Complementing breeding effort by deploying alternative methods of identifying higher yielding genotypes in a plant breeding program is important for obtaining greater genetic gains. Spectral reflectance indices (SRI) are one of the several indirect selection tools that have been reported to be associated with many physiological processes of different crop species. The value of SRI as a plant breeding tool for yield improvement has not been well established. Therefore, this book provides a comprehensive analysis of the potential use of SRI as a plant breeding tool for yield improvement using breeding populations and released cultivars of wheat. Association between grain yield and SRI, biomass and SRI, heritability of the SRI and yield, response to selection and correlated response, relative selection efficiency of the SRI, and efficiency in selecting the higher yielding genotypes by the SRI are discussed. The findings should help wheat breeders to utilize SRI as an indirect selection tool for yield improvement.