Roots are hidden by soil, making their excavation and measurement of their size very laborious (Gregory, 2006) and difficult to analyze (Rood et al., 2011). However, the study of their spatial distributions allows the discovery of their main sources of water and minerals (Lynch, 1995). Given the quantitative and qualitative heterogeneity in Abstract: Despite xeric conditions, Pistacia atlantica Desf. subsp. atlantica (Atlas pistachio) succeeds in developing impressive dendrometric dimensions (25-m high, 2-m trunk diameter). It is among the rare spontaneous phanerophytes of the North African steppe. With access to water being the primary condition for survival, we focused on its root system. According to a gradient of increasing climatic and edaphic aridity in Algeria, we recorded different root architectures set up by this tree. We sampled its underlying soil and determined its main physico-chemical characteristics. Root architecture is mainly of the superficial type with more than 60% of roots located in the top 50 cm of soil along the north-south transect. With the decrease in precipitation and the rising of temperatures, length of the dry season, and the content of sand in soil, the number of superficial roots and their ramifications decrease, while their average circumferences, and the length and average circumference of the deep roots increase. These deep and thick roots allow access and storage of moisture present in the deep levels and protected there from evaporation, and, on the other hand, provide an important anchor in these soft soils. The Atlas pistachio adapts to increasing climatic and edaphic aridity by adopting a phreatophytic strategy.

Nettle (Urtica dioica L), as a plant rich in biologically active compounds, is one of the most important plants used in herbal medicine. Studies have shown that this plant has antioxidant, antiplatelet, hypoglycemic and hypocholesterolemia effects. In this study, we characterized three Alternaria endophytic fungi isolated from their host U. dioica. We hypothesized that these endophytic fungi can produce new bioactive metabolites, which may possess the bioactive property with potential application in the medical and pharmaceutical industries. The antibacterial activity was evaluated against reference and isolated strains, including Methicillin-Resistant Staphylococcus aureus. A wide range of antimicrobial activities similar to those measured in nettle leaves was detected especially for Alternaria sorghi. Furthermore, the highest antioxidant activity detected with DPPH free radical scavenging was measured for A. sorghi and nettle leaves ethyl acetate extracts. In addition, whereas catalase activity was similar in the three isolated fungi and nettle leaves, total thiol content and superoxide dismutase activity were significantly higher in leaves. A. sorghi showed the best activities compared to other isolated fungi. The characterization and further production of bioactive compounds produced by this endophyte should be investigated to fight bacteria and especially those that develop drug multi-resistance.

Short term changes that occur in soil properties of an ultisol under different pigeon pea hedgerow alley populations and inter-hedgerow alley spacing and the effect of such changes on ginger rhizome yield response were evaluated in a two-year (2010 and 2011) field study in South Eastern Nigeria. Treatments comprised pigeon pea hedgerow alley populations of 20,000, 33, 333 and 66, 667 plants/ha in factorial combinations with three inter-hedgerow alley width spacing of 1, 2 and 3 m in a randomized complete block design with three replications. A plot having no pigeon pea component but planted to sole ginger constituted the control. Relative to the control, growing ginger in-between pigeon pea hedgerow alleys resulted in significant improvement in soil exchangeable Ca, Mg, and K, base saturation, organic carbon and available P in addition to reducing soil dry bulk density. Highest response in soil available P, organic carbon, dry bulk density, exchangeable Ca and Na and pH was achieved using pigeon pea population of 66, 667 plants/ha, while highest response for soil total N, base saturation and exchangeable K was achieved with 20,000 pigeon pea plants/ha. Optimum ginger rhizome yield response comparable with the control was achieved using pigeon pea hedgerow alley population of 20,000 plants/ha spaced 3 m apart. Increasing pigeon pea hedgerow alley population beyond 20,000 plants/ha and decreasing pigeon pea inter-hedgerow alley width below 3 m resulted in rhizome yield reduction due to probable nutrient competition. Apart from its capacity to continuously maintain the fertility of the fragile and infertile soils of South Eastern Nigeria, planting ginger in-between pigeon pea hedgerow alley will also serve as additional source of revenue to smallholder resource-poor ginger farmers in Nigeria.

Endophytic fungi that reside in plant tissues are a potential source of secondary metabolites with biological activities. In our study, we investigated the detection of the antioxidant activity of the crude fungal extract of the genera Cladosporium, Alternaria, Aspergillus and Penicillium: endophytic fungi isolated from the leaves of Peganum harmala harvested in Laghouat and extract of these same leaves. The extraction of these metabolites was carried out using ethyl acetate. The antioxidant activity of the latter was carried out by the DPPH test.Our tests reveal that the extracts studied have a low antioxidant activity. The inhibitory concentrations show a higher antioxidant effect for the Penicillium extract compared to the other extracts studied. The antioxidant molecules are related to the content of polyphenols.Penicillium extract has the highest polyphenol content. Our results confirm that endophytic fungi are a potential and limited source of natural antioxidant compounds, in the same way as plants.

This study was carried out on two types of Camembert produced in the region of Tizi-Ouzou (northern Algeria), one artisanal (AC) made from raw milk and the other industrial (IC) made from pasteurized milk. This work shows the effect of milk quality and cheese making processes on the progress of physicochemical and microbiological parameters throughout a maturation period of 12 days. The result shows that the repining microflora and undesirable microbial populations were significantly higher (P < 0.05) in the artisanal Camembert (AC) than in the industrial Camembert (IC). The physicochemical and microbiological parameters, during the ripening of the cheeses developed in a similar way with significant differences according to the type and the stage of maturation. During the cheese repining period, AC showed more extensive (P < 0.05) lipolysis and proteolysis than IC. SDS-PAGE of water-soluble proteins (WSP) and insoluble fractions showed more extensive degradation of s-casein (s-CN) than β-casein (β-CN). The WSP profile, analyzed by Reversed-Phase High Performance Liquid Chromatography (RP-HPLC), was highest in AC than IC. The highest WSP profile was recorded at the 12th day of repining. The pathogenic flora decreased during the maturation process in AC. This development was confirmed by the results of the antibacterial effect of WSP, performed by the disc diffusion technique on Escherichia coli and Staphylococcus aureus strains. From this study, it can be concluded that AC has a better organoleptic quality, safe for the Algerian consumer and more profitable for the Algerian cheesemakers