Effect of Nitrogen Source on Grain Development in Detached Wheat Heads in Liquid Culture

Abstract

Detached wheat heads (8 days post anthesis) were grown in liquid culture using media containing various nitrogen sources at different concentrations. Grain development in terms of dry weight, nitrogen, starch and protein were equivalent whether the nitrogen was supplied as either a complete spectrum of amino acids or as glutamine, asparagine or ammonium nitrate. Where the concentration of nitrogen in the culture medium was varied while maintaining the sucrose concentration constant, no variations were observed in the rate of grain dry weight or starch accumulation. Nitrogen per grain and percentage grain nitrogen increased with increasing concentrations of nitrogen in the culture medium. Percentage grain nitrogen was higher in the 'high protein' cultivar Timgalen than in the 'low protein' cultivar WW 15 at equivalent nitrogen concentrations in the culture medium, but differences in percentage proteins were only small.