Bulhac Ion

Physiological Particularities of Maize Plants and the Effect of Some Antioxidants Under Conditions of Moderate Drought

Anastasia Ștefîrță, Ion Bulhac, Lilia Brînză, Maria Cocu, Vera Zubareva

ABSTRACT. Complex investigation on the effect of Thiourea, Galmet and Thiogalmet compositions on water status, intensity of photosynthesis, water use efficiency, growth and yield of ‘P458’ maize plants under conditions of natural humidity in field trials was performed. The beneficial effect of seed and foliage pre-treatment with Thiourea, Galmet and, in particular, the new chemical composition Thiogalmet on plants’ biological processes conditioning a better realisation of the physiological processes associated with plant growth and productivity was established. A significantly greater positive impact of Thiogalmet on the optimisation of hydration degree, water retention capacity, stomatal conductance for CO2/H2O, assimilation, water use efficiency, plant growth and productivity was recorded. There was an additive action of Thiourea and Galmet in the composition of the Tiogalmet preparation. Thiogalmet increased the yield per unit area and improved the commercial quality of the grain. Treating plants with Thiourea, Galmet and Thiogalmet ensured a 27.20, 52.08 and 68.20% yield increase, respectively, compared to the plants in the control variant. Therefore, a major effect was registered in the plants treated with the new composition. The obtained information demonstrates the possibility of mitigating the adverse effects of drought on the physiological response and production by applying antioxidants.

Keywords: growth; photosynthesis; physiologically active substances; plants; productivity; resistance; transpiration

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The “Photosynthesis-Growth-Stress Memory” Relationship In Plants Under Conditions of Moisture Fluctuation and Recurrent Drought: Management Options

Anastasia Ştefîrţă, Ion Bulhac, Lilia Brînză, Leonid Voloșciuc, Eduard Coropceanu, Maria Cocu

ABSTRACT. The effect of co-activation of the stress-memory formation potential under repeated drought of Glycine max (Merr.) L. plants was recorded using cytokinin (CK), thiourea (TH) and, especially, complex preparation Polyel. Glycine max plants (Merr.) L. of Moldovitsa, Nadejda and Magia varieties, exposed to two cycles of “drought–rehydration” at the “first trifoliate leaf” and “flowering – pods formation” phases served as test subjects. The tolerance-inducing effect manifests itself by maintaining the content of assimilatory pigments, photosynthesis and growth processes at a significantly higher level. After the restoration of the optimal moisture background, plants pre-treated with CK, TH and the preparation Polyel, which endured moderate stress in the initial stages of ontogenesis, had restored functional processes. The information obtained in this work certainly opens the management perspective of the ability to form stress memory, adaptation and tolerance of plants to the unfavourable fluctuation of humidity and recurrent drought. The management possibilities of plant adaptation and tolerance are discussed.

Keywords: plants; adaptation; resistance; growth; photosynthesis; transpiration; productivity; cytokinin compounds; antioxidant preparation.

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Polyel – Compound with Antioxidant Properties

Anastasia Ștefîrță, Ion Bulhac, Eduard Coropceanu, Lilia Brînză

ABSTRACT. A new complex compound, Polyel, which contains thiourea, macro- and microelements in the form of salts and coordination complexes, as well as vitamins, was obtained and tested. Biological tests were performed in laboratory experiments and in the vegetation complex of the Institute of Genetics, Physiology and Plant Protection. As subjects of investigations served the plants Glycine max (Merr) cultivars L. ‘Deia’, ‘Moldovița’, and ‘Enigma’ varieties, grown in the Mitcherlih vegetation pots with a volume of 40 kg soil and exposed to the drought stress at the phase “flowering – pods formation”. The beneficial effect of Polyel on antioxidant protection systems by reducing the accumulation of malondialdehyde (MDA) and intensifying the activity of antioxidant protection enzymes has been established. Polyel has been shown to be one of the new biologically active chemicals that can be used in agriculture to reduce the negative impact of oxidative stress caused by reactive oxygen species (ROS). The use of Polyel as a physiologically active substance (PAS) with antioxidant proprieties for pre-treatment of seeds and foliar apparatus is much more effective under moderate drought conditions.

Keywords: Polyel; antioxidant; malondialdehyde; antioxidant protection enzymes; drought; soybean.

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