Kernel color variability of hard white and hard red winter wheat

The introduction of hard white winter (HWW) wheat into the traditionally hard red winter (HRW) wheat (Triticum aestivum L.) production area of the Great Plains requires discrimination between the two classes if they are to be bred and marketed concurrently. Visual discrimination would be an advantage to a HWW selection program where segregation for kernel color is expected. This study was conducted to quantify genetic variability and genotype x environment (GE) interaction for kernel color. Twenty-four HWW winter wheat experimental lines, three HWW cultivars, and five HRW cultivars mere grown in a randomized complete block design in one greenhouse and eight held environments during 2 yr. The harvested grain of each plot was visually rated by a color-rating scale having equidistant values of 1 (lightest) to 10 (darkest), Average color rating ranged from 1.6 to 5.8 across genotypes and from 2.0 to 3.8 across environments. Though the majority of HWW genotypes had a mean rating of less than or equal to 3, variation among single ratings of red and white genotypes was nondiscrete, Variation in kernel color was partly attributed to GE interaction, but genetic differences in color expression and stability were found among HWW genotypes, The HRW cultivar, Custer, and two HWW lines demonstrated exceptional stability based on regression and rank statistics. Genotypic differences in kernel color were not associated with differences in kernel hardness or date of physiological maturity. The presence of genetic variation for kernel color should favor selection for lighter and more consistent bran color.