Variabilité des caractères morphologiques et composition minérale des populations naturelles d’Atriplex halimus Cas Mostaganem et Oran

Abstract

The results obtained in this work have allowed us to say that the Atriplex halimus is a polymorphic plant, this morphological polymorphism seems to be a characteristic that manifests itself in the size and shape of leaves, fruiting valves. A variability in the height of the clumps as well as the diameter according to the seasons and since the season of the spring is a season of the development and growth of the plants it has been noticed that during this season the height is of 230 cm and the diameter is of 23.10 m for the two sites studied. For the Oran site the clumps are far from being exposed to overgrazing so we observe less degradation they form a thick thicket, the clumps of the site Mostaganem which is located on the cliffs are exposed to the wind and sea spray their morphology is low and less developed in length and diameter in the shape of a cushion. The leaf ratio indicates that the leaf shape of both sites is characterized by good development during the spring season and the winter season where records are recorded between 0.58 and 0.68, so the leaves are longer than broad typical lanceolate of the Atriplex halimus. A clear difference between the fruiting valves of the Mostaganem site and the Oran site with regard to the ratio (width/length) 0.717 for the Mostaganem site and 0.496 for the Oran site the fruiting valves of the Oran site are small and less developed. The study of the chemical composition (MS, MO, MM, CB and proteins) of the consumable phytomass in its global form. The results obtained allowed us to identify the shrubs used nutritionally, in fact, the Atriplex halimus has levels of MO, MM, CB and CB and proteins which are respectively high. He results of the percentages of dry matter, clearly show an increase of this parameter, spring season for leaves. The stems, the roots and the fruiting valves are recorded at 46.6, 56.9 and 63.8 during the fall season. For the Mostaganem site, it is the autumn season that is rich in dry matter production for all the organs analyzed. The mineral contents clearly show that the winter season is richer for the organs stems leaves and fruiting valves 29.8, 30.8 and 28% for the root is the spring season 27%, for the site Mostaganem marks a variability between the organs analyzed leaf and fruiting valves mark a high rate during the autumn spring season, for the stem it is winter with a rate of 28% and the root is the spring (27%) Oran site. For the Mostaganem site it is the stems, roots and fruiting valves that are richer in crude fiber with 29, 48 and 32 %. The site Oran is the leaves that are rich in crude cellulose12 %. The organic matter content is higher in autumn in the leaves against the analysis of stems, roots and fruiting valves is winter and spring for the site Mostaganem. On the other hand, the Oran site is the fruiting stems, roots and valves that have a very high content during the fall season; the leaves are the winter that is richer. The protein content is the Oran site which is the richest protein regardless of the organ analyzes leaf 268 mg/g, stems 172 mg/g, roots 316 mg/g and fruiting valves 178 mg/g. The Morphological study shows a very great physiognomy and heterogeneity of the formations of the natural populations of Atriplex and their nutritive values allows their use as a forage plant.