Divergent Selection for Amino-nitrogen Concentration in Sugarbeet Roots

Abstract

Amino-nitrogen is a naturally occurring constituent of sugarbeet that interferes with the extraction of crystallized sucrose during normal factory operations. This study examined 1) the extent amino-nitrogen concentration could be altered by selection within a broad-based germplasm line and 2) the impact selection for amino-nitrogen had on other components of processing quality. Four cycles of mass selection for low amino-nitrogen concentration resulted in a 29% reduction; whereas, selection for high amino-nitrogen concentration increased the concentration by 50%, compared to the parental source. The line selected for low amino-nitrogen concentration had higher concentrations of two other impurity components, sodium and potassium, and a lower sucrose loss to molasses than the line resulting from selection for high amino-nitrogen concentration. Selection for amino-nitrogen concentration, either high or low, did not have a detectable impact on sucrose concentration. Root yield of the line selected for low amino-nitrogen was 9 Mg ha -1 greater than the root yield of the line selected for high concentration.