Analysis of the Breeding Utilization Effects of Loci Related to Wheat Flour Color

The flour color is a crucial index for evaluating wheat quality. Identifying superior allelic variations at loci associated with flour color and clarifying their breeding utilization effects will provide a foundation for molecular marker-assisted breeding of wheat flour color.

Using functional markers, molecular detection was conducted on 12 flour color-related loci in 166 wheat varieties (lines), including the Psy-A1, Pds-B1, Lcye-A1, Lcye-B1, Lox-B1, Ppo-A1, Ppo-B1, Ppo-D1, Pod-A1, Pod-D1, Pod-2D genes, and the 1B/1R translocation. Combined with the phenotypic measurements of flour color parameters (Yellow pigment content (YPC), L^* value, a^* value, b^* value and whiteness), the influence of different allelic variations on flour color were analyzed to comprehensively and systematically evaluate the breeding utilization effects of each locus.

The flour color of the tested materials exhibited a wide variation range. The average value of YPC was 1.18 μg·g^-1, with a range of 0.57-2.96 μg·g^-1; The average value of L^* was 90.29, ranging from 87.12 to 92.16; the average a^* value was-0.86, varying between-1.78 and-0.09; the average b^* value was 8.83, with a range of 5.21-14.69; and the average whiteness was 86.78, spanning from 81.35 to 90.30. Environment, genotype, and the interaction between genotype and environment all significantly influenced flour color, with genotype exerting the strongest effect on the phenotypic variations. Psy-A1 and 1B/1R translocation significantly affected YPC, L^* value, a^* value, b^* value and whiteness; Lcye-B1 significantly influenced YPC, a^* value, b^* value and whiteness; Pds-B1 and Lox-B1 significantly impacted L^* value, b^* value and whiteness; Pod-2D significantly influenced L^* value and whiteness; Lcye-A1 significantly affected L^* value; Ppo-A1 and Ppo-D1 significantly influenced a^* value. These nine loci had substantial impacts on flour color and exhibited great potential for breeding applications. Wheat varieties (lines) containing Psy-A1b, Pds-B1b, Lcye-A1b, Lcye-B1b, Lox-B1a, Ppo-A1b, Ppo-D1a, Pod-2D-GG, Pod-2D-AG and non-1B/1R translocation exhibited high brightness and whiteness flour color. These genotypes were designated as superior alleles, with distribution frequencies of 34.94%, 20.48%, 97.59%, 66.27%, 26.38%, 50.91%, 57.23%, 48.80%, 15.06% and 51.20%, respectively. As the number of superior alleles increased, the L^* value, a^* value and whiteness gradually increased, while YPC and b^* value gradually decreased. The materials pyramiding 7-8 superior genes exhibited the optimal flour color. There were significant differences in flour color and the allelic variation frequencies of related genes among wheat varieties (lines) from different regions. A total of 22 varieties, such as Zhengyin1, Zimai12 and Wanmai19, carried more than seven superior alleles and could be used as parental materials for breeding wheat varieties with high brightness and whiteness flour.

Psy-A1, Pds-B1, Lcye-A1, Lcye-B1, Lox-B1, Ppo-A1, Ppo-D1, Pod-2D and 1B/1R translocation significantly influence flour color and exhibit strong breeding practicability. Twenty-two wheat varieties, such as Zhengyin1, Zimai12 and Wanmai19, can be used as excellent parents for flour color improvement.