Ecophysiological study of some coastal dune species of Zemmouri El Bahri (Algeria)

Species of coastal dunes are subjected to several environmental stress factors such as drought, high temperature, light intensity as well as salinity, which led to development of specific morphological, physiological and biochemical adaptation mechanisms. Studying these strategies allows explaining the survival of these species in such hostile and stressful conditions. In this study we compared some parameters (morphological, physiological and biochemical) of two Brassicaceae species Matthiola tricuspidata (L.) W.T.Aiton, Cakile maritima Scop., and two Fabaceae species Lotus creticus L. and Ononis variegata L., harvested from their natural environment in coastal dunes of Zemmouri El Bahri (Algeria), with the aim to understand their mechanisms of adaptation. The results revealed that C. maritime showed the highest relative water content, leaf area, leaf mass area, and succulence index. Based on the highest levels of total phenols, flavonoids and anthocyanins as well as high contents of photosynthetic pigments, M. tricuspidata can be classified as "homoiochlorophyllous" plant. The dry mass content varied considerably among species, with the highest values observed in L. creticus and the lowest in C. maritima. As both Fabaceae species L. creticus and O. variegata showed high chlorophylls, carotenoids, total phenols and flavonoids could also be classified as "homoiochlorophyllous" species. The relatively high levels of total phenols, total flavonoids, anthocyanins and carotenoids implies a biochemical adaptation that allows these plants to maintain necessary photosynthetic activity under a water deficiency condition.