Variabilités phénotypique de deux populations naturelles d'Atriplex halimus subsp halimus cas Mostaganem et subsp schweifurthii cas Oran.

Abstract

The present study provides information that can help to determine the phenotypic variability of the Atriplex halimus species in two different climatic contexts. The species were analyzed using leaf characteristics (leaf area and ratio, mean leaf width) the morphology of the tufts and a study of karyotypes. The study showed significant phenotypic variability, which is all the more important as populations are geographically distant and located in different climates. Our results show that the tufts of the sub-species Atriplex halimus subsp halimus site Kharrouba form a very thick bush with a very dense network of erect branch and a branch that spreads from the base, well spread rounded (form of pads), the Height of the tufts is between 118 and 165 cm the diameter is greater than 1000 cm. The shape of the leaves varies from Ob ovoid, oval, lanceolate, Rhomboidal, ... with the lanceolate form typical of subsp halimus. For the site of Es-Senia Oran the Atriplex halimus subsp schweifurthii has a height of tufts which varies between 110 to 240 cm, the diameter is 20 m. The shape of the tufts is spread very well and very branched. The shape of the leaves ranging from oval, rhomboidal, lanceolate, elliptical. Observations of the somatic mitoses enabled us to distinguish well the halimus variety with a diploid chromosomal number of 2N = 18 which was counted for the Kharrouba site. The subspecies halimus is diploid, while the schweinfurthii subspecies harvested from the ES-Senia site (Oran) is tetraploid with 2n = 4x = 36. This phenotypic variability of the natural populations of the Atriplex halimus offers the possibility of selecting a plant material suitable for different regions.