scholarly journals Morphological and Physiological Responses of Pinus massoniana Seedlings to Different Light Gradients

Forests ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 523
Author(s):  
Haoyun Wang ◽  
Feng Wu ◽  
Min Li ◽  
Xiaokun Zhu ◽  
Changshuang Shi ◽  
...  
Keyword(s):  
Chlorophyll Fluorescence ◽  
Light Intensity ◽  
Stress Resistance ◽  
Critical Factor ◽  
Pinus Massoniana ◽  
Seedling Height ◽  
Sod Activity ◽  
Chlorophyll Fluorescence Parameters ◽  
Photosynthetic Physiology ◽  
Yellow Orange

Light intensity is a critical factor regulating photosynthetic capacity in plants. However, the effects of varying light intensity on morphological and photoprotective mechanisms in Pinus massoniana seedlings have not been explored in depth, especially those in the first seedling growing season. We measured the growth, photosynthetic physiology, biochemistry, and chlorophyll fluorescence of P. massoniana seedlings at four light gradients: 100% relative irradiance (RI, full sunlight), 70% RI, 50% RI, and 20% RI. The seedling height at 70% RI was 9.27% higher than that at 100% RI. However, seedling height was inhibited under low light intensity; at 20% RI, all seedlings died. The decreasing light intensity inhibited ground diameter growth but increased the height-diameter ratio. The secondary needle emergence rate was 53.4% higher at 70% RI than at 100% RI but was only 2% at 50% RI. The chlorophyll and carotenoid contents increased significantly with decreasing light intensity. The increased Chl b and Car contents promoted the photoreceptor potential of the violet (400~420 nm), blue (440~480 nm), and yellow-orange (597~655 nm) regions in leaves. Among the chlorophyll fluorescence parameters, Fv/Fm, Fv′/Fm′, Y(II), qp, and ETR all reached maximum values at 70% RI but were significantly lower at 50% RI than at 100% RI. However, decreasing the light intensity caused a reduction in NPQ. The 70% RI level increased POD and SOD activity and the contents of osmotic regulation substances and slowed MDA accumulation. Seedlings at 70% RI had a higher growth rate, higher photosynthetic activity and potential, and significantly greater stress resistance than the other seedlings. Therefore, appropriate shading measures were beneficial to the cultivation of vigorous seedlings. Furthermore, spectral reflectance indexes were found to be a suitable tool for monitoring the photosynthetic physiological characteristics, stress resistance characteristics, and growth status of P. massoniana seedlings in real time.

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 Variation in Photosynthetic Traits and Correlation with Growth in Teak (Tectona grandis Linn.) Clones

Forests ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 44 ◽  
Author(s):  
Guihua Huang ◽  
Kunnan Liang ◽  
Zaizhi Zhou ◽  
Guang Yang ◽  
Enarth Muralidharan
Keyword(s):  
Genetic Variation ◽  
Chlorophyll Fluorescence ◽  
Gas Exchange ◽  
Growth Traits ◽  
Tectona Grandis ◽  
Field Trials ◽  
Seedling Height ◽  
Chlorophyll Fluorescence Parameters ◽  
Individual Volume ◽  
Improvement Programs

In order to interpret the patterns of genetic variation of photosynthesis and the relationships with growth traits within gene resources of teak (Tectona grandis Linn.), gas exchange, and chlorophyll fluorescence parameters, growth traits of plants in nursery and field trials were measured for 20 teak clones originated from different countries. The results show that there was abundant genetic variation in gas exchange, chlorophyll fluorescence, and growth among the teak clones. The measured traits were found to have generally high heritability (h2) except for intercellular concentration of carbon dioxide (CO2) (Ci). The net photosynthetic rate (Pn), seedling height, and individual volume of wood were significantly correlated with each other, and seedling height was significantly correlated with plant height in field trials, suggesting that Pn and seedling height can be useful in teak breeding. Teak clones 7029, 71-5, 7219, 7412, and 7122, and provenances 3070, 3074, and 3071 had higher photosynthetic rates, and can be regarded as a key resource in teak improvement programs. This work provides useful information for teak breeding and germplasm resource management.

scholarly journals Shade effects on growth, photosynthesis and chlorophyll fluorescence parameters of three Paeonia species

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9316 ◽  
Author(s):  
Yingling Wan ◽  
Yixuan Zhang ◽  
Min Zhang ◽  
Aiying Hong ◽  
HuiYan Yang ◽  
...  
Keyword(s):  
Chlorophyll Fluorescence ◽  
Light Intensity ◽  
Shade Tolerance ◽  
Low Light ◽  
Chlorophyll Fluorescence Parameters ◽  
Herbaceous Peony ◽  
Fluorescence Parameters ◽  
Low Light Intensity ◽  
Solar Greenhouse ◽  
Greenhouse Cultivation

Insufficient light intensity inhibits the growth of cultivated herbaceous peony and decreases its economic value. Owing to the increased demand for shade-tolerant herbaceous peony, the selection of appropriate parents for hybridization is essential. Paeonia anomala, Paeonia intermedia and Paeonia veitchii can grow under shade conditions in their natural habitats; however, their photosynthetic capacities under shade have not been studied. In this study, we simulated low light intensity (30% sunlight) and evaluated the morphological, photosynthetic and chlorophyll fluorescence parameters of these three species. Moreover, the shade tolerance of these species as well as two common cultivars (Paeonia lactiflora ‘Da Fugui’, which is suitable for solar greenhouse cultivation, and P. lactiflora ‘Qiao Ling’, which is not suitable for solar greenhouse cultivation) was evaluated. The results showed that under shade, the leaf area of P. anomala and P. intermedia increased, the single flowering period of P. intermedia and P. veitchii was prolonged, and the flower color of P. veitchii faded. With respect to P. anomala, P. intermedia and P. veitchii, shade eliminated the photosynthetic ‘lunch break’ phenomenon and decreased photoinhibition at midday. Furthermore, the maximum photochemical efficiency (Fv/Fm) and maximum primary photochemical yield (Fv/Fo) of photosystem II (PSII) in the three species improved significantly, and their changes in light dissipation were different. The shade tolerance of the tested accessions was in the order P. veitchii > P. intermedia > P. anomala > ‘Da Fugui’ > ‘Qiao Ling’, showing that the three wild species were better adapted to low light intensity than the cultivars. Thus, P. anomala, P. intermedia and P. veitchii could potentially be used in the development of shade-tolerant herbaceous peony cultivars.

Effects of water stress and light intensity on chlorophyll fluorescence parameters and pigments of Aloe vera L.

2016 ◽  
Vol 106 ◽  
pp. 141-148 ◽  
Author(s):  
Saeid Hazrati ◽  
Zeinolabedin Tahmasebi-Sarvestani ◽  
Seyed Ali Mohammad Modarres-Sanavy ◽  
Ali Mokhtassi-Bidgoli ◽  
Silvana Nicola
Keyword(s):  
Chlorophyll Fluorescence ◽  
Water Stress ◽  
Light Intensity ◽  
Aloe Vera ◽  
Chlorophyll Fluorescence Parameters ◽  
Fluorescence Parameters

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.

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>

Sign in / Sign up

Export Citation Format

Share Document