Nitrogen use efficiency of selected winter oat lines grown in flowing solution culture.

Seedlings of nine selected winter oat varieties and lines were grown under controlled conditions in hydroponics for 31 days and then were subjected to two nitrogen steady state treatments high 50 µM and low 2 µM nitrate using 15N for a further 21 days. At harvest fresh weights of shoot and root were determined. These were freeze dried, dry weights recorded, milled and total N and label 15N determined. Various nitrogen use efficiency (NUE) calculations were completed and the results interpreted. For each line shoot:root ratio decreased in the low N regime. Differences in shoot:root ratios and calculated NUE parameters were evident between the selected lines. The implications of using this in breeding nitrogen efficient oat varieties are discussed.