engleski

NUE variation within a panel of selected winter wheat cultivars under South-Eastern European conditions

Nitrogen use efficiency (NUE) in wheat presents one of the most important agro-ecological concerns that affects our environment and levels of grain yield as well as bread-making quality resulting in possible economic gains or losses for both farmers and millers. Having cultivars with high NUE is therefore a desirable trait of a cultivar when prices of nitrogen inputs and environmental risks are rising. NUE by its nature is known to be associated with various genetic, physiological, morphological and developmental characteristics of wheat plant. The objective of this study was to assess and characterize the components of variation controlled by genotype (G), environment (E) and G × E interaction and relationship among analysed traits. In the present study, we tested 48 winter wheat cultivars from different breeding programs in region in a replicated field trials at three locations (Osijek, Poreč and Zagreb), Croatia in 2016/2017 and 2017/2018 year at two nitrogen levels applied in top-dressing (0 and 100 kg of N/ha). For grain yield and grain protein content all sources of variation were significant except for Genotype × N level with almost undetectable contribution. Other contributions were estimated 4.29 % for ENV × NLEV (Environment × N level), 18.6 % for GEN (genotype) effects, 5.28 % for GEN × ENV (genotype × environment effects) and 55.73 % for ENV (environmental effects). In similar way, for grain protein content (GPC) contribution from these sources of variation were: 10.66 % for ENV × NLEV, 33.47 % for GEN, 7.29 % for GEN × ENV and 38.27 % for ENV. For NUE and its components nitrogen uptake efficiency (NUPE) and nitrogen utilization efficiency (NUTE), among different sources of variation, the most important were the effects of ENV (NUE-38.04 %, NUPE-60.60 % and NUTE- 45.89 %), ENV × NLEV effects (NUE-32.07 %, NUPE-24.27 % and NUTE-8.78 %), GEN effects ((NUE-11.87 %, NUPE-2.52 % and NUTE-23.56 %). Less pronounced effects were found GEN × ENV (NUE-3.82 %, NUPE-1.77 % and NUTE-6.97 %) and Genotype × NLEV (NUE-3.67 %, NUPE-0 % and NUTE- 0.29 NS %). Significant phenotypic correlations were found between grain yield with NUTE (rP=0.32*) and GPC (rP= -0.30*), GPC and NUPE (rP=0.45***) and between NUTE (rP=-0.39*) with NUPE (rP=0.59***) and NUTE (rP=0.50***). Estimated genetic correlations between two N levels were for grain yield (rG=1.04±0.02), GPC (rG=0.99±0.01), NUE (rG=0.99±0.01), NUPE (rG=1.32±0.21) and NUTE (rG=1.01±0.021).

NUE, genetic variation, correlations, wheat, yield

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