Cell membrane stability and water relations of different scions grafted onto Mexican lime under water stress conditions and recovery

The purpose of this study was to evaluate the cell membrane stability and the tolerance of Washington Novell (WN) and Kino Mandarin (KM) grafted onto Mexican Lime (ML) under water stress condition and recovery. A factorial experiment was conducted in the completely randomized design with 4 replications in a plastic greenhouse. Two-years-old graft combinations of WN/ML, KM/ML, ML/ML and un-grafted ML were used as plant materials. The results showed that in water stress condition, KM/ML indicated the same level of cell membrane stability, malondialdehyde (MDA) and total chlorophyll as its control. However, WN/ML exhibited the highest amount of electrolyte leakage and MDA and lowest level of chlorophyll. KM/ML was able to regulate its osmotic potential with accumulating of proline and soluble carbohydrate both in the leaf and in the root and maintains the relative water content. In contrast, the rate of leaf proline and soluble carbohydrate of WN/ML decreased significantly compared to its control. It seems that in WN/ML the reduction of chlorophyll content in drought stress condition can be related to the structural oxidative damage of chloroplasts and the degradation of the pigments. So, ML can be recommended as a suitable rootstock for KM.