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Cowpea is among the most grain legumes consumed in Algeria. The Algerian Saharan is a hostile environment characterized by high temperatures, scarcity of water and salinity of water and soil. In these regions, the farmers have for generations cultivated landraces cowpeas which are probably adapted to these particular environments and which may have particular nutritional and functional characteristics. These cowpeas deserve to be known and exploited in breeding and improvement programs. This study aims to determine the nutritional value and functional properties of Saharan cowpea through their chemical composition and the analysis of biochemical variability between accessions taking into consideration the environments of origin. Eighteen cowpea landraces were harvested in an arid region of southern Algeria (Hoggar, Tamanrasset). The seeds composition was evaluated by the determination of certain chemical characteristics such as moisture ash, crude protein, fat, total carbohydrates, and energy value. The antioxidant activity was also evaluated which includes total non-enzymatic antioxidant capacity (CANET) and lipid peroxidation, which were determined by conventional methods. The results showed variability among the accessions studied (p ≥ 0.05), and that all the landraces had high crude protein and total carbohydrates. The total non-enzymatic antioxidant capacity (CANET) recorded is low, as well as lipid peroxidation. The moisture content, ash content and fat content were also low in these saharan cowpea accessions. The Functional properties of the flour were also evaluated. The water absorption capacity (WAC) varies with an average of 1.17 g/gMS, the oil absorption capacity (OAC) with an average of 0.4 g/gMs, and the swelling index (SI) with an average of 2.63. The accessions NEA7 and NEA13 are the richest in protein and they have the highest nutritional value. We report here for the first time that cowpea seeds grown in the Hoggar region have high biochemical variability and highly acceptable functional characteristics; however, they could be a good source of nutrients.

Nitrogen fixation resulting from mutual symbiosis of rhizobia and cultivated legume plants is therefore critical to food security as it directly affects agricultural production. Biological Nitrogen Fixation (BNF) can be an important factor in sustainable agriculture. A collection of 20 isolates from fresh Nodules of the legume plant Vicia faba was isolated from five soil of Algeria. The soil from each region has undergone physical-chemical analysis : (granulometry, total carbon, organic matter, pH, and electrical conductivity, determination of available phosphorus and determination of total nitrogen). A media viz., Glucose-Peptone Agar (GPA), Congo red, Yeast Mannitol Agar (YMA) containing 2% NaCl were employed to make presumptive decisions on the recognition and classification of the isolated bacterial strains. All the isolates were found with poor absorption of dye Congo red and little or no growth on the media of GPA and without altering the pH. Almost all of the isolates exhibit good growth on 2% NaCl, poor growth on GPA, thus confirming the rhizobia. After biochemical tests like catalase test and citrate utilization test isolates were confirmed. The presence of rhizobia on root nodules of leguminous plant.

The objective of this study was determination of the taxonomic position of these isolates and the evaluation of the levelof approximation or divergence between these strains and the reference strains belonging to different genus of rhizobia.Amplification of the ribosomal 16S rDNA gene (PCR / RFLP of 16S rDNA) was digested with four different restrictionenzymes: Msp I, Hinf I, Hha I and Taq I. The results of different electrophoretic profiles of fragments obtained shown theselection of the most discriminating enzymes Msp I and Hinf I. The length polymorphism of the restriction fragments(RFLP) analysis of PCR amplified 16S rDNA was compared with those of reference strains. Numerical analysis ofmolecular characteristics showed that 20 strains studied were divided into three distinct groups; we noted that threeisolates only Lablab purpureus have a high level of similarity with the reference strain "Bradyrhizobium", while 17isolates did not exhibit precise taxonomic status and therefore their exact phylogenetic classification is to be determined.The nearly complete sequence of the 16S rRNA gene from a representative strain of each REP-PCR pattern showed thatthe strains were closely related to the members of the family Bradyrhizobium.