RESUMO
In this study, we evaluated the leaf antioxidative responses of three wheat varieties (Srpanjka, Divana, and Simonida) treated with two different forms of zinc (Zn), Zn-sulfate and Zn-EDTA, in concentrations commonly used in agronomic biofortification. Zn concentration was significantly higher in the flag leaves of all three wheat varieties treated with Zn-EDTA compared to control and leaves treated with Zn-sulfate. Both forms of Zn increased malondialdehyde level and total phenolics content in varieties Srpanjka and Divana. Total glutathione content was not affected after the Zn treatment. Zn-sulfate increased the activities of glutathione reductase (GR) and guaiacol peroxidase (GPOD) in both Srpanjka and Divana, while glutathione S-transferase (GST) was only induced in var. Srpanjka. Chelate form of Zn increased the activities of GST and GPOD in both Simonida and Divana. Catalase activity was shown to be less sensitive to Zn treatment and was only induced in var. Srpanjka treated with Zn-EDTA where GPOD activity was not induced. Concentrations of Zn used for agronomic biofortification can induce oxidative stress in wheat leaves. The antioxidative status of wheat leaves could be a good indicator of Zn tolerance, whereas wheat genotype and chemical form of Zn are the most critical factors influencing Zn toxicity.
RESUMO
The grain yield and concentrations of Fe, Zn, Se, Cd, and P in two winter wheat genotypes and in vitro bioaccessibility of Fe and Zn under the effect of different nitrogen fertilization and Zn-Se foliar application were evaluated. The total grain Fe, Zn, and Se concentrations, as well as Fe and Zn concentrations, after in vitro digestion were under the strongest effect of foliar Zn-Se application. On the other hand, Fe and Zn bioaccessibility (%) were under the most substantial effect of genotype. Regarding the need to increase concentrations of essential micronutrients in wheat grain, foliar Zn-Se application is a reliable and accepted agricultural practice, but to improve mineral bioaccessibility in human nutrition, foliar Zn-Se application should be combined with the most responsive genotypes. For this reason, further research on the genotype specificity of wheat regarding micronutrient bioaccessibility should be carried out.
RESUMO
In order to investigate the possibility of reducing GHG in winter wheat production, field trial was set up in a 3-year experiment (VS) with four different tillage systems (TS) and three N fertilization norms (FN). The tillage systems were CT-conventional tillage, DT-disk harrowing, LT-soil loosening, and NT-no tillage system. N fertilization norms were set to 120, 150 and 180 kg ha-1. Fuel consumption was measured with three-channel valve, and total value of consumption was calculated on total machinery passes according to technological map. Calculation of greenhouse gas (GHG) emissions from winter wheat production were done by BioGrace model (version 4d 2015). GHG emission per ton of yearly raw material was calculated from fertilizers (production and field emissions), seed, plant protection and diesel usage, so the result was expressed in kg CO2eq ha-1 per year. The main properties of research (TS, FN and VS) are showing statistical significance on total GHG emission from winter wheat production. The largest GHG emission had LT tillage system with 261.89 kg CO2eq ha-1 from fuel emission and 2919.22 kg CO2eq ha-1 in total. This tillage system also had highest yield of 7.78 t ha-1. The lowest yield was observed at NT system (6.92 t ha-1), also with the lowest GHG emission from fuel consumption and total production (fuel 118.30 and total 2685.94 kg CO2eq ha-1). Reduced tillage system such as DT can significantly reduce GHG emissions from diesel consumption without having an impact on wheat yield. This study suggests that DT, primarily, and NT can be recommended as convenient agricultural practices conducive to reconstruct an optimal balance between GHG emissions, yields, and N excesses.
