hrvatski

Utjecaj medija rasta na biološki aktivne spojeve u biljkama

The maturity and quality of the substrate is most often evaluated by the cultivation of plants by direct sowing into the growing media. The limit of the toxic impact of plant nutrients, in addition to chemical form and concentration, depends on the physico-chemical properties of the growing medium. The aim of this study was to determine the effect of commercial substrate, compost and vermicompost, and their mixtures with commercial substrate in a 1:1 ratio, watered using solutions with 400 or 600 mg NH4+ L-1 on the content of chloroplast pigments, phenols, flavonoids and antioxidant activity. Four plant species were used in the bioassay: garden cress (Lepidium sativum L.), cucumber (Cucumis sativus L.), barley (Hordeum vulgare L.), and wheat (× Triticosecale Wittmack). The plants were grown under controlled conditions for four weeks during which they were watered with deionized water or NH4+ solutions. The growing medium, solutions and their interactions significantly influenced the content of chloroplast pigments. No significant effect of before mentioned treatments on carotenoid content was found in barley. Substrate significantly influenced the phenol content in barley and lettuce, and the interaction medium×solution significantly affect its content in barley and wheat. The content of flavonoids in barley was significantly influenced by the substrate, while their content in salad was significantly influenced by the NH4+ solution. Total antioxidant activity in wheat was significantly influenced by both treatments. The highest value of the antioxidant activity according to DPPH method, was found in wheat grown in commercial substrate (0.023) and lowest in mixtures of compost (0.012) and vermicompost (0.016) with commercial substrate. Higher antioxidant activity was found in wheat watered with deionized water (0.021) compared to watering solutions containing 400 mg NH4+ L-1 (0.016) and 600 mg NH4+ L-1 (0.015).

antioksidativna aktivnost ; fenoli ; flavonoidi ; kloroplastni pigmenti

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