Variability and heritability of nitrogen nutrition efficiency indicators in winter wheat

Considering the very important role of nitrogen in plant life cycle, parameters of plant nitrogen nutrition efficiency represent a group of physiological traits suitable to contemporary wheat breeding aims. Therefore, the objectives of the study were to estimate variability of nitrogen nutrition efficiency indicators and to estimate their heritability in wheat. The experiment included 30 wheat cultivars and experimental lines, originating from Serbia: Small Grains Research Center and Institute of Field and Vegetable Crops, Novi Sad. The variability and broad - sense heritability of total nitrogen accumulation (ANt) at maturity, grain harvest index (GIII) and physiological efficiency of nitrogen (PEN) were analysed. The years when the researches were carried out had a highly significant effect on all tested indicators, as well as genotype and interaction year x genotype. Total nitrogen accumulation in mature plant was the most variable indicator (Cv 13.91%), while lower variability was registered for nitrogen harvest index and physiological efficiency of nitrogen (5.81% and 5.59% respectively). NHI heritability was lower (0.52) compared to the ANt and PEN (0.66 and 0.69, respectively). On the other hand, heritability of ANt and PEN were almost the same, but PEN was more repeatable than the ANt.