INFLUENCE OF NACL SALINITY ON THE BEHAVIOUR OF SUGARCANE CULTIVARS

This work focused on the evaluation and identification of tolerant varieties of sugarcane against salt stress. In this regard, we are comparing the accumulation of ions and defining the (exclusion/inclusion) role of sodium or chloride. For this purpose, the cuttings of five sugarcane varieties were irrigated, with different concentrations of NaCl. The evaluated measurements are the dry biomass, the content in mineral elements Na+, Cl-, K+, and Na+/K+ ratio, in both leaves and roots. The results showed that salinity, has a depressive effect on dry biomass production, in the five varieties tested, and the effect varies with the intensity of stress. In terms of nutrition, the salinity significantly increased the level of chlorides and sodium in the genotypes tested, thus reduced the K+ content. Consequently, the presence of Na+ prevents the absorption of K+, hence the decrease in the K+/Na+ ratio. However, the ratio Na+ leaf/root and Cl- at the leaf/root levels, shows that the sodium content at the root level exceeds the one at leaf level. The results also indicate a varietal difference in salt stress response; was revealed between the varieties studied. Concerning the effect of the variety, three CP varieties are the least affected by salinity, indicating their tolerance. Finally, it may be confirmed from this study, that the adaptation ability to salinity is correlated with the genotype, and that it is related to ion transport properties and the ability to regulate and ionic compartmentalization.