RÉPONSE ADAPTATIVE DES PLANTS DE Parkinsonia aculeata l

Abstract

Parkinsonia aculeata L. or broom is a leguminous plant of the subfamily of Caesalpinoïdeae, strongly widespread in almost all the tropical and subtropical countries and in the semi-arid and arid areas. In Algeria, its recent introduction successful initially into the parks and gardens, especially in a typical area of stress like Tamanrasset, cause the attention. A first evaluation of the reaction of the species to an osmotic constraint imposed by the PEG6000 shows an answer of the species in relation to the intensity of the stress and its time of application. The first answer relates to the water holding capacity at the foliar level, appreciated thanks to measurements of the relative content water. This holding capacity is observable when the time of application of the imposed stress is 12 midnight for a concentration in PEG6000 not going beyond 20%; for a time of 48 hours application, but for a concentration in PEG6000 not exceeding 15%; or for a time of 72 hours application, but for a concentration in PEG6000 not exceeding 10%. The second answer relates to the accumulation of the observable proline when the concentration in PEG6000 does not exceed 15% for a time of application of the 24 hours stress; do not exceed 10% for a time of 48 hours application; or 5% for a time of 72 hours do not exceed application.