scholarly journals Anatomy, chlorophyll content and photosynthetic performance in current-year and previous-year Aleppo pine (Pinus halepensis Mill.) needles

2020 ◽  
Vol 44 (1) ◽  
pp. 61-69 ◽  
Author(s):  
Tomo Trstenjak ◽  
Antunovic Dunic ◽  
Selma Mlinaric ◽  
Lidija Begovic ◽  
Marin Skoro ◽  
...  
Keyword(s):  
Chlorophyll Content ◽  
Chlorophyll A ◽  
Pinus Halepensis ◽  
Woody Species ◽  
Photosynthetic Performance ◽  
Aleppo Pine ◽  
Resin Duct ◽  
Chlorophylls A And B ◽  
Crown Defoliation ◽  
Significant Difference

Aleppo pine (Pinus halepensis) is a widespread Mediterranean woody species. Needles usually fall off the tree after the second year, which can be the reason for substantial crown defoliation under extreme environmental stress. The aim of the present investigation was to compare the anatomy, chlorophyll content and photosynthetic performance in current-year (CY) and previous-year (PY) Aleppo pine needles. Chlorophyll concentrations were determined spectrophotometrically, while photosynthetic performance was determined by measuring the increase in chlorophyll a fluorescence (the JIP test). The obtained results revealed that concentrations of chlorophylls a and b were almost twice as great in PY needles as in CY ones. The chlorophyll a to b ratio and values of the maximum quantum yield of photosystem II (Fv/Fm) showed no statistically significant difference between CY and PY needles. However, the performance index (PIABS) was significantly higher in CY needles compared to PY ones. Analysis of PIABS components revealed that CY needles had increased electron transport beyond the primary electron acceptor, QA -, which was associated with a lower value of variable fluorescence at 2 ms (VJ) in comparison with PY needles. Also, some differences were observed in needle anatomy. Current-year needles had an increased proportion of mesophyll tissue, together with decreased proportions of vascular cylinder and resin duct areas. Also, many more starch grains were present in PY than in CY needles. Based on the presented results, it can be concluded that despite considerably lower chlorophyll content, CY needles exhibited photosynthetic performance better than that of older needles, which is an unusual phenomenon in woody species.

Grain yield, dry matter remobilization and chlorophyll content in maize (Zea mays L.) as influenced by nitrogen and water deficit

2018 ◽  
Vol 44 (3) ◽  
pp. 359-356
Author(s):  
Mahta Haghjoo ◽  
Abdollah Bahrani
Keyword(s):  
Zea Mays ◽  
Grain Yield ◽  
Chlorophyll Content ◽  
Water Deficit ◽  
Chlorophyll A ◽  
Dry Matter ◽  
Zea Mays L ◽  
Nitrogen Application ◽  
Significant Difference ◽  
Biological Yield

Out of 20, 40, 60 and 80 per cent moisture depletion 20% showed significantly higher grain yields, biological yield, chlorophyll a, b than the others. However, the highest contribution of stem and leaf dry matter remobilization in grain yield were obtained in 80% moisture depletion and 300 kg N/ha and the lowest one was found in the 20% moisture depletion and 150 kg N/ha. Nitrogen application increased all traits, however there were no significant difference between 250 and 300 kg N/ha.

scholarly journals Chlorophyll content of Thalassia hemprichii (Ehrenberg) Ascherson leaves in some coastal areas of Cebu Island, Central Philippines

2018 ◽  
pp. 35-44
Author(s):  
Lorenzo Halasan ◽  
Danilo Dy
Keyword(s):  
Chlorophyll Content ◽  
Chlorophyll A ◽  
Biomass Productivity ◽  
Nonparametric Tests ◽  
Coastal Areas ◽  
Light Limitation ◽  
Thalassia Hemprichii ◽  
Chl A ◽  
Pigment Extraction ◽  
Significant Difference

Variations in the chlorophyll concentrations in seagrass leaves can be used to indicate biomass, productivity and overall ecosystem condition in coastal areas. In this study, we determined the chlorophyll content (ie chl a and b) of Thalassia hemprichii from selected coastal areas in Cebu Island, Central Philippines to determine if there were spatial variations between intertidal (0m) and subtidal (1.5m) sections, and in the five geographically separate coastal areas of the island. Pigment extraction was done using 95% acetone, the solution analyzed via spectrophotometry and quantified using the equation of Ritchie (2006). The values were statistically compared using nonparametric tests. Mean chlorophyll content and chlorophyll a/b ratio of T. hemprichii showed no significant variations between intertidal and subtidal sections: F(4,45)=27.75, p=0.192 for mean chlorophyll content and F(4,45)=18.28, p=0.116 for chlorophyll a/b ratio. However, there was significant difference between geographic areas (p=0.000). Although T. hemprichii tend to display a physiological response to shading and light limitation, the difference in depth (≈ 1.5m) between intertidal and subtidal sections did not produce a statistically meaningful difference. However, the significant differences between sites for the chlorophyll content and chlorophyll a/b ratio of T. hemprichii could guide future decision in seagrass transplantation of specific localities.

scholarly journals The Effects of Environmental Contaminants on Freshwater Cyanobacteria

2021 ◽  
Author(s):  
◽  
Jenna Mumford
Keyword(s):  
New Zealand ◽  
Quantum Yield ◽  
Chlorophyll A ◽  
Environmental Conditions ◽  
Algal Blooms ◽  
Photosynthetic Performance ◽  
Pigment Content ◽  
Maximum Quantum Yield ◽  
Screening Assay ◽  
Significant Difference

<p>Cyanobacteria are photosynthetic prokaryotes with a cosmopolitan distribution and are key contributors to Earth’s primary production. In favourable conditions, some taxa have the ability to form dense algal blooms. When blooms are created by toxin-producing strains they can become a public health threat and may lead to deaths of wild and domestic animals. Different species and strains respond differently to environmental conditions and contaminants, and this thesis investigates the impacts of natural (microcystin, a hepatotoxic cyanotoxin) and anthropogenic (glyphosate) contaminants on cyanobacteria.  Some non-microcystin-producing cyanobacteria have the ability to sequester microcystin, one of them being the strain Cuspidothrix issatschenkoi CAWBG02, and the reason for this ability is unknown. This strain was supplemented with microcystin in a range of environmental conditions (temperature/light intensity combinations) to determine any impacts on fitness by measuring photosynthetic performance, growth, and pigment content (chlorophyll-a and phycocyanin). Microcystin supplementation at a concentration of 25 μg L-1 did not have an effect on growth or pigment content in C. issatschenkoi, and photosynthetic performance was also largely unaffected. Based on the results from this thesis, C. issatschenkoi does not acquire competitive advantages from microcystin sequestration due to the lack of effects on growth and photosynthetic functioning. Previous research has suggested that microcystin is used to suppress competitors, and a 33% decrease in maximum quantum yield was detected in one environmental condition (low temperature, intermediate light), however, there was no significant difference in all of the other conditions used. Therefore, the results from this study do not support the idea that microcystin is used to suppress competitors. Microcystin sequestration may be more beneficial to non-producing-strains within the same species as the toxin-producer (e.g. non-toxic M. aeruginosa).  Glyphosate and MCPA are two of the most commonly used herbicides in New Zealand and globally. These herbicides enter waterways through leaching and come into contact with non- target species. To determine whether these herbicides have an effect on freshwater cyanobacteria in New Zealand, a screening assay was carried out on fourteen strains. Further, the impacts on pigment content (chlorophyll-a and phycocyanin), growth, and photosynthetic performance in two toxic (Nodularia spumigena, Microcystis aeruginosa) and two non-toxic (Dolichospermum lemmermannii, Microcystis wesenbergii) strains were quantified. Growth rates were not impacted by MCPA in any of the fourteen cyanobacterial strains. Glyphosate impacted growth in seven of the fourteen strains, and response differed between strains even within a single species. In general, strains employing a colonial growth strategy were more tolerant to glyphosate in the screening assay. N. spumigena and M. wesenbergii were unaffected by glyphosate at the concentrations used in the functional analysis, and D. lemmermannii had decreased photosynthetic performance from glyphosate. Intermediate concentrations of glyphosate resulted in promotion of PSII functioning in M. aeruginosa, and high concentrations inhibited maximum quantum yield. The lack of significant impacts on M.wesenbergii and N. spumigena, as well as negative effects of PSII functioning in D. lemmermannii, suggest that glyphosate contamination in freshwaters may benefit toxic M. aeruginosa more than competing toxic and non-toxic species or strains.</p>

Seasonal photosynthesis and anthocyanin production in 10 broadleaf evergreen species

2007 ◽  
Vol 34 (12) ◽  
pp. 1072 ◽  
Author(s):  
Nicole M. Hughes ◽  
William K. Smith
Keyword(s):  
Gas Exchange ◽  
Chlorophyll Content ◽  
Chlorophyll A ◽  
Photosynthetic Capacity ◽  
Photosynthetic Performance ◽  
Evergreen Species ◽  
Maximum Light ◽  
Anthocyanin Pigments ◽  
Anthocyanin Production ◽  
Light Capture

Leaves of many evergreen species turn red when exposed to high sunlight during winter due to production of photoprotective anthocyanin pigments, while leaves of other species, lacking anthocyanin, remain green. Why some evergreen species synthesise anthocyanin pigments while others do not is currently unknown. Furthermore, the relative photosynthetic performance of anthocyanic (red) and acyanic (green) evergreens has yet to be described. Here we present seasonal ecophysiological data for five red and green broadleaf evergreen species. We hypothesise that species which synthesise anthocyanins in winter leaves correspond to those with the most drastic seasonal photosynthetic declines, as reduced energy sinks increase vulnerability to photoinhibition and need for photoprotection. Our results did not support this hypothesis, as gas exchange measurements showed no difference in mean seasonal photosynthetic capacity between red- and green-leafed species. Consistent with anthocyanin’s shading effect, red-leafed species had significantly higher chlorophyll content, lower chlorophyll a/b ratios, and higher maximum light capture efficiency of PSII (Fv/Fm) than green-leafed species during the winter, but not during the summer (when all leaves were green). We conclude that anthocyanin production during winter is likely not associated with diminished photosynthetic capacity, and may simply represent an alternative photoprotective strategy utilised by some species during winter.

scholarly journals The Effects of Environmental Contaminants on Freshwater Cyanobacteria

2021 ◽  
Author(s):  
◽  
Jenna Mumford
Keyword(s):  
New Zealand ◽  
Quantum Yield ◽  
Chlorophyll A ◽  
Environmental Conditions ◽  
Algal Blooms ◽  
Photosynthetic Performance ◽  
Pigment Content ◽  
Maximum Quantum Yield ◽  
Screening Assay ◽  
Significant Difference

<p>Cyanobacteria are photosynthetic prokaryotes with a cosmopolitan distribution and are key contributors to Earth’s primary production. In favourable conditions, some taxa have the ability to form dense algal blooms. When blooms are created by toxin-producing strains they can become a public health threat and may lead to deaths of wild and domestic animals. Different species and strains respond differently to environmental conditions and contaminants, and this thesis investigates the impacts of natural (microcystin, a hepatotoxic cyanotoxin) and anthropogenic (glyphosate) contaminants on cyanobacteria.  Some non-microcystin-producing cyanobacteria have the ability to sequester microcystin, one of them being the strain Cuspidothrix issatschenkoi CAWBG02, and the reason for this ability is unknown. This strain was supplemented with microcystin in a range of environmental conditions (temperature/light intensity combinations) to determine any impacts on fitness by measuring photosynthetic performance, growth, and pigment content (chlorophyll-a and phycocyanin). Microcystin supplementation at a concentration of 25 μg L-1 did not have an effect on growth or pigment content in C. issatschenkoi, and photosynthetic performance was also largely unaffected. Based on the results from this thesis, C. issatschenkoi does not acquire competitive advantages from microcystin sequestration due to the lack of effects on growth and photosynthetic functioning. Previous research has suggested that microcystin is used to suppress competitors, and a 33% decrease in maximum quantum yield was detected in one environmental condition (low temperature, intermediate light), however, there was no significant difference in all of the other conditions used. Therefore, the results from this study do not support the idea that microcystin is used to suppress competitors. Microcystin sequestration may be more beneficial to non-producing-strains within the same species as the toxin-producer (e.g. non-toxic M. aeruginosa).  Glyphosate and MCPA are two of the most commonly used herbicides in New Zealand and globally. These herbicides enter waterways through leaching and come into contact with non- target species. To determine whether these herbicides have an effect on freshwater cyanobacteria in New Zealand, a screening assay was carried out on fourteen strains. Further, the impacts on pigment content (chlorophyll-a and phycocyanin), growth, and photosynthetic performance in two toxic (Nodularia spumigena, Microcystis aeruginosa) and two non-toxic (Dolichospermum lemmermannii, Microcystis wesenbergii) strains were quantified. Growth rates were not impacted by MCPA in any of the fourteen cyanobacterial strains. Glyphosate impacted growth in seven of the fourteen strains, and response differed between strains even within a single species. In general, strains employing a colonial growth strategy were more tolerant to glyphosate in the screening assay. N. spumigena and M. wesenbergii were unaffected by glyphosate at the concentrations used in the functional analysis, and D. lemmermannii had decreased photosynthetic performance from glyphosate. Intermediate concentrations of glyphosate resulted in promotion of PSII functioning in M. aeruginosa, and high concentrations inhibited maximum quantum yield. The lack of significant impacts on M.wesenbergii and N. spumigena, as well as negative effects of PSII functioning in D. lemmermannii, suggest that glyphosate contamination in freshwaters may benefit toxic M. aeruginosa more than competing toxic and non-toxic species or strains.</p>

Estimation of chlorophyll content by absorption spectra of native Spirulina platensis cells

2020 ◽  
pp. 25-33
Author(s):  
Leonid E. Paramonov
Keyword(s):  
Chlorophyll Content ◽  
Chlorophyll A ◽  
Absorption Spectra ◽  
Spirulina Platensis ◽  
Intracellular Concentration ◽  
Absorption Coefficients

A method for retrieving the absorption coefficients of Spirulina platensis pigments using absorption spectra of native cells and excluding the use of extracts is considered. Estimates of the intracellular concentration of chlorophyll a, С-phycoerythrin, С- phycocyanin and allophycocyanin in native cells are discussed.

Tree ring to climate relationships of Aleppo pine (Pinus halepensis Mill.) in Greece

2001 ◽  
Vol 27 (1) ◽  
pp. 89-98 ◽  
Author(s):  
Andreas Papadopoulos ◽  
Françoise Serre-Bachet ◽  
Lucien Tessier
Keyword(s):  
Tree Ring ◽  
Pinus Halepensis ◽  
Aleppo Pine

Frost hardening and resistance in three Aleppo pine (Pinus halepensis Mill.) provenances

2001 ◽  
Vol 49 (3) ◽  
pp. 179-186
Author(s):  
ELENA PAOLETTI ◽  
ROBERTO CALAMASSI ◽  
SARA STRATI
Keyword(s):  
Pinus Halepensis ◽  
Aleppo Pine ◽  
Frost Hardening

Light-Induced Accumulation and Stability of Chlorophylls and Chlorophyll-Proteins during Chloroplast Development in Radish Seedlings

1981 ◽  
Vol 36 (5-6) ◽  
pp. 421-430 ◽  
Author(s):  
H. K. Lichtenthaler ◽  
G. Burkard ◽  
G. Kuhn ◽  
U. Prenzel
Keyword(s):  
Chlorophyll A ◽  
Early Stage ◽  
Continuous Darkness ◽  
Suitable Parameter ◽  
Chlorophyll Accumulation ◽  
Chlorophylls A And B ◽  
Sds Page ◽  
Chlorophyll Protein ◽  
Chlorophyll A And B ◽  
Radish Seedlings

Abstract Illumination of 3 day old etiolated radish seedlings with continuous white light results in a progressive accumulation of chlorophyll a and b. Both pigments are bound in a different way to the thylakoid chlorophyll-proteins, which appear parallel to the formation of chlorophylls. By applying the SDS-PAGE method to SDS-digested chloroplasts, it was possible to show that the chloroplasts of radish cotyledons contain the typical chlorophyll proteins LHCP1-3, CPa, CPI and CPIa which have been found in other plants. Between LHCP1 and CPI an additional chlorophyll protein is detected with the spectral properties of a LHCP; it is termed here LHCPy. When the green plants are transferred to continuous darkness, chlorophylls and the chlorophyll-proteins are progressively degraded. At an early stage of greening chlorophyll b is destroyed at a much higher rate in darkness than chlorophyll a, which yields high chlorophyll a/b ratios. This is paralleled by a faster decrease in the level of the corresponding chloro­phyll a/b-protein LHCP3 than of CPI. At a later stage of greening, after the end of the logarithmic chlorophyll accumulation, the chlorophylls a and b and also the LHCP3 and CPI are destroyed in continuous darkness at equal rates; the a/b ratios and the LHCP3/CPI ratios are then little different from the light control. The data indicate that at an early stage of greening the light-harvesting chlorophyll a/b-protein LHCP3 is less stable than the other chlorophyll-proteins (CPI, CPIa, CPa), which contain pre­ dominantly chlorophyll a. The ratio chlorophyll a to β-carotene (a/c ratio) of CPIa, CPI and CPa is about 10, while that of the LHCP1-3 is found to be between 150 to 300. We therefore propose using the a/c ratio to define the chlorophyll-proteins which, besides the absorption spectra, is the most suitable parameter.

Sign in / Sign up

Export Citation Format

Share Document