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1

Indirect monitoring of root activity in soybean cultivars under contrasting moisture regimes by measuring electrical capacitance

100%

Cseresnyes I., Rajkai K., Takacs T.

Acta Physiologiae Plantarum

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2016

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tom 38

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nr 05

2

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Simultaneous monitoring of electrical capacitance and water uptake activity of plant root system

100%

Cseresnyes I., Takacs T., Fuzy A., Rajkai K.

International Agrophysics

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2014

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tom 28

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nr 4

Pot experiments were designed to test the applicability of root electrical capacitance measurement for in situ monitoring of root water uptake activity by growing cucumber and bean cultivars in a growth chamber. Half of the plants were inoculated with Funneliformis mosseae arbuscular mycorrhizal fungi, while the other half served as non-infected controls. Root electrical capacitance and daily transpiration were monitored during the whole plant ontogeny. Phenology-dependent changes of daily transpiration (related to root water uptake) and root electrical capacitance proved to be similar as they showed upward trends from seedling emergence to the beginning of flowering stage, and thereafter decreased continuously during fruit setting. A few days after arbuscular mycorrhizal fungi-colonization, daily transpiration and root electrical capacitance of infected plants became significantly higher than those of non-infected counterparts, and the relative increment of the measured parameters was greater for the more highly mycorrhizal-dependent bean cultivar compared to that of cucumber. Arbuscular mycorrhizal fungi colonization caused 29 and 69% relative increment in shoot dry mass for cucumbers and beans, respectively. Mycorrhization resulted in 37% increase in root dry mass for beans, but no significant difference was observed for cucumbers. Results indicate the potential of root electrical capacitance measurements for monitoring the changes and differences of root water uptake rate.

3

Reproductive potential of the alien species Asclepias syriaca [Asclepiadaceae] in the rural landscape

100%

Csontos P., Bozsing E., Cseresnyes I., Penksza K.

Polish Journal of Ecology

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2009

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tom 57

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nr 2

383-388

In the beginning of its introduction Common milkweed, Asclepias syriaca L. was used in Hungary as ornamental plant. After escaping from cultivation it has become wide spread during last decades of the 20th century. Nowadays, it covers large areas especially on sandy soils, and its further appearance is expected on dry, deforested and degraded areas. Two neglected fields and one abandoned vineyard were selected. For sampling two quadrates of size 4 m² were used at each stand. The stands were characterized by the following variables: density of stems, percentage of reproductive stems, average number of inflorescences, average number of fruits, fruits per all inflorescences on a stem, pods per fruited inflorescences on a stem, average number of seeds per fruit. In the same quadrates the soil seed bank was studied at two depths (0–5 cm and 5–10 cm). The results showed that the density of stand, percentage of reproductive specimens and average number of fruits were significantly higher on the neglected fields than on the abandoned vineyard. In the neglected fields large number of seeds were detected in the upper soil-layer (2.7– 18.6 × 10³ seeds m⁻²), but in the lower soil-layer much fewer seeds were found and only in one of the fields. Common milkweed seeds were almost completely missing from both soil layers of the abandoned vineyard. However, the seeds recovered from the soils practically did not germinated, indicating that seeds of earlier years sets have lost viability, i.e. the studied stands of A. syriaca did not form a persistent soil seed bank. Nevertheless, the fresh seed production of the neglected field populations, that can reach 7–10 thousands seeds m⁻², may cause a very strong propagulum load not only in the site but also on the surrounding areas.

4

Role of phase angle measurement in electical impedance spetroscopy

100%

Cseresnyes I., Rajkai K., Vozary E.

International Agrophysics

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2013

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tom 27

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nr 4

Importance of phase angle measurement during the application of electrical impedance spectroscopy was studied by executing pot experiments with maize. Electrical impedance, phase angle (strength of capacitive character), and dissipation factor in the plant-soil system were scanned between 100 and 10 000 Hz current frequency. The frequency-dependent change in the phase angle could be described by optimum curves culminating within 920-3 650 Hz. Since the rate of energy dissipation is independent of root extent, the higher phase angle and lower energy dissipation were associated with the higher coefficient of determination achieved for the root electrical impedance – root system size (root dry mass and root surface area) regressions. The characteristic frequency selected on the basis of phase angle spectra provided a higher significance level at statistical comparison of plant groups subjected to stress conditions influencing root development. Due to the physicochemical changes observable in aging root tissue, the apex of phase angle spectra, thus the characteristic frequency, shifted continuously toward the higher frequencies over time. Consequently, the regularly repeated phase angle measurement is advisable in time-course studies for effective application of the electrical impedance method, and the systematic operation at the same frequency without determination of phase angle spectra should be avoided.

5

Influence of substrate type and properties on root electrical capacitance

100%

Cseresnyes I., Vozary E., Kabos S., Rajkai K.

International Agrophysics

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2020

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tom 34

|

nr 1

6

Does electrical capacitance represent roots in the soil?

100%

Cseresnyes I., Vozary E., Rajkai K.

Acta Physiologiae Plantarum

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2020

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tom 42

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nr 05

7

Monitoring of herbicide effect in maize based on electrical measurements

76%

Cseresnyes I., Fekete G., Vegh K. R., Szekacs A., Mortl M., Rajkai K.

International Agrophysics

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2012

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tom 26

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nr 3

8

Electrical characterization of the root system: a noninvasive approach to study plant stress responses

76%

Cseresnyes I., Takacs T., Sepovics B., Kovacs R., Fuzy A., Paradi I., Rajkai K.

Acta Physiologiae Plantarum

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2019

|

tom 41

|

nr 10

A pot experiment was designed to demonstrate that the parallel, single-frequency detection of electrical capacitance (CR), impedance phase angle (ΦR), and electrical conductance (GR) in root–substrate systems was an adequate method for monitoring root growth and some aspects of stress response in situ. The wheat cultivars ‘Hombar’ and ‘TC33’ were grown in a rhyolite-vermiculite mixture under control, and low, medium, and high alkaline (Na₂CO₃) conditions with regular measurement of electrical parameters. The photochemical efficiency (Fv/Fm) and SPAD chlorophyll content were recorded non-intrusively; the green leaf area (GLA), shoot dry mass (SDM), root dry mass (RDM), and root membrane stability index (MSI) were determined after harvest. CR progressively decreased with increasing alkalinity due to impeded root growth. Strong linear CR–RDM relationships (R² = 0.883–0.940) were obtained for the cultivars. Stress reduced |ΦR|, presumably due to the altered membrane properties and anatomy of the roots, including primarily enhanced lignification. GR was not reduced by alkalinity, implying the increasing symplastic conductivity caused by the higher electrolyte leakage indicated by decreasing root MSI. Fv/Fm, SPAD value, GLA, and SDM showed decreasing trends with increasing alkalinity. Cultivar ‘TC33’ was comparatively sensitive to high alkalinity, as shown by the greater relative decrease in CR, SDM, and RDM under stress, and by the significantly lower MSI and higher (moderately reduced) |ΦR| compared to the values obtained for ‘Hombar’. Electrical root characterization proved to be an efficient non-intrusive technique for studying root growth and stress responses, and for assessing plant stress tolerance in pot experiments.

9

Prediction of wheat grain yield by measuring root electrical capacitance at anthesis

76%

Cseresnyes I., Miko P., Kelemen B., Fuzy A., Paradi I., Takacs T.

International Agrophysics

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2021

|

tom 35

|

nr 2

10

Selection of plant physiological parameters to detect stress effects in pot experiments using principal component analysis

64%

Fuzy A., Kovacs R., Cseresnyes I., Paradi I., Szili-Kovacs T., Kelemen B., Rajkai K., Takacs T.

Acta Physiologiae Plantarum

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2019

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tom 41

|

nr 05

Appropriate selection and well-timed measurement of plant developmental, morphological and physiological parameters are essential to maximize efficacy and minimize time consumption of experiments. To select for the most sensitive indicators of drought or salt stress, three independent pot experiments with diverse setups were analysed with 20–20 measured parameters. Parameters of plant growth, phenology and symbiotic interactions, visual stress symptoms, photosynthetic activity, nutrient composition and vitality were studied and the result matrices were evaluated with principal component analysis (PCA). Stress effects manifested in PC1 of two experiments and in PC2 of the third one. Traits assumed to be adequate for stress indication were characterized by high PC1 or PC2 loading values. Beside parameters of biomass production, growth and visible stress symptoms, less evident traits e.g. root electrical capacitance, membrane stability index in roots and leaves, relative water content of leaves and SPAD units were identified.

Ograniczanie wyników

Indirect monitoring of root activity in soybean cultivars under contrasting moisture regimes by measuring electrical capacitance

Simultaneous monitoring of electrical capacitance and water uptake activity of plant root system

Reproductive potential of the alien species Asclepias syriaca [Asclepiadaceae] in the rural landscape

Role of phase angle measurement in electical impedance spetroscopy

Influence of substrate type and properties on root electrical capacitance

Does electrical capacitance represent roots in the soil?

Monitoring of herbicide effect in maize based on electrical measurements

Electrical characterization of the root system: a noninvasive approach to study plant stress responses

Prediction of wheat grain yield by measuring root electrical capacitance at anthesis

Selection of plant physiological parameters to detect stress effects in pot experiments using principal component analysis