Ecophysiological and species-specific responses to seasonal variations in halophytic species of the chenopodiaceae in a Mediterranean salt marsh

摘要

Plants adopt different strategies in response to seasonal variations in their natural biotype. In this study, the responses of seasonal changes on the organic osmolyte contents, ionic homoeostasis, osmotic potential and succulence of native chenopods in a salt marsh of Egypt were studied. Five halophytic species of the chenopodiaceae were collected during the rainy and dry season: Atriplex halimus L., Halocnemum strobilaceum (Pall.), Salicornia fruticosa (L.), Suaeda pruinosa (Lange) and Arthrocnemum macrostachyum (Moric). Results showed that plants employ an osmoconformer strategy via species specificity of response to seasonal variations. The total ions accumulation in all species was higher during the rainy season compared with the dry season. In particular, during rainy season, A. halimus resulted the higher accumulator species, followed by H. strobilaceum. Conversely, S. fruticosa, S. pruinosa and A. macrostachyum were defined as low-accumulator species. In each studied species, the effective salinity, biological absorption coefficient as well as leaf succulence were higher during the rainy season. In conclusion, the present study have pointed out the importance that should be accorded with the development of research directed towards agronomic aspects for the uses of halophytic chenopodiaceae in salt marsh. Further, data obtained indicate that the ions accumulator species should be considered for use in phytoremediation of degraded saline lands.