• Mitotic indices of rice and bean seed roots decreased after accelerated aging. • Chromosomal alterations and DNA breaks increased in artificially aged seeds of rice and bean. • The potential for use of the comet assay in seed conservation programs is shown. Loss of genetic integrity can occur during the long-term conservation of seeds. We have studied these effects in seeds of rice (Oryza sativa L.) and common bean (Phaseolus vulgaris L.) exposed to accelerated aging (elevated temperature and moisture) conditions. Tests of first count, germination, and germination speed index were performed to measure physiological quality; cytogenetic tests and comet assay were used to evaluate genetic integrity. With aging, we observed a decrease in mitotic index and an increase in the frequency of chromosomal alterations in root cells of imbibed seeds, as well as increased DNA damage (comet assay) in dry and imbibed seed embryos of both species. The comet assay can be a useful technique for measuring genetic integrity in seed conservation programs. [ABSTRACT FROM AUTHOR]