Predicting the Number of Dominant R Alleles in Single Wheat Kernels Using Visible and Near-Infrared Reflectance Spectra

ABSTRACT An optical radiation measurement system was used to measure reflectance spectra of single wheat kernels from 400 to 2,000 nm. A total of 18 wheat samples with 0, 1, 2, or 3 R alleles for red grain color was used for this study. The results indicated a linear relationship between the degree of the red pigmentation and the number of R alleles. The highest coefficient of determination (R2) was 0.78 in the wavelength region of 500–1,700 nm when a four-class partial least squares model was used. The highest classification of red genes was 78.4%. For two-class models, differentiating samples with 0 R alleles and 1 R allele from samples with 3 R alleles had the highest success rate of 100 and 98.8%, respectively. The number and combination of R alleles had a significant effect on wheat kernel color. These relationships may be useful to wheat breeders in estimating the number and location of R alleles.