Novel evaluation method of flower senescence in Freesia (Freesia hybrida) based on apoptosis as an indicator

Abstract

Flower longevity is an important character for cut flower quality. However it is hard to evaluate flower senescence objectively, and critical measurement method is required. To improve measurement methods of flower senescence, we tried to estimate the wilting process of freesia petals based on apoptotic cell death as an indicator. Apoptotic changes such as chromatin condensation, nuclear fragmentation and DNA fragmentation were observed in the petals undergoing senescence. A good correlation (r=0.84) was also observed between the rate of nuclear fragmentation detected by flow cytometry and the rate of cell death indicated by trypan blue staining in petals. These results suggested that the rate of nuclear fragmentation reflected flower senescence, and that it was possible to evaluate flower senescence using flow cytometry.