Effect of Water Stress on Apple Rootstock MM.106

This study was undertaken to identify the morphological and physiological changes compared to the control in the rootstock MM106 of apple tree Malus domestica Borkh, under the effect of 4 levels of water stress (100% Hcc (Control), 80, 60 and 50% Hcc). The effect of water stress caused a significant reduction in plant growth parameters such as fresh and dry weights of different organs (Roots, Stems and Leaves) under different levels including number of leaves, sympodial growth and relative water content in all plants. Generally, the effect of watering level of 80% Hcc frequency was found to be insignificant. However, a highly significant impact was observed in the different parameters measured in the 60 and 50% Hcc submissives compared to the control. In spite of these results, the MM.106 rootstocks, even under severe stress, did not show any wilting or dieback phenomenon after 60 days of application. Key words: Rootstock MM106, Malus domestica Borkh, water stress, tolerance, morpho-physiological parameters.