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Sirvi Autor "Esmaeilzadeh Salestani, Keyvan" järgi

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  • Pisipilt
    Kirje
    Can intercropping alter cereal grains dietary fiber composition?
    (Estonian University of Life Sciences, 2024) Khaleghdoust, Banafsheh; Alaru, Maarika; Korge, Mailiis; Esmaeilzadeh Salestani, Keyvan; Loit-Harro, Evelin; Estonian University of Life Sciences. Institute of Agricultural and Environmental Sciences. Chair of Crop Science and Plant Biology
    Barley and oats are essential cereal grains that contribute to satisfying the consumer's need for dietary fibers, namely arabinoxylans (AX) and beta-glucans (BG). Due to the increasing popularity of intercropping as an environmentally friendly and low-cost approach to sustainable intensification of agriculture and crop production, it is important to understand the relationship between mixed cropping on cereal grains' dietary fiber content. Therefore, the effect of intercropping barley and oat with vetch and field pea was studied compared to pure sown barley and oat on grain AX and BG content in two successive years (2022‒2023). Our result showed that oat had consistently higher AX content while barley demonstrated greater BG content. Intercropping had an influence only on barley grains' BG content, but contrary to our hypothesis, intercropping with vetch decreased the overall concentration of BG when compared to barley pure stand, as vetch was a too competitive partner. We found that grain quality parameters, such as thousand kernel weight and test weight, were positively associated with higher BG content in barley grains. Over a two-year period, weather conditions had an impact only on BG content in intercropped treatments. Increased precipitation decreased BG content in oat and barley in 2022 compared to 2023. Both grains AX content was not affected by intercropping or annual growing conditions.
  • Pisipilt
    Kirje
    Impact of cropping systems on soil microbiome and barley transcriptome
    (Estonian University of Life Sciences, 2023) Esmaeilzadeh Salestani, Keyvan; Loit, Evelin (advisor); Institute of Agricultural and Environmental Sciences; Singh, Jaswinder (opponent)
    Crop production needs to be more sustainable. Farmers are confronted with the challenge to use less nutrients while maintaining food security and other ecosystem services. Therefore, it is essential to examine the agricultural strategies that address sustainability. This dissertation compared the effects of conventional and organic cropping systems on soil biodiversity and gene expression patterns of barley in a five-field crop rotation. Soil DNA analysis showed that all treatments in organic cropping system as well as conventional treatments with low to medium rates of mineral fertilizers increased the diversity and changed the relative abundance of the soil microbiome. Conventional treatment with no added nutrients decreased bacterial and fungal diversity. Yield is important for food security, and thus it is important to understand the processes in the barley plant. The number of differentially expressed genes was higher in conventional treatments, particularly in N2 that received 80 kg of mineral nitrogen per hectare and provided the highest yield, compared to organic treatments. Amide and peptide metabolism and response to acid chemical and inorganic substances were enriched biological processes in studied conventional treatments whereas polysaccharide and glucan metabolic processes were among the dominant biological processes under organic treatments. Expression of ammonium transporters was analysed more precicely over the early stages of crop growth. Up-regulation of HvAMT1;1 started at the anthesis growth stage in the conventional system and its activity had a strong correlation with the nitrogen content of leaves and 1000-kernel weight. Knowledge about the mechanisms being impacted by different nitrogen rates and cropping systems are valuable for agronomists and crop breeders in increasing the sustainability in crop production.