Phenotyping for Physiological Traits Related to Nitrogen Use Efficiency in Wheat

The application of excessive amounts of different nitrogen fertilizers have been affecting the environment through leaching to soil, nitrous oxide emissions due to denitrification, and fossil fuels burning during manufacture and application of the fertilizer. In the meantime, the demand for wheat grain yield increased due to the rapid population growth, consequently production per area has to increase. The majority of modern wheat cultivars that has been planted to fulfill this demand for decades require high amount of nitrogen fertilizers in order to give their maximum yield potential. Exploring for cultivars with physiological traits related to high nitrogen-use efficiency through phenotyping might reduce the environmental impact of nitrogen fertilizers. Crop phenotyping presents important means to explore the physiological principles involved in the control of basic plant functions as well as for selecting superior genotypes. The objective of this paper is to increase knowledge on the phenotypic methods used in selection for nitrogen-use efficiency in wheat, as improving nitrogen-use efficiency became a key factor to sustainably ensure global production increase