Volume 01 - Issue 02

Full issue

 

Articles

Resistance of Bradyrhizobium sp. (Lotus) to metallic stress 

Hoceme DEGAÏCHIA, Ahmed Ramzi BOUSSAHOUA & Touati BAKRIA

Abstract : The objective of this study is to characterize the bacterial strain Bradyrhizobium sp. (Lotus) and to determine its resistance to trace metal elements (TM) such as copper (Cu(II)) and cadmium (Cd(II). Bradyrhizobium sp. (Lotus) was isolated from nodulated plants of Lotus ornithopodioïdes. Different characteristics of the strain were evaluated, such as growth, bacterial mobility, enzyme and polysaccharide production. The minimum inhibitory concentration (MIC) of TM was determined in vitro and in silico by measuring the optical density at a specific wavelength. The isolate is identified as Bradyrhizobium sp. (Lotus ), which is a Plant Growth Stress Regulating Bacteria (PGSRB) Gram-negative and slow growing, producing succinoglycan, mobile, possessing urease activity. The isolate produces Indole Acetic Acid (IAA) at 70.6 µg/ml. Bradyrhizobium sp. (Lotus) showed more pronounced resistance to Cd(II) compared to Cu(II). The MIC of Cd(II) was estimated in silico to be approximately 10 gL -1 , while the MIC of Cu(II) was 2 gL -1 . Statistical analyzes confirmed a significant relationship between the concentration of TM and the number of bacterial cells. This study made it possible to characterize the bacterial strain Bradyrhizobium sp. (Lotus) and determine its resistance to TM. The results suggest that this strain can be used in remediation or bioremediation applications involving environments contaminated with heavy metals such as copper and cadmium.

Keywords : Lotus ornithopodioïdes L., Heavy metals, Phytoremediation, Rhizobacteria, PGPR

Submitted on: 18-04-2024 | Published on: 12-05-2024


Influence of biochar on soil physicochemical traits and Triticum durum L. physiology during abiotic stress 

Louai GOUASMIA

Abstract : Improving soil nutrient reserves through effective land management practices and pasture utilization is a continuing focus in agricultural discussions. Among the various methods aimed at boosting crop productivity, the use of mineral or organic fertilizers is prominent. Biochar, a carbon-rich substance derived from the pyrolysis of organic residues, is commonly employed as a soil amendment to enhance fertility and improve soil characteristics. This study aims to evaluate the impact of biochar on soil physicochemical properties and the yield of a vital forage crop: durum wheat. Three different doses of biochar were applied (D0 = 0g of biochar, D1 = +20g/pot, and D2 = +60g/pot), in conjunction with two types of water and salt stress. Water stress levels were categorized into four stages (S1 = 100%, 80%, 40%, and 20% of field capacity), while salt stress was administered at three varying concentrations: S0 = 0g of NaCl/l, 4g of NaCl/ l, and 9g of NaCl/l. The results indicate an increase in pH (7.77) and electrical conductivity (1369.13 µS/cm), accompanied by a noticeable improvement in nitrates (7.36 mg/g of soil). Significant increases were also observed in total carbon (2.83%) and soil moisture (8.81%), along with a substantial accumulation of active limestone (3.60%). The plant's response to biochar was particularly notable, especially in terms of chlorophyll levels (3.88µg/g FW) and leaf water content (45.54%)

Keywords: Biochar, durum wheat, soil fertility, drought stress, salt stress.

Submitted on: 13-04-2024 | Published on: 01-09-2024


Characterization of aleppo pine (Pinus halepensis) needles in the Sénalba forest: interaction with insect pests 

Sara HEZIL, Hoceme DEGAICHIA, Gahdab CHAKALI

Abstract: This study investigates the phytochemical characterization of Aleppo pine (Pinus halepensis) needles from the Sénalba forest in Djelfa, Algeria, focusing on their interaction with invasive forest pests. Qualitative phytochemical tests were performed on lyophilized needle powder to assess secondary metabolite composition, revealing notable differences between needles used as oviposition sites and those that were not. The analysis identified high levels of tannins (catechic and gallic) and flavonoids in needles as sociated with oviposition, indicating their potential role in attracting pest females. Terpenes and sterols were moderately present across all samples, while saponins were more abundant in reforested areas where oviposition occurred. Alkaloids, however, were consistently absent. These findings align with previous research demonstrating the richness of P. halepensis in phenolic compounds, influenced by various factors such as geographic location, environmental conditions, and extraction methods. The antioxidant and enzyme-inhibitory properties of flavonoids, along with the protective and regenerative effects of tannins, appear to contribute to their ecological significance. These compounds may act as olfactory cues, making reforested monocultures more detectable to pest females compared to mixed natural forests. This research highlights the critical role of secondary metabolites in host-plant selection by invasive pests and provides a foundation for further studies aimed at enhancing forest pest management strategies.

Keywords : Algeria, Forestphytochemical characterization, Pinus halepensis

Submitted on: 14-07-2024 | Published on: 03-09-2024


Khadidja BENMAIZA, Hamida MALLEM

Abstract: Seed dormancy in plants can be caused by various factors, with the seed coat (tegument) being a significant barrier, especially in species like Acacia. Our study aims to find the optimal conditions for germination of Acacia saligna seeds, where these seeds were subjected to two periods of scarification with 96% concentrated sulfuric acid plus control which make three groups (the first group control, the second group 20 min, the last group 60 min of scarification) the seeds were then divided into two groups to germinate at two different temperatures: 15°C and 25°C. Germination was followed in lab for 20 days. Then we performed measurements of germination performance parameters (germination rate, vigor index, median germination time). Our results showed that the best germination rate and speed of Acacia saligna seeds was seed subject chemical scarification for 60 min and germinated at 15 ° C, whereas, the seeds that managed to germinate at 25 ° C showed greater root elongation. Finally, we were able to conclude that A. saligna prefers coolness for germination and higher temperatures for growth.

Keywords : Acacia saligna ; germination ; scarification ; temperature ; tegument

Submitted on: 27-10-2024 | Published on: 28-01-2025


Popularization of rural families by the High Commission for the Development of the Steppe with regard to the cultivation of oyster mushrooms.

Kheira BAKRIA, Zahra BOUABDELLI ROBA 

Abstract: This study, involves organizing educational, theoretical, and practical training sessions on the cultivation of gray oyster mushrooms. (Pleurotus ostreatus). The objective is to improve and diversify the incomes of rural families, farmers, and livestock breeders, who have been negatively affected by desertification and its consequences. The choice of this crop is based on the importance of the mushroom, its ease of production, and the increasing demand in restaurants and shops, thanks to its nutritional and health benefits. This initiative was carried out in collaboration with the mayors of certain municipalities and involved nearly 200 beneficiaries, both men and women. Three provinces (Djelfa, Saïda, Aïn Témouchent) were affected by the outreach, with variable participation according to gender and age. The theoretical and practical training showed overall interest, but a low rate of practical application

Keywords : Popularization, cultivation, gray oyster mushrooms, rural families, income

Submitted on: 12-12-2024 | Published on: 28-01-2025