Effects of oak powdery mildew (Erysiphe alphitoides [Griffon and Maubl.] U. Braun and S. Takam.) on photosynthesis of pedunculate oak (Quercus robur L.)

The aim of the present study was to evaluate the effect of one of the most important foliar diseases, powdery mildew, on the leaf physiological traits of Quercus robur L. using chlorophyll a fluorescence parameters in combination with parameters of leaf gas exchange. For this purpose, greenhouse semi-controlled experiment was conducted with 25 one-year-old seedlings kept in optimal conditions, and the same number of seedlings infected with the mentioned pathogen. Measurements were carried out when the coverage of epiphytic micelia visually reached more than 75% of the surface of leaves in the infected seedlings. The results of gas exchange measurement showed that Erysiphe alphitoides (Griffon and Maubl.) U. Braun and S. Takam caused a significant reduction of net photosynthesis (A) and a significant increase in substomatal CO2 concentration (Ci). Furthermore, considering the fast kinetics of chlorophyll a fluorescence, all of the observes parameters were significantly affected by oak powdery mildew. On the other hand, pulse amplitude modulated fluorescence parameters were mildly affected, with only minimal (Fo?) and maximal (Fm?) fluorescence of dark adopted leaves showing significant difference. This study presented the possibility of usage and the effectiveness of chlorophyll a fluorescence parameters in detection the severe stress conditions, on the example of leaves infected with oak powdery mildew over 75%. Some additional studies should be conducted in the future to determine the possibility of usage and the effectiveness of the observed fluorescence parameters of fast kinetics in detection of mild and early stress.

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Chlorophyll a Fluorescence Parameters do not Detect Yield-limiting Injury from Sub-lethal Rates of 2,4-Dichlorophenoxyacetic Acid (2,4-D) in Cotton (Gossypium hirsutum)

Journal of Experimental Agriculture International ◽

10.9734/jeai/2020/v42i130449 ◽

2020 ◽

pp. 34-48

Author(s):

Seth A. Byrd ◽

John L. Snider ◽

Timothy L. Grey ◽

A. Stanley Culpepper ◽

Jared R. Whitaker ◽

...

Keyword(s):

Chlorophyll A ◽

Chlorophyll A Fluorescence ◽

Yield Loss ◽

Block Design ◽

Dichlorophenoxyacetic Acid ◽

Growth Stages ◽

Biologically Relevant ◽

Fluorescence Parameters ◽

Significant Difference ◽

2,4 Dichlorophenoxyacetic Acid

Aims: Determine if the use of novel chlorophyll a fluorescence parameters could be utilized to predict yield loss of cotton exposed to sublethal rates of 2,4-dichlorophenoxyacetic acid (2,4-D) at various growth stages. Study Design: All trials were arranged in a randomized complete block design with four replications. Treatment means were subjected to analysis of variance and linear regression was utilized to determine relationship between chlorophyll a parameters and yield. Place and Duration of Study: University of Georgia Gibbs Farm in Tifton, GA, USA and the Sunbelt Agricultural Exposition in Moultrie, GA, USA during the 2013 growing season. Methodology: Two sublethal rates of 2,4-D were applied to cotton at six distinct growth stages. The rates consisted of 2 g and 40 g ae ha-1 equivalent to 1/421 and 1/21 of the full rate (0.532 kg ae ha-1), respectively. The sublethal rates were applied to cotton at six growth stages, including the four leaf, nine leaf, first bloom, two, four and six weeks after first bloom growth stages. A fluorometer was used to obtain the fluorescence parameters Fv/Fm, ΦEO and PIABS from the uppermost fully expanded leaves at various intervals after 2,4-D exposure. Results: Despite yield losses ranging from 20 – 90% of the non-treated control, no consistent patterns resulted from utilizing fluorescence transients to detect 2,4-D injury and overall instances of significant difference were minimal and typically not biologically relevant. In many cases, treatments exposed to 2,4-D that exhibited yield loss showed evidence of greater photosynthetic efficiency than the non-treated control. In the majority of instances, many of fluorescence parameters measured fell within ranges observed in previous studies in cotton produced under typical or non-stressed conditions. Conclusion: While it has been proven as a valuable tool in other plant screening endeavors, chlorophyll a fluorescence were not able to detect the effects of sub-lethal rates of 2,4-D on cotton, even in instances that resulted in severe yield loss.

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Mapping QTLs for yield components and chlorophyll a fluorescence parameters in wheat under three levels of water availability

Plant Genetic Resources ◽

10.1017/s1479262111000207 ◽

2011 ◽

Vol 9 (2) ◽

pp. 291-295 ◽

Cited By ~ 24

Author(s):

Ilona Czyczyło-Mysza ◽

Izabela Marcińska ◽

Edyta Skrzypek ◽

Małgorzata Chrupek ◽

Stanisław Grzesiak ◽

...

Keyword(s):

Drought Stress ◽

Chlorophyll A ◽

Chlorophyll A Fluorescence ◽

Wheat Yield ◽

Dry Weight ◽

Interval Mapping ◽

Main Stem ◽

Severe Drought ◽

Single Marker Analysis ◽

Fluorescence Parameters

Drought is one of the major factors limiting wheat yield in many developing countries worldwide. Parameters of chlorophyll a fluorescence kinetics under drought stress conditions have been used to characterize dehydration tolerance in wheat. In the present study, a set of 94 doubled haploid lines obtained from Chinese Spring × SQ1 (CSDH), mapped with 450 markers, was evaluated for yield (grain dry weight/main stem ear), number of grains/main stem ear (NG) and chlorophyll a fluorescence parameters (FC) under moderate and severe drought stress, and compared with results for well-watered plants. quantitative trait loci (QTLs) were identified using Windows QTLCartographer version 2.5 software and the results were analysed using single-marker analysis (SMA) and composite interval mapping (CIM). Analysis using SMA and CIM showed mostly similar QTLs for all traits, though more QTLs were identified by SMA than by CIM. The genetic control of yield, NG and FC varied considerably between drought-stressed and non-stressed plants. Although no major QTL co-locations were found for yield and FC using CIM, the co-location of QTLs for NG, yield and Fv/Fm in drought-stressed plants was observed on chromosome 5A using SMA.

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Leaf gas exchange and chlorophyll a fluorescence in soybean leaves infected by Phakopsora pachyrhizi

Journal of Phytopathology ◽

10.1111/jph.12663 ◽

2017 ◽

Vol 166 (2) ◽

pp. 75-85 ◽

Cited By ~ 9

Author(s):

Vinícius Souza Rios ◽

Jonas Alberto Rios ◽

Carlos Eduardo Aucique-Pérez ◽

Patrícia Ricardino Silveira ◽

Aline Vieira Barros ◽

...

Keyword(s):

Gas Exchange ◽

Chlorophyll A ◽

Chlorophyll A Fluorescence ◽

Leaf Gas Exchange ◽

Phakopsora Pachyrhizi ◽

Soybean Leaves

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Low temperature induced modulation of photosynthetic induction in non-acclimated and cold-acclimated Arabidopsis thaliana: chlorophyll a fluorescence and gas-exchange measurements

Photosynthesis Research ◽

10.1007/s11120-018-0588-7 ◽

2018 ◽

Vol 139 (1-3) ◽

pp. 123-143 ◽

Cited By ~ 11

Author(s):

Kumud B. Mishra ◽

Anamika Mishra ◽

Jiří Kubásek ◽

Otmar Urban ◽

Arnd G. Heyer ◽

...

Keyword(s):

Arabidopsis Thaliana ◽

Gas Exchange ◽

Low Temperature ◽

Chlorophyll A ◽

Chlorophyll A Fluorescence ◽

Photosynthetic Induction

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Growth, Gas Exchange, Chlorophyll a Fluorescence, Biomass Accumulation and Partitioning in Droughted and Irrigated Plants of Two Enset (Ensete ventricosum Welw. Cheesman) Clones

Journal of Agronomy ◽

10.3923/ja.2007.499.508 ◽

2007 ◽

Vol 6 (4) ◽

pp. 499-508 ◽

Cited By ~ 7

Author(s):

Solomon Zewdie . ◽

Mats Olsson . ◽

Masresha Fetene .

Keyword(s):

Gas Exchange ◽

Chlorophyll A ◽

Chlorophyll A Fluorescence ◽

Biomass Accumulation ◽

Ensete Ventricosum

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Seasonality and Small Spatial-Scale Variation of Chlorophyll a Fluorescence in Bryophyte Syntrichia ruralis [Hedw.] in Semi-Arid Sandy Grassland, Hungary

Plants ◽

10.3390/plants9010092 ◽

2020 ◽

Vol 9 (1) ◽

pp. 92 ◽

Cited By ~ 1

Author(s):

Ruchika ◽

Zsolt Csintalan ◽

Evelin Ramóna Péli

Keyword(s):

Quantum Yield ◽

Fluorescence Quenching ◽

Spatial Scale ◽

Chlorophyll A ◽

Chlorophyll A Fluorescence ◽

Small Spatial Scale ◽

Variation Trend ◽

Fluorescence Parameters ◽

Semi Arid ◽

Sandy Grassland

Bryophytes face challenges due to global climate change which is leading to in-depth research in monitoring and studying their photosynthetic activity. The aim of this preliminary experiment was to study the seasonal variation trend in the chlorophyll a fluorescence parameters, Fv/Fm (ratio of variable to maximum fluorescence), photochemical fluorescence quenching (qP), photochemical quantum yield of photosystem II (ΦPS II), fluorescence quenching (qN), and non-photochemical quenching (NPQ), in the moss cushions of Syntrichia ruralis [Hedw.] collected from semi-arid sandy dunes for two slopes i.e., north-east (NE) and south-west (SW) direction. Our results showed a seasonal and small-spatial scale variation trend in all chlorophyll fluorescence parameters. These variations are due to different seasonal conditions referring to different degrees of environmental stress. ΦPS II and qP values were maximum in winter and in spring seasons while Fv/Fm, NPQ and qN were maximum in summer. Based on the different exposition of dunes, the SW slope showed increased values of the effective quantum yield of PS II and qP in comparison to the NE slope due to the optimal microclimate conditions for their expansion. These results may refer to the future changing in diversification and coverage of the Syntrichia species in semi-arid sandy grassland due to more effective metabolism in the beneficial microclimatic conditions.

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