Genotype × Environment Interaction for Grain Color in Hard White Spring Wheat

Abstract

Improvement of grain color in hard white spring wheat (Triticum aestivum L.) breeding programs depends on understanding the influences of genotype (G), environment (E), and their interaction (G × E). The objectives of this study were to quantify genetic variability for grain color and assess the nature of the G × E interaction in determining grain color in 79 spring wheat genotypes. Twelve check cultivars [seven hard red (HR), four hard white (HW), and one soft white (SW)] and 67 white‐seeded Australian (AUS) accessions were grown at two locations across 2 yr. Wheat genotypes differed significantly in agronomic traits, grain protein, and kernel hardness. Grain and meal color were quantified using Hunterlab colorimeter values. Whole grain color values without (L = 40.9–50.4 units; a = 7.0–8.3; b = 13.6–19.1) and with NaOH treatment (L = 22.7–38.1; a = 7.7–9.7; b = 9.2–17.9) varied among genotypes. Using ground meal, color values (L = 80.1–84.9; a = 1.8–2.6; b = 8.9–11.8), yellow pigment content (2.5–4.8 μg g−1), and lutein content (1.8–3.7 μg g−1) varied among genotypes. Genotype × location (L) interactions were not significant for colorimetric and pigmentation variables. The Azallini and Cox test detected one crossover G × year (Y) interaction for grain a‐value (without NaOH), one for grain b‐value (without NaOH), and 12 for lutein content. Genetic variation exists for grain color among HW genotypes. The noncrossover nature of G × E interactions for grain color indicates that white‐seeded genotypes selected as superior in one environment will be superior in other environments.