Salt stress effects on enzymes activities involved in carbon metabolism and nitrogen availability of two Tunisian durum wheat varieties

Two varieties of durum wheat (Om Rabiaa and Karim), were analyzed and evaluated in the presence of increasing doses of NaCl (0, 100, 200 and 300?mM) in which we added different concentrations of nitrate (0.1, 3, 10?mM). The data obtained showed that presence of NaCl in the culture medium induces the increase of the salt accumulation levels (Na⁺, Cl^?) and reduces the levels of K⁺ and NO₃^? in the cultivar Om Rabiaa. In Karim variety, ions that have been heavily accumulated following exposure to NaCl are Na⁺ and K⁺ while low levels of NO₃^? and Cl^? have been detected. Those findings highlight the difference in the salinity tolerance of durum wheat cultivars also depending on nitrogen (N) availability, Karim cultivar being less sensitive to NaCl treatment than Om Rabiaa. These data also suggested a relationship between salt tolerance capacity and enhancement of nitrogen and carbon metabolisms enzyme activity.     

Evaluation of Tunisian milk quality in dairy herds: Inter‐relationship between chemical,physical and hygienic criteria

The objective of this paper was to evaluate the global milk quality in Tunisian dairy herds. Samples of milk were analyzed for chemical, physical and hygienic parameters. Milk total solids, fat content and density were consistently correlated and one of them can be used as a chemical indicator of milk quality. The somatic cell count value of 689 × 10³/mL was higher than the recommended threshold. All milk samples were positive for the major pathogen Staphylococcus aureus. These hygienic parameters were related more closely with chloride content, minerals and electrical conductivity, which allows them to be used as indicators of mammary gland infection. It was concluded that milk producers have at hand rapid and easy tools for assessing the overall quality of milk.