scholarly journals Genetic Variations in Chlorophyll Fluorescence, Photosynthesis, and Carbon Partitioning into Sorbitol, Sucrose, and Starch in Apple Leaves

HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 886D-886
Author(s):  
Zhongchun Wang ◽  
Bruno Quebedeaux

Chlorophyll fluorescence measurements are providing insights into Photosystem II (PSII) quantum efficiency and hence are able to provide a good estimation of carbon assimilation under field conditions. A F2 generation of sibcross seedlings from a cross of `Goldspur' × `Redspur' were selected to identify genetic variations and the relationships among fluorescence parameters, carbon assimilation, and carbon partitioning in apple leaves. Mature leaves from extension shoots were analyzed for chlorophyll fluorescence with a CF-1000 chlorophyll fluorescence measurement system, photosynthetic rate with a LI-6200 portable photosynthesis system, and carbohydrates with a Shimadzu HPLC. Significant variations in leaf chlorophyll fluorescence parameters and photosynthetic rates were found. The ratio of Fv: Fm, an estimation of photochemical efficiency of PSII, decreased from ≈0.90 in June to ≈0.75 in September while the photosynthetic rates decreased from ≈8.5 in June to ≈4.5 μmol·m–2·s–l in September. The relationships between fluorescence parameters, photosynthesis, and carbohydrate partitioning were analyzed and the ratio of sorbitol to sucrose in relation to the efficiency of PSII and NADPH production will be discussed.

2018 ◽  
Vol 8 (2) ◽  
pp. 218-229 ◽  
Author(s):  
Yeray Folgar Cameán ◽  
Miloš Barták

In this study, we evaluated the effects of low and sub-zero temperature on the fast chlorophyll fluorescence transient (OJIP) and OJIP-derived parameters in 4 different mosses: Sphagnum girgensohnii, Polytrichum formosum, Hylocomium splendens and Pleurozium schreberi. The low temperature stress was applied on the mosses for 90 min. at 3 different temperatures (5°C, -1°C and -10°C). To investigate the effects of this stress on the functioning of photosystem II (PS II), the chlorophyll fluorescence measurements were taken at control temperature (22°C) and, after a 90 min. acclimation period, at each experimental temperature. The shape of OJIP curves and chlorophyll fluorescence parameters were found temperature-dependent in all the species. The mosses differed in their sensitivity to the stress but general trends in response to low temperature were similar. The results support the idea that S. girgensohnii is less resistant to low temperature stress than the other species. We were also interested in the K and L steps in OJIPs, representing different disorders caused by low temperature. The K-step was seen in P. formosum and P. schreberi and the L-step in H. splendens and S. girgensohnii.


2018 ◽  
Vol 8 (2) ◽  
pp. 198-207
Author(s):  
Marta Campos Alonso

Hassallia antarctica is a terrestrial cyanobacterium colonizing various habitats in Antarctica such as soil surface, microbiological mats and seepages. H. antarctica represents one of the cyanobacterial species forming biodiversity of terrestrial autotrophs of James Ross Island, Antarctica. It is a filamentous cyanobacterium composing blackish fasciculated clusters thanks to false branching. In our study, sensitivity of the species to dehydration and salt stress was studied. We used H. antarctica culture (CCALA 956) grown on Z liquid medium. Clusters of H. antarctica were placed on wet filter paper and dried naturally at 5°C. During gradual dehydration, relative water content (RWC) was evaluated gravimetrically simultaneously with chlorophyll fluorescence measurements. Slow Kautsky kinetics and the chlorophyll fluorescence parameters (FV/FM, ФPSII) were used to assess dehydration-related decrease in primary photosynthetic processes. It was found that H. antarctica, contrastingly to other terrestrial cyanobacteria from polar habitats, was not able to maintain photosynthetic processes at RWCs as low as 20%. Even during initial phase of dehydration (RWC of 95%) rapid decline in FV/FM occured. Resistance of H. antarctica to osmotic stress was studied by time courses of the chlorophyll fluorescence parameter in response to 3.0, 0.3, and 0.03 M NaCl solution. Both shape of slow Kautsky kinetics and numeric values of chlorophyll fluorescence parameters were affected by osmotic stress. While full inhibitory effect was apparent in 3.0 M NaCl treatment immediately, the salt stress-induced decline in chlorophyll fluorescence parameters was observed at 0.03 M NaCl even after 8 hours of exposition. It was, therefore, concluded that H. antarctica exhibited high resistance to osmotic stress which may help the species to cope with repetitive dehydration events that happen in the field during austral summer season in Antarctica, James Ross Island in particular.


2019 ◽  
Vol 11 (16) ◽  
pp. 1885 ◽  
Author(s):  
Marlena Kycko ◽  
Elżbieta Romanowska ◽  
Bogdan Zagajewski

Chlorophyll fluorescence parameters can provide useful indications of photosynthetic performance in vivo. Coupling appropriate fluorescence measurements with other noninvasive techniques, such as absorption spectroscopy or gas exchange, can provide insights into the limitations to photosynthesis under given conditions. Chlorophyll content is one of the dominant factors influencing the conditions of a vegetation growing season, and can be tested using both fluorescence and remote sensing methods. Hyperspectral remote sensing and recording the narrow range of the spectrum can be used to accurately analyze the parameters and properties of plants. The aim of this study was to analyze the influence of lead ions (Pb, 5 mM Pb(NO3)2) on the growth of pea plants using spectral properties. Hyperspectral remote sensing and chlorophyll fluorescence measurements were used to assess the physiological state of plants seedlings treated by lead ions during the experiment. The plants were growing in hydroponic cultures supplemented with Pb ions under various conditions (control, complete Knop + phosphorus (+P); complete Knop + phosphorus (+P) + Pb; Knop (-P) + Pb, distilled water + Pb) affecting lead uptake via the root system. Spectrometric measurements allowed us to calculate the remote sensing indices of vegetation, which were compared with chlorophyll and carotenoids content and fluorescence parameters. The lead contents in the leaves, roots, and stems were also analyzed. Spectral characteristics and vegetation properties were analyzed using statistical tests. We conclude that: (1) pea seedlings grown in complete Knop (with P) and in the presence of Pb ions were spectrally similar to the control plants because lead was not transported to the shoots of plants; (2) lead most influenced plants that were grown in water, according to the highest lead content in the leaves; and (3) the effects of lead on plant growth were confirmed by remote sensing indices, whereas fluorescence parameters identified physiological changes induced by Pb ions in the plants.


2011 ◽  
Vol 356-360 ◽  
pp. 2785-2790 ◽  
Author(s):  
Liu Qing Yang ◽  
Fei Yong Liao ◽  
Kun Zhao

Solidago canadensis L. was treated with metsulfuron-methyl, fluroxypyr and iso-propyl glyphosate. The photosynthetic rate and chlorophyll fluorescence parameters were measured. The results showed that after treated 13 days later, the intrinsic conversion efficiency of light energy decreased, treatment A1B3 had the largest decline, which was 81.6 % of the control, the changes of treatments treated with iso-propyl glyphosate were not obvious; the photochemical quenching parameter of all treatments decreased, treatment A2B2 had the largest decline, which was 42.6 % of control; the photosynthetic electron transport rate decreased obviously, treatment A1B2,A1B3 and A2B2 had the largest decline, which was 20.0 % of control; the net photosynthetic rate decreased greatly, treatment A2B2 and A2B3 drooped more than others, which were 11.3% and 17.8% of control respectively. After treated 50 days later, the plants treated with metsulfuron-methyl and fluroxypyr were dead, whose net photosynthetic rates were zero. The net photosynthetic rates of the plants treated with iso-propyl glyphosate decreased to varying degrees, but plants were alive. Result shows that metsulfuron-methyl and fluroxypyr could be used to kill the Solidago canadensis L., the plants would be dead after treated 50 days later.


Weed Science ◽  
2008 ◽  
Vol 56 (4) ◽  
pp. 574-581 ◽  
Author(s):  
Giovanni Mauromicale ◽  
Antonino Lo Monaco ◽  
Angela M. G. Longo

The influence of the holoparasite branched broomrape on the vegetative growth, leaf chlorophyll content, photosynthetic rate, and chlorophyll fluorescence of tomato was studied over two growing seasons on plants grown in a commercial greenhouse. The presence of the parasite strongly reduced the aerial biomass by acting as a competing sink for assimilate, but more importantly, by compromising the efficiency of carbon assimilation via a reduction in leaf chlorophyll content and photosynthetic rate. The chlorophyll fluorescence parameters F0, Fm, Fv, and Fv/Fm were all altered in parasitized plants, indicating that branched broomrape–infected plants are more susceptible to photoinhibition. The degree of damage to the host was not dependent on either the number or the biomass of parasitic plants per host plant. We suggest that the ability to maintain a high photosynthetic rate, leaf chlorophyll content, or both and the ability to minimize photoinhibition can be developed as indirect assays for improved tolerance to branched broomrape.


2006 ◽  
Vol 39 (1) ◽  
pp. 91-100 ◽  
Author(s):  
Marie KUMMEROVÁ ◽  
štěpán ZEZULKA ◽  
Jana KRULOVÁ ◽  
Jan TŘÍSKA

The effect of increasing concentrations (0·01, 0·1, 1 and 5 mg l−1) of intact (FLT) and photo-modified (phFLT) fluoranthene and the duration of exposure (1, 2, 3, 5 and 7 days) on the chlorophyll fluorescence parameters (F0, FV/FM, and ΦII) of symbiotic algae in the thalli of two foliose lichens Lasallia pustulata and Umbilicaria hirsuta was investigated. In addition the FLT concentration in thalli of both lichen species was determined and a bioconcentration factor (BCF) was calculated. The results obtained demonstrated that the concentrations of FLT and especially phFLT (1 and 5 mg l−1) applied affected primary photochemical processes of photosynthesis in the algae of both lichen species. The F0 value increased and the FV/FM and ΦII values decreased. The fluoranthene content in the thallus of both lichen species increased with increasing FLT concentration in the environment.


Author(s):  
Guotao Peng ◽  
Zhengqiu Fan ◽  
Xiangrong Wang ◽  
Chen Chen

<p>The frequent outbreak of cyanobacterial blooms has become a worldwide phenomenon in freshwater ecosystems. Studies have elucidated the close relationship between harmful algal blooms and nutrient contents, including the loading of nitrogen and the ratios of nitrogen (N) and phosphorus (P). In this study, the effect of inorganic (nitrate and ammonium) and organic (urea) nitrogen at varied N/P ratios on the <em>Microcystis</em> <em>aeruginosa</em> FACHB-905 accumulation and photosynthesis was investigated.  The optimal NO<sub>3</sub>/P in this study were 30~50 indicated by the cell abundance (4.1×10<sup>6</sup>/mL), pigment concentration (chlorophyll a 3.1 mg/L,  phycocyanin 8.3mg/L), and chlorophyll fluorescence parameters (<em>rETR</em>, <em>E<sub>k</sub>, α, φPSII</em> and <em>F<sub>v</sub>/F<sub>m</sub> </em>values), while too high NO<sub>3</sub>-N (N/P=100:1) would cause an intracellular nitrate inhibition, leading to a decrease of photosynthetic activity. In addition, low concentration of NH<sub>4</sub>-N (N/P=4:1) would favor the <em>M. aeruginosa </em>growth and photosynthesis, and high NH<sub>4</sub>/P ratio (&gt;16) would rise the ammonium toxicity of algal cells and affect the N assimilation. In urea treatments, <em>M. aeruginosa </em>responded similarly to the NH<sub>4</sub>-N treatments both in growth curves and pigment contents, and the favorable N/P ratio was between 16~30, suggested by the chlorophyll fluorescence parameters. The results demonstrated that the various chemical forms of N and N/P ratios have a significant impact on <em>Microcystis</em> abundance and photosynthesis. More work is needed to figure out the mechanism of nitrogen utilization by <em>Microcystis</em> and  the photosynthetic response to nutrient stress at the molecular level.</p>


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