Five quinoa cultivars introduced from Egypte DRC (Desert Research Center-Caire) were tested in an experimental station in Tunisia located under arid climatic conditions. In order to test their adaptation to abiotic constraints; water requirements, yield (grain, dry matter) and water use efficiency (WUE) were correlated to three water stress: T100% of field capacity (T1), T60% of field capacity (T2) and T30% of field capacity (T3). Net irrigation water requirement was estimated using CROPWAT 8.0 software. The study aims to develop an irrigation scheduling for quinoa from January to Jun during 2015 season. The ET0 was between 1.08 mm/day and 4.95 mm/day and net irrigation water requirement was 287.2 mm. For grain yield, 1000 grains weight and dry matter production results show significant differences between cultivars and water stress. The seeds productivity of the five cultivars ranges between 2092.6kg/ha and 270kg/ha under full irrigation and it decreases to reach up 74% under T3 of field capacity stress in comparison with control stress. Similar results were shown for dry matter production. On refilling soil to field capacity with irrigation at critical depletion, 70% field efficiency was achieved which correspond to optimal condition, while adapting fixed interval per stage. For WUE, highest value of irrigation and total water use efficiency for both grain and dry matter  ​​were recorded to the T2 hydrous stress.

Pea (Pisum sativum L.) is an important legume for human and animal consumption, cultivated in many temperate regions of the world. In the present investigation, the seeds of twelve pea accessions collected from the arid regions of southern Tunisia, characterized by different colors of flowers and seed coats, were evaluated for their proteins, phenolic compounds and antioxidant activities. The protein content determined by the Bradford method ranged from 46.91 to 151.08 mg/g DW. The content of total phenol, total flavonoid and condensed tannin, ranging from 36.85 to 102.52 mg GAE/100 g DW, 6.95 to 48.11 mg QE/100 g DW, and 12.37 to 70.43 mg CE/100 g DW, respectively. These parameters were characterized respectively by the following three methods, the Folin‐Ciocalteu reagent, the aluminum chloride and the vanillin assay. The LC‐ESI/MS analysis identified the presence of 8 phenolic acids and 9 flavonoids which quinic acid, protocatechuic acid, hyperoside, and quercetin‐3‐O‐rhamnosidewere detected as the most abundant compounds. Moreover, the antioxidant activity of pea seeds was evaluated by the ABTS+and DPPH tests. Indeed, DPPH and ABTS anti‐free radical activity values ranged from 1.92 to 14.11 μmoL TEAC/g DW and 2.3 to 14.95 μmoL TEAC/g DW, respectively. The variability across the assessed traits revealed significant differences as computed by ANOVA tests. Else, the results showed significant correlations between seed coat color, seed shape, flower color and phenolic compounds. Therefore, genotypes characterized by a purple flower, brown seed coat, and wrinkled form had the highest levels of phenolic compounds and antioxidant activity. Correlation analysis revealed that phenolic compounds presented a strong positive correlation with antioxidant activities, while being negatively correlated with protein content. UPGMA cluster and Principal component analysis (PCA) revealed two main groups. This work highlights the nutritional value of P. sativum seeds as a good source of natural antioxidant compounds that may be useful in the food and pharmaceutical industries.