Enhancement of Saline Water for Irrigation of Phaseolus vulgaris L. Species in Presence of Molybdenum

摘要

Salinity constitutes a major obstacle in the production and plant growth especially in the Mediterranean region where water quality plays a major role. In the Maghreb more than 30% of water for irrigation is loaded with salt, and it induces the reduction of growth and yield of sensitive varieties. So, research for plants adapted to high levels of salinity becomes an imperative for agricultural production. The bean (Phaseolus vulgaris L. ) is an important source of dietary protein in many developing countries but is considered as sensitive species to salinity compared to other vegetables. Molybdenum (Mo) is a trace element in soil, it is involved in the biosynthesis of several enzymes necessary for growth of most biological organisms, plants and animals. We tried in our work to elucidate the effect of different concentrations of molybdenum (MO: 0, Ml: O.lppm, M2: 0.2ppm and M3: 0,4ppm) by the addition of ammonium molybdate ((NH4) 6Mo7024.4H20) on seedlings of Phaseolus vulgaris Var. Djedida subjected to salt stress by providing five NaCl treatments (TO: 0, Tl: 3g/l, T2: 6g/l, T3: 9g/l and T4: 12g/l) in water of irrigation. To highlight the response of these seedlings we conducted an assay of total chlorophyll (Chi (a+b)) by spectrophotometer, and determination of the morphological parameters such as length and biomass of shoots and roots. The bean plants are able to maintain an optimum level of total chlorophyll and their morphological parameters under the condition of mild salt stress (3g/l) but in the presence of molybdenum, it could alleviate the negative effect of NaCl. We concluded that the presence of molybdenum in concentrations of 0.1 and 0.2ppm in the culture medium of Phaseolus vulgaris irrigated with saline water increased the chlorophyll content and the plant biomass yield.