Date palm (Phoenix dactylifera L.) trees are largely cultivated across the Algerian oases; they are principal sources of remuneration and the economic basis for residents of these areas. Date palm fruits are rich sources of essential nutrients, vitamins, minerals, and dietary fibers, with many potential health benefits, yet there are few studies on the chemical composition and biological properties of date palm seed oil. In this study, we present an in-depth characterization of the biochemical composition and antioxidant properties of date palm seed oil (DPSO) produced in Algeria. DPSOs of eight Algerian cultivars, Arechti, Degla-Baida, Deglet-Nour, Ghars, Haloua, Itima, Mech-Degla, and Tentbouchet, were investigated to determine their biochemical compositions and antioxidant properties. The results highlight the potential of DPSO as an alternative food and a natural resource, thanks to several important compounds having high antioxidant capacity. In particular, fatty acids and triacylglycerol (TAGs) analyses showed that oleic (42.74–50.19%), lauric (18.40–22.2%), and myristic (8.83–10.17%) were the major fatty acids, while 1-myristoyl 2-oleoyl 3-linoleoyl glycerol, 1-linolenoyl 2-oleoyl 3-linoleoyl glycerol, 1-2-linolenoyl 3-linoleoyl glycerol, and 1-linolenoyl 2-myristoyl 3-linoleoyl glycerol were the major TAGs. Biophenols and tocopherols analyses revealed the presence of important compounds, such as catechin (22.04–24.92 mg/kg), vanillin (10.67–23.98 mg/kg), and α-tocopherol (443.59 mg/kg), at high remarkable levels. Therefore, a comparison with the literature data concerning other seed oils, including olive oil, confirms that DPSO can be considered a high-quality oil, from a biochemical and biological point of view.

Seed germination is generally the critical step in seed establishment and thus the determination of successful crop production. This study was focused at examination of the biochemical and germination parameters effected by low water potential which was generated by polyethylene glycol (PEG) 6000 and mannitol, related to drought stress and growth of Waha durum wheat genotype. Two tests were carried out in a growth chamber; the first comprises seed germination into Petri dishes in the presence of different concentrations of the two osmoticums (0, 5, 10, 15 and 20 % of PEG6000 and mannitol). The second test was carried out in nutrient solution BD medium. Our results shows that Both PEG -6000 and mannitol reduced germination. Therefore, a rapid increase was observed in the rate of germination both for the control plants and the plants subjected to a concentration of 5 g/L and 10 g/L and changes in proportion to the time. For the concentration of 15 g/L and 20 g/L, this phase is very short, which explains the reduced germination rate due to the inhibitory effect of the two osmoticums on germination. In this study, PEG-6000 treatments resulted in an increase of some proteins and a decrease of others. Waha displayed 12 bands for control plants, 40 bands for PEG-6000 stressed plants (all treatments) and 35 bands for mannitol treatments.

Olive tree with its main final product, olive oil, is an important element of Mediterranean history, considered the emblematic fruit of a civilization. Despite its wide diffusion and economic and cultural importance, its evolutionary and phylogenetic history is still difficult to clarify. As part of the Mediterranean basin, Algeria was indicated as a secondary diversification center. However, genetic characterization studies from Maghreb area, are currently underrepresented. In this context, we characterized 119 endemic Algerian accessions by using 12 microsatellite markers with the main goal to evaluate the genetic diversity and population structure. In order to provide new insights about the history of olive diversification events in the Central-Western Mediterranean basin, we included and analyzed a sample of 103 Italian accessions from Sicily and, a set of molecular profiles of cultivars from the Central-Western Mediterranean area. The phylogenetic investigation let us to evaluate genetic relationships among Central-Mediterranean basin olive germplasm, highlight new synonymy cases to support the importance of vegetative propagation in the cultivated olive diffusion and consolidate the hypothesis of more recent admixture events occurrence. This work provided new information about Algerian germplasm biodiversity and contributed to clarify olive diversification process.

Survival under stressful circumstance depends on the plant’s aptitude to perceive the stimulus, generate and transmit the signals, and initiate various physiological and biochemical changes. This study aims to evaluate the exogenous seed treatment by abscissic acid (ABA) in durum wheat genotypes under water stress conditions. In this investigation, a hydroponic experiment was conducted to evaluate the potential role of exogenously applied abscicic acid in improving drought tolerance in wheat. Three contrasting wheat genotypes were used in this work: Hoggar, Hedba3 and Sigus. Two levels of water stress were induced: 2h and 4h, the aim of this work was to evaluate the action of seed exogenous treatment with ABA for 8 and 16h on physiological and biochemical parameters like stomatal resistance, antioxidant enzyme activity and quantification of ABA by HPLC. The results showed that water stress caused a decrease in endogenous ABA concentration in the roots of the stressed varieties with the exception of Hedba3. Furthermore, after ABA treatment for 16h, the two genotypes Hedba 3 and Hogar showed a higher accumulation of this phytohormone, compared to Sigus variety which marks a decrease in this concentration and which can be explained by the consumption of the ABA in the defense against the ROS.

Abstract. Rached-Kanouni M, Hani I, Bousba R, Beldjazia A, Khammar H. 2020. Structural variability of Aleppo pine stands in two forests in northeastern Algeria. Biodiversitas 21: 2848-2853. The layout of the stand can be described as the width of the trees, their reciprocal locations, diametric distinction and height. The goal of this study is to recognize changes in the Pinus halepensis spatial and demographic systems in two Beni Oudjana and Chettaba Forests, located in northeast Algeria. An inventory of trees in these forest formations with P. halepensis dominance was carried out based on dendrometric parameters such as total height, tree diameter at dbh ≥ 5 cm, basal area, total volume, etc., as well as the number of trees in the forest. Tree diameter and height measurements were made on 12 rectangular plots (20 m × 20 m), located in both forests. The results obtained show that the mean stand density, mean diameter, basal area and total volume are higher in Chettaba Forest, the values attributed to these parameters are respectively (422 trees/ha, 27.07 cm, 26, 86 m2, 251.63 m3); while the total height and regeneration rate show significantly higher values in Beni Oudjana Forest (18.97 m, 607 individuals/ha). The structure in diameter and height of the species is bell-shaped to asymmetrically positive with a predominance of small diameter individuals in the Chettaba forest. On the other hand, in the Beni Oudjana Forest, the structure is ‘L’ shaped, showing a predominance of very small diameter individuals. These results indicate that the low regeneration rate of P. halepensis in the Chettaba Forest is due to anthropogenic pressures that favor the degradation of this forest.