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Influence of induced drought on photosynthetic performance in Dactylis glomerata varieties during the early growth stage

Borawska-Jarmułowicz Barbara, Mastalerczuk Grażyna, Dąbrowski Piotr, Tuchowska Żaneta, Kalaji Hazem

Journal of Water and Land Development

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2024

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no. 60

194--208

EN

Drought significantly impacts the growth and yield of forage grasses, particularly its effect on Dactylis glomerata photosynthetic apparatus during the initial phase of development remains largely unknown. This study investigated the effects of drought on physiological parameters of various D. glomerata varieties. The seedlings obtained after seed germination under optimal and simulated drought conditions by PEG 6000 (three variants) were planted in small pots filled with garden substrate. Over a span of 42 days, the plants were initially kept well-watered (70% capillary water capacity, CWC), after which half of the seedlings from each variant were subjected to drought. This drought stress was applied during the tillering phase for 12 days. Subsequently, the plants were rehydrated (at 70% CWC) and allowed to recover for 14 days. Throughout both drought and recovery periods, measurements were taken. Leaf chlorophyll fluorescence parameters were assessed, and the JIP-test analysis was utilised to provide detailed insights into the functionality of D. glomerata photosynthetic apparatus under drought stress and post-recovery conditions. Several parameters were identified as indicative of the plants’ sensitivity to drought, such as performance indices PIABS and PItot, along with quantum yield parameters ΨEo, φEo, and φPo. The results highlighted that var. Minora and Tukan exhibited greater tolerance to water deficit when compared to the other varieties studied. They showed a large increases in PIABS and PItot values after drought stress as well as after the re-watering (recovery period) compared to control plants. This suggests their potential for better adaptation to drought conditions.

2

Early detection of phosphorus deficiency stress in cucumber at the cellular level using chlorophyll fluorescence signals

Sieczko Leszek, Dąbrowski Piotr, Kowalczyk Katarzyna, Gajc-Wolska Janina, Borucki Wojciech, Janaszek-Mańkowska Monika, Kowalczyk Waldemar, Farci Domenica, Kalaji Hazem M.

Journal of Water and Land Development

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2022

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Special Issue

176--186

EN

Abiotic stressors contribute to growth restriction and developmental disorders in plants. Early detection of the first signs of changes in plant functioning is very important. The objective of this study was to identify chlorophyll fluorescence parameters that change under phosphorus deficiency stress in cucumber. In this work, a trail to study the early changes caused by phosphorus deficiency in cucumber plants by analysing their photosynthetic performance is presented. Chlorophyll-a fluorescence (ChF) parameters were measured every 7 days for a period of 28 days. Measurements were made separately on young and old leaves and on cucumber fruit. Parameters that decreased during the stress were: p2G, PIabs, PItotal, REo/CSo, and TRo/CSo. P deficiency decreased total electron carriers per RC (ECo/RC), yields (TRo/ABS (Fv/Fm), ETo/TRo, REo/ETo, ETo/ABS and REo/ABS), fluxes (REo/RC and REo/CSo) and fractional reduction of PSI end electron acceptors, and damaged all photochemical and non-photochemical redox reactions. Principal component analysis revealed a group of ChF parameters that may indicate early phosphorus deficiency in cucumber plants. Our results are used in the discovery of sensitive bioindicators of phosphorus deficiency in cucumber plants. Most JIP test parameters are linked to mathematical equations, so we recommend using of advanced statistical tools, such as principal component analysis, which should be considered very useful for stress identification. It has also been shown to be more effective in multivariate methods compared to univariate statistical methods was demonstrated.

3

Biometric indicators of growth and development of Lolium perenne and Trifolium repens in terms of recultivation of soil contaminated with petroleum

Pawluśkiewicz Bogumiła, Małuszyńska Ilona, Małuszyński Marcin, Dąbrowski Piotr, Gnatowski Tomasz

Journal of Water and Land Development

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2022

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Special Issue

70--79

EN

The aim of the research was to determine the factors defining the growth and development of Lolium perenne and Trifolium repens upon petroleum contamination. The top layer of clay soil contaminated with petroleum products resulting from an oil pipeline failure was collected for the tests. The control was the same type of uncontaminated soil with the addition of, under laboratory conditions, tissue paper. The research was conducted in two stages. The first concerned the germination process and seedlings parameters (Petri dishes). The germination energy (GE) and the germination capacity (GC) of seeds were determined. The seedling’s development was also evaluated based on ‘WinRhizo PRO 2009’ software. Then, in the second stage, pot tests were carried out, where the growth and development of species in the first year after sowing were temporarily measured. The parameters studied were the number, height, green and dry masses of the plants. A Gompertz regression model describing seed species germination and number species as time dependent dynamic was applied. The data were analysed statistically using variance analysis (ANOVA) and the PCA (principal component analysis) method. The results of our study indicated that admixture of petroleum into the soil does not seriously affect the development dynamics of Lolium perenne seedlings. The diesel oil contamination mostly affects the germination of the Trifolium repens by a statistically significant increase of the maximum value of germination and increasing the maximum growth rate.

4

Tribological Properties of Medium-Carbon Steel after Nitriding Combined with Subsequent Oxidation and Impregnation

Kasprzycka Ewa, Bogdański Bogdan, Dąbrowski Piotr

Tribologia

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2019

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nr 1

13--18

EN

The paper presents the results of examinations of tribological and corrosion properties of the layers produced on a C45 medium-carbon steel surface in the gas nitriding process combined with subsequent treatment – oxidation and impregnation of corrosion inhibitor. Investigations of the microstructure of these layers and their phase composition were carried out. Hardness of the layers was measured by Vickers method. Tribological properties (linear wear) of the layers were performed by means of the three-cylinder-cone method. Resistance to corrosion was determined by electrochemical methods. The investigations showed that the linear wear of the C45 steel samples with the layers produced in the combined processes of nitriding with subsequent oxidation and impregnation was smaller than that of steel samples without layers. Moreover, the corrosion resistance of these layers in aggressive solutions containing chloride ions was very good.

PL

W pracy omówiono wyniki badań właściwości tribologicznych i korozyjnych warstw wytwarzanych na powierzchni stali średniowęglowej C45 w procesie azotowania gazowego połączonym z następną obróbką – utlenianiem i impregnacją inhibitorem korozji. Przeprowadzono badania mikrostruktury tych warstw, jak również ich składu fazowego. Twardość warstw była mierzona metodą Vickersa. Właściwości tribologiczne (zużycie liniowe) warstw oceniano metodą trzy wałeczki–stożek. Badania odporności na korozję przeprowadzono metodami elektrochemicznymi. Badania wykazały, że zużycie liniowe próbek ze stali C45 z warstwami wytworzonymi w połączonych procesach azotowania z następnym utlenianiem i impregnacją, było mniejsze niż próbek ze stali bez warstw. Ponadto odporność korozyjna tych warstw w agresywnych roztworach zawierających jony chlorkowe była bardzo dobra.

5

Księga rozproszona, czyli blockchain w praktyce

Dąbrowski Piotr

Logistyka

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2019

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nr 3

52--53

PL

Blockchain to technologia, która błyskawicznie zdobywa popularność. Daje ogromne możliwości, jednocześnie jest tania i odporna na cyberataki.

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Mercury Content in Upper Layers of Soils from the Areas with Various Impacts of Anthropogenic Pressure

Małuszyński Marcin J., Dąbrowski Piotr, Małuszyńska Ilona

Journal of Ecological Engineering

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2019

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Vol. 20, nr 11

13--17

EN

The aim of the conducted research was to determine the mercury content in the upper layers of soil taken from the areas with various impact of anthropogenic pressure. The article presents the content of mercury in the top layers of soils from selected areas of two districts of Warsaw, ie Ursynów and Mokotów. These areas are heavily influenced by the human activity. For comparison, a soil sample was also taken from the area of the Solska Forest, which is an example of an area with a negligible impact of anthropogenic pressure. The mercury content in the analyzed soil samples taken from the area of Warsaw ranged from 0.0334 mg·kg-1 to 0.4004 mg·kg-1 in Ursynów, while the soils from the Mokotów area contained from 0.2320 mg·kg-1 to 1.3098 mg·kg-1. For comparison, the sample from the Solska Forest area contained 0.2544 mg Hg·kg-1. In order to avoid uncontrolled re-emission and, as a consequence, possible accumulation of this element in the environment, it is necessary to continue monitoring the level of mercury pollution, among others, in soil.