Nitrogen Uptake, Utilisation and Use Efficiency of Different Wheat Species

Abstract

Breeding wheat (Triticum aestivum L.) for high nitrogen use efficiency while maintaining adequate yield, is widely accepted as one of the approaches to maximise farmers’ revenue and minimise pollution risk. However, due to random hybridization events during evaluation and selective breeding for high yield, genetic diversity of existing bread wheat is narrowed down. The present study was conducted to investigate the nitrogen use efficiency and its components of ancient wheat species, a potential source to expand the genetic diversity of bread wheat. Three field experiments were carried out in 2012, 2013 and 2014 at Sutton Bonington Campus, University of Nottingham, UK. Ten genotypes belonging to einkorn, emmer, spelt and modern bread wheat were used as genetic materials of the experiments and three nitrogen levels were compared. Nitrogen uptake efficiency, nitrogen utilisation efficiency and nitrogen use efficiency were calculated at harvest. Nitrogen use efficiency among genotypes varied significantly and bread wheat recorded the highest value followed by spelt, emmer and einkorn. However, in general, nitrogen uptake efficiency was high in emmer and spelt compared to bread wheat. Nitrogen utilisation efficiency of bread wheat was always higher than ancient wheat genotypes resulting in high nitrogen use efficiency. Nitrogen supply has a negative relationship with nitrogen uptake efficiency. According to the results, it can be concluded that ancient wheat genotypes uptake more nitrogen hence high nitrogen uptake efficiency when compared to modern bread wheat. However, the ability to utilise nitrogen in the plants to develop grains is high in modern bread wheat.