Photosynthetic Changes of "prunus Avium L." Grafted on Different Rootstocks in Relation to Mineral Deficiencies

The performance of three different rootstock (Adara (Prunus cerasifera L.), SL 64 (Prunus mahaleb), and Colt (Prunus avium x Prunus pseudocerasus)) as nutrient suppliers has been studied for sweet cherry cultivars (Prunus avium L.). The results obtained suggested that, depending on the rootstock, the trees are submitted to different degrees of stress. According to the data obtained, it could be expected a different photosynthetic pattern of these trees for the same sweet cherry cultivar. Fluorescence measurements as well as photosynthetic pigment composition has been assessed to know the photosynthetic capacity of the trees. The highest Fv/Fm ratio was found in leaves from trees grafted over the rootstock Adara. An increase of the zeaxanthin (Z) content could be observed in the less adequate rootstock variety. Key Index words : Fluorescence measurements, Prunus avium L., VAZ cycle,