽  
Fruit Photosynthesis

Carbon exchange and content of blueberry (Vaccinium ashei) fruit were measured from anthesis through fruit ripening in order to determine the amount of imported carbon required for fruit development. Net photosynthesis occurred in blueberry fruit from petal fall through color break. During this time, gross photosynthesis of fruit decreased from 30.1 μmol CO2·g fw-1·hr-1 to 4.8 μmol CO2·g fw-1·hr-1, and dark respiration decreased from 14.3 μmol CO2·g fw-1·hr-1 to 4.6 μmol CO2·g fw-1·hr-1. After color break, the photosynthetic rate fell to zero, and the respiration rate increased to 8.0 μmol CO2·g fw-1·hr-1, before decreasing. Preliminary data suggest that fruit photosynthesis contributes 11% of the total carbon required (dry weight gain + respiratory loss) during fruit development however, it supplies 50% of the total carbon required during the first 5 days after petal fall. This contribution of carbon from fruit photosynthesis may be critical in initial fruit development since the current season's vegetative growth is not yet providing carbohydrates.

scholarly journals PHOTOSYNTHESIS, RESPIRATION, AND CARBON COST OF DEVELOPING RABBITEYE BLUEBERRY FRUIT

HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1165G-1166
Author(s):  
Keith Birkhold ◽  
Rebecca Darnell ◽  
Karen Koch
Keyword(s):  
Weight Gain ◽  
Fruit Development ◽  
Dark Respiration ◽  
Net Photosynthesis ◽  
Dry Weight ◽  
Total Carbon ◽  
Vaccinium Ashei ◽  
Gross Photosynthesis ◽  
Carbon Cost ◽  
Fruit Photosynthesis

Carbon exchange and content of blueberry (Vaccinium ashei) fruit were measured from anthesis through fruit ripening in order to determine the amount of imported carbon required for fruit development. Net photosynthesis occurred in blueberry fruit from petal fall through color break. During this time, gross photosynthesis of fruit decreased from 30.1 μmol CO2·g fw-1·hr-1 to 4.8 μmol CO2·g fw-1·hr-1, and dark respiration decreased from 14.3 μmol CO2·g fw-1·hr-1 to 4.6 μmol CO2·g fw-1·hr-1. After color break, the photosynthetic rate fell to zero, and the respiration rate increased to 8.0 μmol CO2·g fw-1·hr-1, before decreasing. Preliminary data suggest that fruit photosynthesis contributes 11% of the total carbon required (dry weight gain + respiratory loss) during fruit development however, it supplies 50% of the total carbon required during the first 5 days after petal fall. This contribution of carbon from fruit photosynthesis may be critical in initial fruit development since the current season's vegetative growth is not yet providing carbohydrates.

scholarly journals Carbon and Nitrogen Economy of Developing Rabbiteye Blueberry Fruit

1992 ◽  
Vol 117 (1) ◽  
pp. 139-145 ◽  
Author(s):  
Keith T. Birkhold ◽  
Karen E. Koch ◽  
Rebecca L. Darnell
Keyword(s):  
Fruit Ripening ◽  
Fruit Development ◽  
Dark Respiration ◽  
Net Photosynthesis ◽  
Dry Weight ◽  
Carbon Dioxide Exchange ◽  
N Content ◽  
Vaccinium Ashei ◽  
Fruit Photosynthesis ◽  
C And N

Carbon dioxide exchange, dry weight, C, and N content of `Bonita' and `Climax' blueberry (Vaccinium ashei Reade) fruit were measured from anthesis through fruit ripening to quantify developmental changes in amounts of imported C and N required for fruit development. Net photosynthesis occurred in fruit of both rabbiteye cultivars from petal fall through color break. During this time, fruit net photosynthesis declined from 16 μmol CO2/g fresh weight (FW) per hour for `Bonita' and 22 μmol CO2/g FW per hour for `Climax' to 0.2 μmol CO2/g FW per hour for both. Dark respiration for both cultivars declined following petal fall from 16 μmol CO2/g FW per hour to 3 μmol CO2/g FW per hour before increasing at fruit ripening to 9 μmol CO2/g FW per hour. Fruit C content was constant at 0.43 mg C/mg dry weight (DW) throughout development, while N content declined from 0.05 mg N/mg DW at petal fall to 0.01 mg N/mg DW at ripeness. DW accumulation and respiration accounted for 63% and 37%, respectively, of the total C requirement for fruit development. Fruit photosynthesis was estimated to contribute 15% of the total C required for fruit development in both cultivars; however, fruit photosynthesis supplied 50% of the C required during the first 10 days after bloom and 85% during the 5 days after petal fall. This large, early contribution of C from fruit photosynthesis may aid in the establishment of fruit until the current season's vegetative growth can supplement plant carbohydrate reserves in providing C for fruit development.

Photosynthesis and Respiration of Developing Soybean Pods

1977 ◽  
Vol 4 (5) ◽  
pp. 713 ◽  
Author(s):  
EY Sambo ◽  
J Moorby ◽  
FL Milthorpe
Keyword(s):  
Dark Respiration ◽  
Photochemical Efficiency ◽  
Net Photosynthesis ◽  
Dry Weight ◽  
Daily Basis ◽  
Co2 Uptake ◽  
Response Curves ◽  
Total Import ◽  
Co2 Response ◽  
Gross Photosynthesis

Net CO2 uptake by soybean pods in the light was much less and output in darkness much greater than from equal areas of leaves. The net photosynthesis decreased, becoming negative, and dark respiration increased as seed filling progressed. The photochemical efficiency was the same but the diffusive resistance of pods was about twice and the internal resistance two to three times those of leaves. Fluxes into open deseeded pods were initially much greater than into intact pods but drying out of the tissue soon led to fluxes only about three times greater. From these measurements and light- and CO2-response curves of intact pods, estimates of gross photosynthesis, photorespiration and dark respiration of seeds and hulls were made. These indicated that seed reassimilated slightly more CO2 than they respired when young and about two-thirds thereof at a later stage. Hulls fixed about similar amounts but these were insufficient to prevent net effluxes from pods during the later stages of their development, even at irradiances of 190 W m-2. On a daily basis, direct uptake of CO2 made a negligible contribution to the total import of dry weight by the pod; nevertheless, photosynthesis in the seeds and hulls refixed some 50-70% of the CO2 respired by these tissues.

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.

Temperature Response of Whole-plant CO2 Exchange Rates of Magnolia (Magnolia grandiflora L.)

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 511d-511
Author(s):  
Marc W. van Iersel ◽  
Orville M. Lindstrom
Keyword(s):  
Dark Respiration ◽  
Temperature Response ◽  
Net Photosynthesis ◽  
Co2 Exchange ◽  
Limiting Factor ◽  
Response Curves ◽  
Gross Photosynthesis ◽  
Temperature Range ◽  
Whole Plant ◽  
Increasing Temperature

Photosynthesis and respiration temperature-response curves are useful in predicting the ability of plants to perform under different environmental conditions. Whole crop CO2 exchange of two groups of magnolia `Greenback' plants was measured over a 26 °C temperature range. Net photosynthesis (Pnet) increased from 2 to 17% C and decreased again at higher temperatures. The Q10 for Pnet decreased from ≈4 at 6 °C to 0.5 at 24 °C. The decrease in Pnet at temperatures over 17 °C was caused by a rapid increase in dark respiration (Rdark) with increasing temperature. The Q10 for Rdark was estimated by fitting an exponential curve to data, resulting in a temperature-independent Q10 of 2.8. Gross photosynthesis (Pgross), estimated as the sum of Rdark and Pnet, increased over the entire temperature range (up to 25 °C). The Q10 for Pgross decreased with increasing temperature, but remained higher than 1. The data suggest that high respiration rates may be the limiting factor for growth of magnolia exposed to high temperatures, since it may result in a net carbon loss from the plants. At temperatures below 5 °C, both Pnet and Rdark become low and the net CO2 exchange of the plants would be expected to be minimal.

Responses of the moss Tortula ruralis to desiccation treatments. I. Effects of minimum water content and rates of dehydration and rehydration

1981 ◽  
Vol 59 (12) ◽  
pp. 2698-2706 ◽  
Author(s):  
Mark W. Schonbeck ◽  
J. Derek Bewley
Keyword(s):  
Linear Growth ◽  
Dark Respiration ◽  
Natural Habitat ◽  
Dry Weight ◽  
Linear Growth Rate ◽  
Tissue Water ◽  
Visible Injury ◽  
Gross Photosynthesis ◽  
Tortula Ruralis ◽  
Water Contents

Samples of the moss Tortula ruralis were desiccated either rapidly or slowly to different tissue water contents to determine the limits of desiccation tolerance. Experimental samples were rehydrated rapidly by contact with wet filter paper, and gas exchange, chlorophyll content, electrolyte efflux, and linear growth rate were compared with those of control samples. Drying to 0.30–0.089 g H2O∙g dry weight−1 did not significantly affect the moss. Slow drying to 0.058–0.008 g H2O∙g dry weight−1 caused temporary increases in dark respiration and electrolyte leakage, and a slight inhibition of growth. Rapid drying of the same water contents caused visible injury, reduced total chlorophyll and the ratio of chlorophyll a:b, greatly enhanced electrolyte efflux, and severely inhibited gross photosynthesis and linear growth. The damaging effects of rapid drying could be eliminated either by partial desiccation for 1–3 h before rapid drying, or by placing the dry moss in a 100% relative humidity (RH) atmosphere for 1–5 h before rehydration.Tortula ruralis demonstrated greater drought tolerance than many other bryophytes, algae, seeds, and desert angiosperms, and is clearly capable of surviving any drought which might occur in its natural habitat.

Circadian rhythms of dark respiration, flowering, net photosynthesis, chlorophyll content, and dry weight changes in Chenopodium rubrum

1972 ◽  
Vol 50 (11) ◽  
pp. 2219-2226 ◽  
Author(s):  
Ah-Sing Chia-Looi ◽  
Bruce G. Gumming
Keyword(s):  
Circadian Rhythms ◽  
Chlorophyll Content ◽  
Dark Respiration ◽  
Net Photosynthesis ◽  
Dry Weight ◽  
Chenopodium Rubrum ◽  
Weight Changes ◽  
Physiological Processes ◽  
Dark Fixation ◽  
Relationship Of

There are circadian rhythmic changes in dark respiration, net photosynthesis, chlorophyll content, and dry weight in Chenopodium rubrum, ecotype 60°47′ N, 137°32′ W. The rhythm in dark respiration has a period of about 27 h and its phasing is quite closely correlated with the rhythm in flowering response, which has a period of about 30 h. A close similarity in the periodicity (21 h) and phasing of the rhythms in net photosynthesis and chlorophyll content suggests that the photosynthetic rhythm may be partly attributed to rhythmic changes in chlorophyll content. The rhythmic changes in dry weight, with a period of 18 h, could be due to a rhythm in dark fixation of carbon dioxide. The possible relationship of rhythmicity in these processes to other circadian rhythms that occur in C. rubrum is discussed. The concurrent existence of various rhythms in biochemical and physiological processes that differ in period and phase within a single ecotype of C. rubrum clearly reflects the possible involvement of metabolic activity in circadian rhythms.

Production, storage, and use of photosynthate during shoot elongation in balsam fir (Abies balsamea)

1973 ◽  
Vol 51 (6) ◽  
pp. 1161-1168 ◽  
Author(s):  
K. Loach ◽  
C. H. A. Little
Keyword(s):  
Dry Matter ◽  
Dark Respiration ◽  
Abies Balsamea ◽  
Net Photosynthesis ◽  
Dry Weight ◽  
Shoot Elongation ◽  
Extension Growth ◽  
Balsam Fir ◽  
Photosynthetic Production ◽  
Intermediate Time

Rates of net photosynthesis and dark respiration of 1-year-old and currently developing foliage were measured in the uppermost (i.e. 1-year-old) whorl of branches of 6-year-old balsam fir trees (Abies balsamea (L.) Mill.) during the period of extension growth of the current shoot. The rates were integrated to estimate net dry matter production by the two ages of foliage, and compared with dry matter requirements for growth of the new shoot (estimated from a regression equation of length over dry weight), and with cambial growth in the 1-year-old shoot (estimated from periodic harvests). The surplus of production over use in these two sinks was stored temporarily in the 1-year-old foliage or exported from the branch, the latter predominating. Two periods in which a large proportion of the photosynthetic production was exported (corresponding roughly to the months of May and July) were separated by a period when export was relatively low. At this intermediate time, current photosynthetic production was minimal and local growth demands were at their highest. Photosynthates stored in the 1-year-old foliage before budbreak supplemented current photosynthesis and permitted export to continue, except for a few days at the end of June. The contribution from stores in the old foliage, however, never exceeded one-third of current photosynthetic production. When extension growth terminated, a second transient storage peak occurred in the 1-year-old foliage for about 2 weeks. These observations explain the commonly observed reduction in root growth during current shoot extension, and corroborate results from studies made by other investigators using radioactive tracers.

scholarly journals Atmospheric CO2 availability induces varying responses in net photosynthesis, toxin production and N2 fixation rates in heterocystous filamentous Cyanobacteria (Nostoc and Nodularia)

2021 ◽  
Vol 83 (2) ◽  
Author(s):  
Nicola Wannicke ◽  
Achim Herrmann ◽  
Michelle M. Gehringer
Keyword(s):  
Nitrogen Availability ◽  
Dark Respiration ◽  
Net Photosynthesis ◽  
Dry Weight ◽  
Toxin Production ◽  
Oxygenic Photosynthesis ◽  
List Type ◽  
Filamentous Cyanobacteria ◽  
Biological Nitrogen ◽  
Stimulation Of

AbstractHeterocystous Cyanobacteria of the genus Nodularia form major blooms in brackish waters, while terrestrial Nostoc species occur worldwide, often associated in biological soil crusts. Both genera, by virtue of their ability to fix N2 and conduct oxygenic photosynthesis, contribute significantly to global primary productivity. Select Nostoc and Nodularia species produce the hepatotoxin nodularin and whether its production will change under climate change conditions needs to be assessed. In light of this, the effects of elevated atmospheric CO2 availability on growth, carbon and N2 fixation as well as nodularin production were investigated in toxin and non-toxin producing species of both genera. Results highlighted the following: Biomass and volume specific biological nitrogen fixation (BNF) rates were respectively almost six and 17 fold higher in the aquatic Nodularia species compared to the terrestrial Nostoc species tested, under elevated CO2 conditions. There was a direct correlation between elevated CO2 and decreased dry weight specific cellular nodularin content in a diazotrophically grown terrestrial Nostoc species, and the aquatic Nodularia species, regardless of nitrogen availability. Elevated atmospheric CO2 levels were correlated to a reduction in biomass specific BNF rates in non-toxic Nodularia species. Nodularin producers exhibited stronger stimulation of net photosynthesis rates (NP) and growth (more positive Cohen’s d) and less stimulation of dark respiration and BNF per volume compared to non-nodularin producers under elevated CO2 levels. This study is the first to provide information on NP and nodularin production under elevated atmospheric CO2 levels for Nodularia and Nostoc species under nitrogen replete and diazotrophic conditions.

scholarly journals Nutrient Solution Concentration Affects Whole-plant CO2 Exchange and Growth of Subirrigated Pansy

2002 ◽  
Vol 127 (3) ◽  
pp. 423-429 ◽  
Author(s):  
Marc W. van Iersel ◽  
Jong-Goo Kang
Keyword(s):  
Plant Growth ◽  
Exchange Rates ◽  
Leaf Area ◽  
Dark Respiration ◽  
Net Photosynthesis ◽  
Gross Photosynthesis ◽  
Whole Plant ◽  
Wide Range ◽  
Shoot To Root Ratio ◽  
Fertilizer Solution

To determine the effect of fertilizer concentration on plant growth and physiology, whole-plant C exchange rates of pansies (Viola ×wittrockiana Gams.) subirrigated with one of four fertilizer concentrations were measured over 30 days. Plants were watered with fertilizer solutions with an electrical conductivity (EC) of 0.15, 1.0, 2.0, or 3.0 dS·m-1 (N at 0, 135, 290, or 440 mg·L-1, respectively). Plants watered with a fertilizer solution with an EC of 2 dS·m-1 had the highest shoot dry weight (DW), shoot to root ratio, leaf area, leaf area ratio (LAR), and cumulative C gain at the end of the experiment compared to those watered with a solution with a higher or lower EC. Shoot tissue concentrations of N, P, K, S, Ca, Fe, Na, and Zn increased linearly with increasing fertilizer concentration. A close correlation between final DW of the plants and the measured cumulative C gain (CCG) (r2 = 0.98) indicated that the C exchange rates were good indicators of plant growth. There were quadratic relationships between fertilizer EC and gross photosynthesis, net photosynthesis, and dark respiration, starting at 13, 12, and 6 days after transplanting, respectively. Although plants fertilized with a fertilizer solution with an EC of 2 dS·m-1 had the highest C exchange rates, the final differences in shoot DW and CCG among ECs of 1.0, 2.0, and 3.0 dS·m-1 were small and it appears that pansies can be grown successfully with a wide range of fertilizer concentrations. Plants with a high LAR also had higher DW, suggesting that increased growth was caused largely by increased light interception. A detrimental effect of high fertilizer concentrations was that it resulted in a decrease in root DW and a large increase in shoot to root ratio.

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