The relation between nitrate reductase activity and grain nitrogen productivity in wheat

Abstract

The seasonal patterns of leaf nitrate reductase activity were compared in five wheat cultivars which differ widely in their capacities to accumulate grain nitrogen. Significant differences in the average levels of nitrate reductase activity were observed between cultivars. Total seasonal nitrate reductase activity was closely related to total plant nitrogen at maturity. Grain nitrogen was only related to total seasonal nitrate reductase activity when allowance was made for significant differences between cultivars in nitrogen redistribution patterns. The significance of these results with respect to the possible use of nitrate reductase activity levels as a selection criterion for nitrogen productivity is discussed.