Résumé:
Soil salinization is a major limiting factor in agricultural productivity, especially in
arid and semi-arid region. The presence of soluble salts at high concentrations in the soil,
affect physiological mechanisms of the plant and is a major limiting factor of the vegetable
production. Thus, tolerance of cultivated plant is remained, given the complexity of the
mechanisms involved in tolerance to salt plants.
The objective of our work is to study the influence of some bentonite doses associated
with abiotic stresses of salinity on water, biochemical and mineral behavior, of leguminous
species very sensitive to salinity commonly grown in Algeria ; the bean “Phaseolus vulgaris L”.
The tests were carried out in pots of vegetation in semi-controlled conditions in the
greenhouse. Mostaganem bentonite is added at 00, 07 and 10% by weight of the substrate
(sand / peat).The mixture thus obtained is used for culturing a variety of bean Phaseolus
vulgaris , called El Djadida subjected to salt stress using NaC1 solution with 03
concentrations (0, 50 and 100 meq/l). Interest in physiological and mineralogical
characteristics us in adaptation environmental constraints required study of water balance, the
accumulation of chlorophyll pigments and proline and the effect on the absorption of some
cations: Na + , K + and Ca2 + for mineralogical approach.
Salinity effects are manifested by a decrease in water content and chlorophyll
pigments. However, we observed an increase in proline content and the disturbance in the
distributing of Na+, K + and Ca2+ ions in the leaves and roots (The Na+ content increasing
inhibits the absorption of Ca2 + and K+ ions) .These effects is depending to the intensity of the
stress.
The addition of bentonite in the substrates cultures and in the absence of salt
treatment improve significantly the plant growth parameters. It is observed that the doses of
07% for bentonite applied and combined to the salt concentrations are most appropriate that
contribute to the osmotic adjustment and provide a balanced mineral nutrition of the three
cations in the leaves and roots of the bean and improve the other physiological parameters
such as water content and the photosynthesis process.
