Physiological and biochemical parameters of drought tolerance of some genotypes of garden roses

To identify drought resistance of the studied genotypes of garden roses during the period of maximum probability of drought on the Southern Coast of the Crimea, the water regime, proline concentration, enzyme activity and chlorophyll fluorescence induction parameters under controlled dehydration were studied. Analysis of water regime parameters showed that under conditions of water stress, the best water-holding and recovery capabilities were shown by leaves of cv. ‘Borisfen’ and R. hugonis species. Species R. indica, R. bracteata, R. rouletti, R. foetida showed instability of water regime under conditions imitating dry weather. Studies of changes in biochemical parameters revealed that under relatively mild wilting conditions after removal of stress, metabolic processes are restored in R. hugonis, R. bracteata, R. indica and cv. ‘Borisfen’. Wilting under conditions imitating dry weather does not cause irreversible metabolic disturbances in R. hugonis, R. bracteata, and cv. ‘Borisfen’. Under different wilting conditions, cv. ‘Borisfen’and R. foetida species had relatively stable functioning of FS II. Simulation of dry weather led to irreversible disturbances in the oxygen-releasing complex and thylakoid destruction in R. gallica during the stressor, and in R. indica and R. bracteata species - after recovery of water availability. The highest drought tolerance is in in cv. ‘Borisfen’and R. hugonis sprcies.