scholarly journals Spectral Composition of Light Affects Sensitivity to UV-B and Photoinhibition in Cucumber

2021 ◽  
Vol 11 ◽  
Author(s):  
Carolina Falcato Fialho Palma ◽  
Victor Castro-Alves ◽  
Luis Orlando Morales ◽  
Eva Rosenqvist ◽  
Carl-Otto Ottosen ◽  
...  
Keyword(s):  
Chlorophyll Fluorescence ◽  
Gas Exchange ◽  
Light Intensity ◽  
Leaf Gas Exchange ◽  
Red Light ◽  
Broad Band ◽  
Green Light ◽  
Light Conditions ◽  
Chlorophyll Fluorescence Parameters ◽  
Psii Photochemistry

Ultraviolet B (UV-B) (280–315 nm) and ultraviolet A (UV-A) (315–400 nm) radiation comprise small portions of the solar radiation but regulate many aspects of plant development, physiology and metabolism. Until now, how plants respond to UV-B in the presence of different light qualities is poorly understood. This study aimed to assess the effects of a low UV-B dose (0.912 ± 0.074 kJ m–2 day–1, at a 6 h daily UV exposure) in combination with four light treatments (blue, green, red and broadband white at 210 μmol m–2 s–1 Photosynthetically active radiation [PAR]) on morphological and physiological responses of cucumber (Cucumis sativus cv. “Lausanna RZ F1”). We explored the effects of light quality backgrounds on plant morphology, leaf gas exchange, chlorophyll fluorescence, epidermal pigment accumulation, and on acclimation ability to saturating light intensity. Our results showed that supplementary UV-B significantly decreased biomass accumulation in the presence of broad band white, blue and green light, but not under red light. UV-B also reduced the photosynthetic efficiency of CO2 fixation (α) when combined with blue light. These plants, despite showing high accumulation of anthocyanins, were unable to cope with saturating light conditions. No significant effects of UV-B in combination with green light were observed for gas exchange and chlorophyll fluorescence parameters, but supplementary UV-B significantly increased chlorophyll and flavonol contents in the leaf epidermis. Plants grown under red light and UV-B significantly increased maximum photosynthetic rate and dark respiration compared to pure red light. Additionally, red and UV-B treated plants exposed to saturating light intensity showed higher quantum yield of photosystem II (PSII), fraction of open PSII centres and electron transport rate and showed no effect on the apparent maximum quantum efficiency of PSII photochemistry (Fv/Fm) or non-photochemical quenching, in contrast to solely red-light conditions. These findings provide new insights into how plants respond to UV-B radiation in the presence of different light spectra.

scholarly journals Waterlogging tolerance evaluation of fifteen poplar clones cultivated in the Jianghan Plain of China

2021 ◽  
Vol 49 (3) ◽  
pp. 12421
Author(s):  
Ruonan GENG ◽  
Xinye ZHANG ◽  
Xiaoping FAN ◽  
Qian HU ◽  
Tianhong NI ◽  
...  
Keyword(s):  
Chlorophyll Fluorescence ◽  
Gas Exchange ◽  
Leaf Gas Exchange ◽  
Survival Rates ◽  
Biomass Accumulation ◽  
Co2 Concentration ◽  
Jianghan Plain ◽  
Waterlogging Tolerance ◽  
Chlorophyll Fluorescence Parameters ◽  
Fluorescence Parameters

To provide references for poplar cultivation in waterlogged prone area of Jianghan Plain of China, the waterlogging tolerance of 15 poplar clones widely cultivated in these areas were evaluated based on their responses to 45-day waterlogging stress followed by 15-day drainage recovery in morphology, growth, biomass accumulation, leaf gas exchange and chlorophyll fluorescence parameters. The results showed that the normal watered seedlings (CK) of the 15 clones grew vigorously during the experiment, and no defoliation and death occurred. For the seedlings under waterlogging treatment (water 10 cm above the soil surface), its morphology changed markedly, including slowing growth, chlorosis and abscission of leaves, development of hypertrophied lenticels and adventitious roots etc. Waterlogging stress significantly inhibited the seedling growth of height and ground diameter, biomass accumulation, as well as leaf gas exchange and chlorophyll fluorescence parameters of the 15 clones with varying degrees. The net photosynthetic rate (Pn), stomatal conductance (Gs), transpiration rate (Tr), intercellular CO2 concentration/ environmental CO2 concentration (Ci/Ca), variable fluorescence (Fv), variable fluorescence/ initial fluorescence (Fv/Fo) and PS Ⅱ primary light energy conversion efficiency (Fv/Fm) decreased gradually with the prolonged waterlogging, and reached their bottom on day 45. During the terminal recovery stage, the leaf gas exchange and chlorophyll fluorescence parameters of the most clones increased, but their recovery abilities were significantly different. At the end of the experiment, the highest survival rates (100%) were observed in DHY, HS-1, HS-2, I-72, I-69, I-63 and NL-895, and the lowest (zero) occurred in XYY. Survival rates of the other clones ranged from 33.33% to 83.33%. Both results of cluster analysis and membership function analysis showed that HS-1, I-69, DHY, NL-895 and HS-2 had the strongest waterlogging tolerance, XYY and HBY were the worst, and the other clones were moderate. These results would provide guidance not only for the selection of cultivated varieties in Jianghan Plain, but also for the selection of hybrid parents for waterlogging resistance breeding.

scholarly journals Effects of Nitrogen Application on Chlorophyll Fluorescence Parameters and Leaf Gas Exchange in Naked Oat

2013 ◽  
Vol 12 (12) ◽  
pp. 2164-2171 ◽  
Author(s):  
Ye-chun LIN ◽  
Yue-gao HU ◽  
Chang-zhong REN ◽  
Lai-chun GUO ◽  
Chun-long WANG ◽  
...  
Keyword(s):  
Chlorophyll Fluorescence ◽  
Gas Exchange ◽  
Leaf Gas Exchange ◽  
Nitrogen Application ◽  
Chlorophyll Fluorescence Parameters ◽  
Naked Oat ◽  
Fluorescence Parameters

Combining Gas Exchange and Chlorophyll Fluorescence to Assess the Adaptability of Medicinal Plant Aesculus chinensis Compared to Two Imported Aesculus Species

2013 ◽  
Vol 726-731 ◽  
pp. 4330-4336
Author(s):  
Hai Yan Fu ◽  
Fu Qiang Song ◽  
Jia Sen Wu ◽  
Xiang Shi Kong ◽  
Dan Dan Qi
Keyword(s):  
Chlorophyll Fluorescence ◽  
Electron Transport ◽  
Gas Exchange ◽  
Tree Species ◽  
Light Energy ◽  
The Other ◽  
Photochemical Quenching ◽  
Chlorophyll Fluorescence Parameters ◽  
Psii Photochemistry

Analysis of gas exchange and determination of chlorophyll fluorescence parameters in leaves of three tree species including Aesculus chinensis, A. octandra and A. hybrida were conducted under field conditions and then comparison was carried out. The results showed that the light compensation point (LCP) was significantly different among the three tree species, of which the LCP of A. chinensis with 12.53 μmol·m-2·s-1 that of the lowest was notable lower than that of the other two species (36.11 and 46.41 μmol·m-2·s-1respectively). On the other hand, the light saturation point (LSP) of the three tree species also showed remarked different and the LSP of A. chinensis was 1475 μmol·m-2·s-1 which was dramatic higher than that of the other two species respective to 1366.67 and 1025 μmol·m-2·s-1. Beside, the maximum net photosynthetic rate (MNPR) was different too, MNPR of A. chinensis was 9.47μmol CO 2·m-2·s-1which was higher than the other two species (5.91 and 2.30 μmol CO 2·m-2·s-1 respectively), indicating A. chinensis had a higher photosynthetic capacity and stronger utilization ability for light energy. Moreover, the electron transport rate (ETR) of A. chinensis was higher than A. octandra and A. hybrida, the ETR of the former was 55.800 that were 1.33 and 1.44 times of the later two respectively. Quantum yield of PSII photochemistry (ФPSII) in A. chinensis was higher than A. octandra and A. hybrida, the ФPSII of the former was 0.470 that were 1.21 and 1.15 times of the later two respectively. Furthermore, the photochemical quenching (qP) of A. chinensis was 0.975 much higher than A. octandra and A. hybrida respective to 1.10 and 1.10 times of the later two respectively. These three photochemical parameters with dramatic different among the three different tree species suggested A. chinensis had a high activity of electron transport and conversion efficiency for light energy.

The effect of nitrogen deficiency on leaf gas exchange and chlorophyll fluorescence parameters in sunflower

Plant Science ◽  
1996 ◽  
Vol 118 (2) ◽  
pp. 177-184 ◽  
Author(s):  
Stefania Ciompi ◽  
Elisa Gentili ◽  
Lucia Guidi ◽  
Gian Franco Soldatini
Keyword(s):  
Chlorophyll Fluorescence ◽  
Gas Exchange ◽  
Leaf Gas Exchange ◽  
Nitrogen Deficiency ◽  
Chlorophyll Fluorescence Parameters ◽  
Fluorescence Parameters

scholarly journals Response of Photosynthesis and Chlorophyll Fluorescence Parameters of Castanopsis kawakamii Seedlings to Forest Gaps

Forests ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 21
Author(s):  
Zhong-sheng He ◽  
Rong Tang ◽  
Meng-jia Li ◽  
Meng-ran Jin ◽  
Cong Xin ◽  
...  
Keyword(s):  
Chlorophyll Fluorescence ◽  
Light Intensity ◽  
Seedling Growth ◽  
Group Treatment ◽  
Control Group ◽  
Low Light ◽  
Chlorophyll Fluorescence Parameters ◽  
Forest Gaps ◽  
Low Light Intensity ◽  
Weak Light

Light is a major environmental factor limiting the growth and survival of plants. The heterogeneity of the light environment after gap formation in forest influences the leaf chlorophyll contents, net photosynthetic rate (Pn), and chlorophyll fluorescence, thus influencing the growth and regeneration of Castanopsis kawakamii seedlings. The aim of this study was to explore the effects of weak light on the photosynthetic physiology of C. kawakamii seedlings in forest gaps and non-gaps. The results showed that (1) the contents of chlorophyll a (Chl-a), chlorophyll b (Chl-b), and total chlorophyll (Chl-T) in forest gaps were lower than in non-gaps. Seedlings tended to increase chlorophyll content to absorb light energy to adapt to low light intensity in non-gap environments. (2) The Pn values of C. kawakamii seedlings in forest gaps were significantly higher than in non-gaps, and forest gaps could improve the seedlings’ photosynthetic capacity. (3) The C. kawakamii seedlings in forest gaps were more sensitive to weak light and control group treatment, especially the tall seedlings, indicating that seedlings require more light to satisfy their growth needs in the winter. The seedlings in non-gaps demonstrated better adaptability to low light intensity. The light intensity was not adequate in weak light conditions and limited seedling growth. We suggest that partial forest selection cutting could improve light intensity in non-gaps, thus promoting seedling growth and regeneration of C. kawakamii more effectively in this forest.

scholarly journals Variations in leaf gas exchange, chlorophyll fluorescence and membrane potential of Medicago sativa root cortex cells exposed to increased salinity: The role of the antioxidant potential in salt tolerance

2018 ◽  
Vol 70 (3) ◽  
pp. 413-423 ◽  
Author(s):  
Mohamed Farissi ◽  
Mohammed Mouradi ◽  
Omar Farssi ◽  
Abdelaziz Bouizgaren ◽  
Cherki Ghoulam
Keyword(s):  
Antioxidant Enzymes ◽  
Salt Stress ◽  
Chlorophyll Fluorescence ◽  
Membrane Potential ◽  
Salt Tolerance ◽  
Gas Exchange ◽  
Medicago Sativa ◽  
Leaf Gas Exchange ◽  
Root Cortex ◽  
Root Cortex Cells

Salinity is one of the most serious agricultural problems that adversely affects growth and productivity of pasture crops such as alfalfa. In this study, the effects of salinity on some ecophysiological and biochemical criteria associated with salt tolerance were assessed in two Moroccan alfalfa (Medicago sativa L.) populations, Taf 1 and Tata. The experiment was conducted in a hydro-aeroponic system containing nutrient solutions, with the addition of NaCl at concentrations of 100 and 200 mM. The salt stress was applied for a month. Several traits in relation to salt tolerance, such as plant dry biomass, relative water content, leaf gas exchange, chlorophyll fluorescence, nutrient uptake, lipid peroxidation and antioxidant enzymes, were analyzed at the end of the experiment. The membrane potential was measured in root cortex cells of plants grown with or without NaCl treatment during a week. The results indicated that under salt stress, plant growth and all of the studied physiological and biochemical traits were significantly decreased, except for malondialdehyde and H2O2 contents, which were found to be increased under salt stress. Depolarization of membrane root cortex cells with the increase in external NaCl concentration was noted, irrespective of the growth conditions. The Tata population was more tolerant to high salinity (200 mM NaCl) and its tolerance was associated with the ability of plants to maintain adequate levels of the studied parameters and their ability to overcome oxidative stress by the induction of antioxidant enzymes, such as guaiacol peroxidase, catalase and superoxide dismutase.

scholarly journals Effects of Yellow, Green, and Different Blue Spectra on Growth of Potato Plantlets In Vitro

HortScience ◽  
2018 ◽  
Vol 53 (4) ◽  
pp. 541-546 ◽  
Author(s):  
Ruining Li ◽  
Wenwen Huang ◽  
Xiaoxiao Wang ◽  
Xiaoying Liu ◽  
Zhigang Xu
Keyword(s):  
Soluble Sugar ◽  
Red Light ◽  
Green Light ◽  
Dry Weight ◽  
Light Conditions ◽  
Health Index ◽  
Yellow Light ◽  
Blade Number ◽  
Potato Plantlets

The objectives of this study were to determine the effects of yellow light (Y), green light (G), and two blue lights (B) at different wavelengths in conjunction with red light (R) on the growth and morphogenesis of potato plantlets in vitro. Randomized nodal explants were cut into 1.0–1.5 cm pieces and were grown under five different light conditions: fluorescent white light (FL); the combined spectra of R, Y, and B at 445 nm (R630B445Y); the combined spectra of R, G, and B at 445 nm (R630B445G); the combined spectra of R, Y, and B at 465 nm (R630B465Y); and the combined spectra of R, G, and B at 465 nm (R630B465G). Morphogenesis and physiological parameters were investigated. The results showed that R630B445Y and R630B465Y increased the fresh weight (FW), dry weight (DW), stem diameter, blade number, leaf area, specific leaf weight (SLW), and the health index of potato plantlets in vitro; root activity increased significantly; and soluble sugar, soluble protein, and starch also increased. The addition of Y to the combined spectra of R and B contributed to the growth, development, and morphogenesis more than the combined spectra of R and B with G, and B at 445 nm was more effective at promoting plant growth than was B at 465 nm.

Sign in / Sign up

Export Citation Format

Share Document