Raman spectroscopy
The interpretation of Raman spectra was concentrated on carotenes content and allowed to find small differences in accumulation of these substances between investigated genotypes. The band positions and spectral patterns of various components, served as references for Raman spectra of samples and for the calculation of relative intensities (I/mm2 of area), allowed identification of studied substances (Kurdziel et al., 2015 and Wesełucha-Birczynska et al., 2012). The ν band that appeared at ca. 1529 cm−1 was characteristic for double bond C C, present in carotenoid molecules. For the studied leaves, the estimation of the average intensity of this bands indicated that amounts of carotenes were slightly higher in plants grown under drought stress conditions, especially in the Cam/B1 genotype