scholarly journals Effect of Silicon on photosynthetic rate and the chlorophyll fluorescence parameters at hydroponically grown cucumber plants under salinity stress

2019 ◽  
Vol 20 (3) ◽  
pp. 953-960 ◽  
Author(s):  
Adelina Harizanova ◽  
Lyubka Koleva-Valkova
Keyword(s):  
Chlorophyll Fluorescence ◽  
Salinity Stress ◽  
Photosynthetic Rate ◽  
Chlorophyll Fluorescence Parameters ◽  
Fluorescence Parameters ◽  
Hydroponically Grown

Effect of Herbicides on the Photosynthetic Rate and Chlorophyll Fluorescence of Solidago canadensis L.

2011 ◽  
Vol 356-360 ◽  
pp. 2785-2790 ◽  
Author(s):  
Liu Qing Yang ◽  
Fei Yong Liao ◽  
Kun Zhao
Keyword(s):  
Chlorophyll Fluorescence ◽  
Photosynthetic Rate ◽  
Electron Transport Rate ◽  
Photosynthetic Electron Transport ◽  
Photochemical Quenching ◽  
Solidago Canadensis ◽  
Chlorophyll Fluorescence Parameters ◽  
Photosynthetic Rates ◽  
Fluorescence Parameters ◽  
Metsulfuron Methyl

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.

scholarly journals Chlorophyll fluorescence analysis in diverse rice varieties reveals the positive correlation between the seedlings salt tolerance and photosynthetic efficiency

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Yu-Chang Tsai ◽  
Kuan-Chuan Chen ◽  
Tung-Shan Cheng ◽  
Chuan Lee ◽  
Shih-Hung Lin ◽  
...  
Keyword(s):  
Chlorophyll Fluorescence ◽  
Salt Tolerance ◽  
Salinity Stress ◽  
Genetic Architecture ◽  
Photosynthetic Efficiency ◽  
Photosynthetic Performance ◽  
Cultivated Rice ◽  
Rice Varieties ◽  
Chlorophyll Fluorescence Parameters ◽  
Fluorescence Parameters

Abstract Background Photosynthetic efficiency might be a key factor determining plant resistance to abiotic stresses. Plants can sense when growing conditions are not favorable and trigger an internal response at an early stage before showing external symptoms. When a high amount of salt enters the plant cell, the membrane system and function of thylakoids in chloroplasts could be destroyed and affect photosynthetic performance if the salt concentration is not regulated to optimal values. Oryza species have salt-tolerant and salt-sensitive genotypes; however, very few studies have investigated the genetic architecture responsible for photosynthetic efficiency under salinity stress in cultivated rice. Results We used an imaging-based chlorophyll fluorometer to monitor eight rice varieties that showed different salt tolerance levels for four consecutive days under control and salt conditions. An analysis of the changes in chlorophyll fluorescence parameters clearly showed the maximum quantum efficiency of PSII in sensitive varieties was significantly reduced after NaCl treatment when compared to tolerant varieties. A panel of 232 diverse rice accessions was then analyzed for chlorophyll fluorescence under salt conditions, the results showed that chlorophyll fluorescence parameters such as F0 and NPQ were higher in Japonica subspecies, ΦPSII of Indica varieties was higher than that in other subgroups, which suggested that the variation in photosynthetic efficiency was extensively regulated under salt treatment in diverse cultivated rice. Two significant regions on chromosome 5 were identified to associate with the fraction of open PSII centers (qL) and the minimum chlorophyll fluorescence (F0). These regions harbored genes related to senescence, chloroplast biogenesis and response to salt stress are of interest for future functional characterization to determine their roles in regulating photosynthesis. Conclusions Rice plant is very sensitive to salinity stress, especially at young seedling stage. Our work identified the distribution pattern of chlorophyll fluorescence parameters in seedlings leaf and their correlations with salt tolerance level in a diverse gene pool. We also revealed the complexity of the genetic architecture regulating rice seedling photosynthetic performance under salinity stress, the germplasm analyzed in this study and the associated genetic information could be utilized in rice breeding program.

Effect of Branched Broomrape (Orobanche ramosa) Infection on the Growth and Photosynthesis of Tomato

Weed Science ◽  
2008 ◽  
Vol 56 (4) ◽  
pp. 574-581 ◽  
Author(s):  
Giovanni Mauromicale ◽  
Antonino Lo Monaco ◽  
Angela M. G. Longo
Keyword(s):  
Chlorophyll Fluorescence ◽  
Chlorophyll Content ◽  
Photosynthetic Rate ◽  
Carbon Assimilation ◽  
Parasitic Plants ◽  
Chlorophyll Fluorescence Parameters ◽  
Leaf Chlorophyll Content ◽  
Fluorescence Parameters ◽  
Growing Seasons ◽  
Leaf Chlorophyll

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.

Photoinduced toxicity of fluoranthene on primary processes of photosynthesis in lichens

2006 ◽  
Vol 39 (1) ◽  
pp. 91-100 ◽  
Author(s):  
Marie KUMMEROVÁ ◽  
štěpán ZEZULKA ◽  
Jana KRULOVÁ ◽  
Jan TŘÍSKA
Keyword(s):  
Chlorophyll Fluorescence ◽  
Bioconcentration Factor ◽  
Lichen Species ◽  
Chlorophyll Fluorescence Parameters ◽  
Fluorescence Parameters ◽  
Photochemical Processes ◽  
Symbiotic Algae ◽  
Lasallia Pustulata ◽  
Photoinduced Toxicity ◽  
Umbilicaria Hirsuta

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.

scholarly journals Photosynthetic response to nitrogen source and different ratios of nitrogen and phosphorus in toxic cyanobacteria, Microcystis aeruginosa FACHB-905

2016 ◽  
Author(s):  
Guotao Peng ◽  
Zhengqiu Fan ◽  
Xiangrong Wang ◽  
Chen Chen
Keyword(s):  
Chlorophyll Fluorescence ◽  
Algal Blooms ◽  
Freshwater Ecosystems ◽  
Cyanobacterial Blooms ◽  
Photosynthetic Response ◽  
Nitrogen And Phosphorus ◽  
Ammonium Toxicity ◽  
Chlorophyll Fluorescence Parameters ◽  
Fluorescence Parameters ◽  
N Assimilation

<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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