Reflectance and chlorophyll fluorescence-based retrieval of photosynthetic parameters improves the estimation of subtropical forest productivity

ABSTRACT: The objectives of this research were to evaluate the interaction between herbicides mixed with saflufenacil for the control of barnyardgrass and to determine the effect on photosynthetic and chlorophyll fluorescence parameters. The experiment was conducted in a greenhouse in a 2x8 factorial scheme, whose factor A tested resistant and susceptible biotypes; and factor B the herbicides: saflufenacil (70 g a.i. ha-1), clomazone (180 g a.i. ha-1), imazapyr + imazapic (73.5 + 24.5 g a.i. ha-1), and cyhalofop (360 g a.i. ha-1), the mixtures of these herbicides with saflufenacil, and control without treatment. Weed control was assessed 7, 14, 21 and 28 days after herbicide application (DAA), as well as shoot dry matter at 28 DAA, photosynthetic parameters using infrared gas analyzer (IRGA), and emission of chlorophyll a fluorescence after 24 and 28 hours of application of treatments, respectively, and interaction of herbicides. Combination of saflufenacil with the herbicides tested in general did not change the response of both barnyardgrass biotypes to the herbicides used. The resistant biotype showed a lower negative effect on chlorophyll fluorescence and photosynthesis parameters in the combination of herbicides with saflufenacil. The herbicide cyhalofop was effective for the control of ALS-susceptible and resistant barnyardgrass.

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Genotypic Variability of Photosynthetic Parameters in Maize Ear-Leaves at Different Cadmium Levels in Soil

Agronomy ◽

10.3390/agronomy10070986 ◽

2020 ◽

Vol 10 (7) ◽

pp. 986 ◽

Cited By ~ 1

Author(s):

Mario Franić ◽

Vlatko Galić ◽

Zdenko Lončarić ◽

Domagoj Šimić

Keyword(s):

Chlorophyll Fluorescence ◽

Inductively Coupled Plasma ◽

Reaction Centers ◽

Photosynthetic Parameters ◽

Dissipation Energy ◽

Cd Uptake ◽

Chlorophyll Fluorescence Parameters ◽

Maize Genotypes ◽

Quinone Acceptor ◽

Soil Cd

Excess of cadmium (Cd) in soil leads to a number of adverse effects which challenge agricultural production. Aims of this study were to investigate variations in Cd content in leaves (Zea mays L.) of different maize genotypes and to detect effects of Cd on photosynthesis through chlorophyll a fluorescence. Pot vegetation experiments with four maize genotypes and four different soil Cd levels were repeated for two years. Chlorophyll fluorescence, photosynthetic pigments and inductively coupled plasma (ICP) analysis for ear-leaf Cd and zinc (Zn) and soil Cd were carried out. Significant differences between genotypes were found for leaf Cd, where higher Cd soil concentrations resulted in higher Cd leaf concentrations. Cd uptake into maize leaves increased with increasing Cd levels in soil, which was genotype-dependent and higher and lower Cd accumulating groups were formed. Changes in chlorophyll fluorescence caused by elevated Cd levels in soil were mostly visible as changes in dissipation energy, yields of primary photosystem II photochemistry and electron transport. Decrease of reaction centers per antenna chlorophyll and increased variable fluorescence at J step (VJ) resulted in decrease of performance indexes in the highest Cd concentration. Decreases in chlorophyll fluorescence parameters suggest reduced functionality of reaction centers and problems in re-oxidation of primary quinone acceptor (QA).

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The role of potassium phosphite in chlorophyll fluorescence and photosynthetic parameters of downy mildew-challenged cucumber Cucumis sativus plants

Archives of Phytopathology and Plant Protection ◽

10.1080/03235408.2017.1407470 ◽

2017 ◽

Vol 50 (17-18) ◽

pp. 927-940 ◽

Cited By ~ 3

Author(s):

Moazzameh Ramezani ◽

Mahmood Karimi Abdolmaleki ◽

Samira Shabani ◽

Ali Dehestani

Keyword(s):

Chlorophyll Fluorescence ◽

Downy Mildew ◽

Cucumis Sativus ◽

Photosynthetic Parameters ◽

Potassium Phosphite

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Research Note: Measuring variability in chlorophyll-fluorescence-derived photosynthetic parameters in situ with a programmable multi-channel fluorometer

Functional Plant Biology ◽

10.1071/fp03213 ◽

2004 ◽

Vol 31 (5) ◽

pp. 559 ◽

Cited By ~ 8

Author(s):

John W. Runcie ◽

Martin J. Riddle

Keyword(s):

Chlorophyll Fluorescence ◽

Single Channel ◽

Light Response ◽

Photosynthetic Parameters ◽

Effective Quantum Yield ◽

Response Curves ◽

Mean Values ◽

Pam Fluorometer ◽

Relative Electron

A submersible device was constructed for simultaneous in situ measurement of the effective quantum yield of chlorophyll fluorescence (ΔF / Fm′) of eight macroalgal samples. The device incorporated a commercially available PAM fluorometer. Four samples each of the macroalgae Iridaea mawsonii (Lucas) and Monostroma hariotii (Gain) were examined. ΔF / Fm′ and light-response curves (LCs) were regularly applied over 24 h to estimate diel changes in relative electron transport rates and the relative efficiency of photon conversion at low irradiances (α), and the variance attributable to mean values of both ΔF / Fm′ and α were estimated. A second commercial single-channel fluorometer provided an independent measure of variability in LC parameters between individual samples, and the magnitude of this variability was within the range measured with the multi-channel device. Between-sample variability at noon, measured with the multi-channel device, was significantly greater than at other times of the day. ΔF / Fm′ of M. hariotii were not significantly different throughout most of the day except at midnight, when values were significantly higher. In contrast, over 24-h only ΔF / Fm′ of I. mawsonii at noon (growing in low light) was significantly lower. By providing replicate LCs at each time point, the programmable multi-channel fluorometer enables testing of significant differences in photosynthetic parameters over a diel period.

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The Driving Factors of Subtropical Mature Forest Productivity: Stand Structure Matters

Forests ◽

10.3390/f12080998 ◽

2021 ◽

Vol 12 (8) ◽

pp. 998

Author(s):

Siyuan Ren ◽

Qingsong Yang ◽

Heming Liu ◽

Guochun Shen ◽

Zemei Zheng ◽

...

Keyword(s):

Environmental Factors ◽

Stand Structure ◽

Forest Productivity ◽

Subtropical Forest ◽

Tree Size ◽

Above Ground Biomass ◽

Niche Complementarity ◽

Subtropical Forests ◽

Ground Biomass ◽

Size Diversity

Forest productivity (increment of above-ground biomass) is determined by biodiversity but also by stand structure attributes. However, the relative strengths of these drivers in determining productivity remain controversial in subtropical forests. In this study, we analyzed a tree growth data from 500 plots with in a 20 ha mature subtropical forest in eastern China. We used spatial simultaneous autoregressive error models to examine the effects of diversity variables (species richness, evenness, and composition), stand structural attributes (stand density, tree size range and diversity), environmental factors (topography and soil), and initial above-ground biomass (AGB) on productivity. We also applied structural equation models to quantify the relative importance of diversity, stand structure, environmental factors, and initial AGB in determining forest productivity. Our results showed that stand structure together with diversity and initial AGB governed forest productivity. Tree size diversity (DBH Shannon’s diversity index) had the largest positive effect on forest productivity. These results provide new evidence that structural explanatory variables have greater contributions to productivity for mature subtropical forests, strongly supporting the niche complementarity hypothesis. Our work highlights the importance of tree size diversity in promoting high forest productivity, and suggests that regulating and conserving complexity of forest stand structure should be among the most important goals in subtropical forest management.

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Comment on “Impacts of species richness on productivity in a large-scale subtropical forest experiment”

Science ◽

10.1126/science.aav9117 ◽

2019 ◽

Vol 363 (6423) ◽

pp. eaav9117

Author(s):

Hua Yang ◽

Zhongling Guo ◽

Xiuli Chu ◽

Rongzhou Man ◽

Jiaxin Chen ◽

...

Keyword(s):

Species Richness ◽

Tree Species ◽

Large Scale ◽

Forest Productivity ◽

Subtropical Forest ◽

Species Loss ◽

Subtropical China

Huang et al. (Reports, 5 October 2018, p. 80) report significant increases in forest productivity from monocultures to multispecies mixtures in subtropical China. However, their estimated productivity decrease due to a 10% tree species loss seems high. We propose that including species richness distribution of the study forests would provide more meaningful estimates of forest-scale responses.

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A new method to estimate photosynthetic parameters through net assimilation rate−intercellular space CO2 concentration (A −C i ) curve and chlorophyll fluorescence measurements

New Phytologist ◽

10.1111/nph.14260 ◽

2016 ◽

Vol 213 (3) ◽

pp. 1543-1554 ◽

Cited By ~ 18

Author(s):

Dany P. Moualeu-Ngangue ◽

Tsu-Wei Chen ◽

Hartmut Stützel

Keyword(s):

Chlorophyll Fluorescence ◽

Intercellular Space ◽

Co2 Concentration ◽

New Method ◽

Net Assimilation Rate ◽

Photosynthetic Parameters ◽

Assimilation Rate ◽

Fluorescence Measurements ◽

Net Assimilation

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Responses of photosynthetic parameters to drought in subtropical forest ecosystem of China

Scientific Reports ◽

10.1038/srep18254 ◽

2015 ◽

Vol 5 (1) ◽

Cited By ~ 15

Author(s):

Lei Zhou ◽

Shaoqiang Wang ◽

Yonggang Chi ◽

Qingkang Li ◽

Kun Huang ◽

...

Keyword(s):

Forest Ecosystem ◽

Subtropical Forest ◽

Photosynthetic Parameters

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Uniform Water Potential Induced by Salt, Alkali, and Drought Stresses Has Different Impacts on the Seedling of Hordeum jubatum: From Growth, Photosynthesis, and Chlorophyll Fluorescence

Frontiers in Plant Science ◽

10.3389/fpls.2021.733236 ◽

2021 ◽

Vol 12 ◽

Author(s):

Congcong Shi ◽

Fan Yang ◽

Zihao Liu ◽

Yueming Li ◽

Xiaolin Di ◽

...

Keyword(s):

Chlorophyll Fluorescence ◽

Water Potential ◽

Photochemical Efficiency ◽

Photosynthetic Performance ◽

Photochemical Quenching ◽

Photosynthetic Parameters ◽

Alkali Stress ◽

Gas Exchange Parameters ◽

Hordeum Jubatum ◽

Damaging Effects

Hordeum jubatum is a halophyte ornamental plant wildly distributed in the Northeast of China, where the low water potential induced by various abiotic stresses is a major factor limiting plant growth and development. However, little is known about the comparative effects of salt, alkali, and drought stresses at uniform water potential on the plants. In the present study, the growth, gas exchange parameters, photosynthetic pigments, and chlorophyll fluorescence in the seedlings of H. jubatum under three low water potentials were measured. The results showed that the growth and photosynthetic parameters under these stresses were all decreased except for carotenoid (Car) with the increasing of stress concentration, and alkali stress caused the most damaging effects on the seedlings. The decreased net photosynthetic rate (Pn), stomatal conductance (Gs), and intercellular CO2 concentrations (Ci) values under salt stress were mainly attributed to stomatal factors, while non-stomatal factors were dominate under drought and alkali stresses. The reduced chlorophyll and slightly increased Car contents occurred under these stresses, and most significant changed under alkali stress. In addition, the maximum photochemical efficiency (Fv/Fm), actual photochemical efficiency (ΦPSII), and photochemical quenching coefficient (qP) under the stresses were all decreased, indicating that salt, alkali, and drought stresses all increased susceptibility of PSII to photoinhibition, reduced the photosynthetic activity by the declined absorption of light for photochemistry, and increased PSII active reaction centers. Moreover, the non-photochemical quenching coefficient (NPQ) of alkali stress was different from salt and drought stresses, showing that the high pH of alkali stress caused more damaging effects on the photoprotection mechanism depending on the xanthophyll cycle. The above results suggest that the H. jubatum has stronger tolerance of salt than drought and alkali stresses, and the negative effects of alkali stress on the growth and photosynthetic performance of this species was most serious.

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