The study of physiological senescence of the flag leaf playing the pivotal role in the uptake of solar energy and stipulating plant productivity in wheat is very important for providing high productivity under stress. Therefore, using RAPD OPH13 marker, the existence of a gene-locus linked to the physiological flag leaf senescence was examined in wheat genotypes under drought stress. Based on the analysis of PCR profiles, 450 bp diagnostic fragments were identified in 31 bread wheat and in 15 durum wheat genotypes. This result shows that there is a gene locus that provides physiological rejuvenation of the flag leaf, which is an indicator of the resistance to drought stress in those genotypes. The existence of the studied locus was not confirmed in 19% of the genotypes.