engleski

The effect of selection under high and low nitrogen fertilization levels on grain yield and quality of winter wheat

Nitrogen fertilization (N) increases grain yield and quality, but also represents a significant production cost and has a negative impact on the environment. Therefore, the plant breeders aim to create cultivars with higher N use efficiency. Breeding of N-efficient cultivars can be conducted either directly under N stress or indirectly under optimal conditions. Direct selection in the target environment is advantageous if a crossover interaction between genotype and production system can be detected (Ceccarelli, 1996). The aim of this study was to compare the effect of selection conducted at high (HN) and low (LN) levels of N fertilization on yield and indirect bread-making quality traits of winter wheat. Selection for increased protein content and grain yield was conducted in 2012/2013 selection trial among F6 progenies of two crosses, Golubica × Emesse (G×E) and Verbunkos × Soissons (V×S). Out of 50 evaluated progenies 11 were selected from each cross at both LN and HN. The effect of selection was evaluated in F7 generation grown in 2013/2014 evaluation trial at both N fertilization levels. The difference in the amount of N between the HN and LN was 100 kg/ha in both selection and evaluation trial. ANOVA revealed a significant effect of evaluation N level (N) on grain N yield (GNY), grain protein content (GPC), Zeleny sedimentation value (ZSV) and wet gluten content (WGC) for both crosses and on grain yield (GY) for the cross V×S. Selection N level (Sel) significantly affected GY, GNY, GPC, ZSV and WGC of the cross V×S, while the N×Sel interaction was not detected. Averaged over selection N levels and crosses GY, GPC, GNY, ZSV and WGC were 6%, 7%, 12%, 14% and 9% lower under LN-evaluation conditions than under HN-evaluation conditions, respectively. On the other hand the gluten index (GI) an Pelshenke value (PV) had 6% and 3% higher mean values under LN-evaluation conditions, but the differences were not significant. Averaged over evaluation N levels F7 progenies of the cross V×S produced through HN-selection had 12% higher GY, 4% higher GPC, 8% higher GNY and 10% higher WGC than F7 progenies produced through LN-selection with a higher response at LN evaluation level. For the cross G×E differences between two selection levels were not significant for all traits.The results indicate that selection conducted at high N level is more efficient than selection conducted at low N level in improving grain yield as well as quality traits when breeding for both high-N and low-N conditions.

wheat ; fertilization ; quality ; selection

nije evidentirano