[Potassium influence on the response of olive tree leaf (Olea europaea L.) to water stress] | Influencia del potasio en la respuesta de la hoja de olivo (Olea europaea L.) al estres hidrico
1997
Melliti, S.
The subject of this thesis deals with the study of the influence of potassium on water exchanges at the level of the leaf of the olive tree (Olea europaea L.). This work was carried out on young plants of the two North African cultivars 'Chemlali Kabylie' and 'Chetoui' descended from propagation by semiligneous cuttings. We noticed that a low concentration of potassium in the leaves of these cultivars leads them to a significant transpiration giving then rise to their dehydration. When water supply is sufficient, the two cultivars exhibit a comparable level of transpiration. On the other hand, under hydric stress conditions, the transpiration of the 'Chemlali Kabylie' is less than that of the 'Chetoui'. This effect is more pronounced when the potassium concentration decreases. In the same treatment, the 'Chelali Kabylie' cultivar exhibits a higher absorption level of the potassium element than the 'Chetoui' cultivar, however the water content is the same. The results suggest that potassium deficiency alters the regulation mechanisms of water exchange in the leaf leading then to a significant transpiration. A possible mechanism explaining leaf dehydration during potassium deficiency could be the alteration of the organisation of the mesophyll of the leaf in this case.
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