NEAR-INFRARED REFLECTANCE ESTIMATES OF GRAIN PROTEIN AND MALT EXTRACT IN HILL AND ROW PLOT EVALUATIONS OF SPRING MALTING BARLEY

Expensive, time-consuming analyses can limit selection responses for grain protein and malt extract in a malting barley improvement program. Alternative breeding strategies, such as doubled haploid recurrent selection, rapidly produce more genotypes than can be evaluated in conventional plots. Prior to implementing a doubled haploid recurrent selection program for malting quality we sought to test the utility of hill plot evaluation and near-infrared reflectance (NIR) prediction for grain protein and malt extract. Five- and six-wavelength calibration equations were generated for prediction of grain protein and malt extract, respectively. The multiple correlation coefficient of the protein equation (0.96) was higher than that of the malt extract equation (0.88). Calibration equations for both traits based on separate locations and spike classes (two-row vs. six-row) were less robust than the multiple environment, combined equations. The grain protein and malt extract equations had acceptable predictive power for both row and hill plot samples. However, in view of differential trait expression in hill and row plots, NIR prediction based on hill plot evaluation is appropriate for grain protein. NIR prediction of malt extract is best deferred until genotypes are evaluated in row plots.Key words: Malting quality, NIR, hill plots, barley