Evaluation of chlorophyll fluorescence as a tool for salt stress detection in roses

The induction kinetic of the chlorophyll (Chl) fluorescence and the Fv/Fm ratio have been tested in order to find out the suitability of this technique to evaluate damage caused by salinity in plants of Rosa hybrida cv. Ilseta grafted on R. manetti growing in a greenhouse under non-saturating irradiance. Under these conditions salinity induced changes in plants morphology, nutrient and Chl contents and in the gas exchange parameters, but not in the Fv/Fm ratio. The Rfd index did not reveal more information. The Fv/Fm ratio as well as the fluorescence induction curves were more affected by salinity when an irradiation stress was added, therefore as an indicator of salt stress in roses, Chl fluorescence is of limited use when the plants are grown without additional stress.