Screening for Nitrogen Use Efficiency In Mid-Atlantic Soft Red Winter Wheat Using Canopy Spectral Reflectance.

Accurate and reliable high throughput screening of wheat (Triticum aestivum L.) phenotypes very important to improve stress tolerance and yield.  Using canopy spectral reflectance (CSR) to screen wheat germplasm can aid in the selection of lines with improved nitrogen (N use efficiency in early breeding generations.  An elite panel of regionally established germplasm (300 genotypes) was screened for nitrogen use efficiency via CSR under normal and low nitrogen regimes.  Reflectance samples from a representative area (400 cm²) were collected from each plot at stem elongation, booting, heading and grain filling using an Ocean Optics JAZ spectrophotometer.  Wheat phenology by genotype and weather data were collected.  Grain and plant tissue collected post-flowering was analyzed for N content and uptake.  The elite panel will be evaluated for yield, CSR, grain and total plant uptake nitrogen use efficiency (NUE) and grain protein content.  We expect to develop rapid screening tools to assist wheat breeders in their selection of genotypes with increased N and water use efficiency.