Mean number of chromocenters in the interphase nuclei was studied in 2 inbred lines of radish (R. sativus L. var. radicola Persoon), their F1 hybrid and the original population. The inbred lines showed a significantly higher mean of chromocenters in the interphase nuclei than the original population, suggesting more heterochromatinization in the former. Mean number of chromocenters in the nuclei is restored in the plants of F1 interlinear hybrid. A genotypic control of chromocenters was proposed in radish.