Nicotiana Glauca Graham (Solanaceae) Bioactivity and Toxic Effects on Mortality, Feeding Behavior and Pupation Choice of Drosophila Melanogaster Larvae (Diptera: Drosophilidae)

Nicotiana glauca is a medicinal plant used by traditional healers as antibacterial, antifungal, antiviral and anti-inflammatory medicines. The leaves of N. glauca are very rich in indolic alkaloids which give it a larvicidal power which allows us to use it as a bio-insecticide.In the present study we were perfomed in the direct (mortality) and indirect (food attractiveness and pupation) toxic effects of the aqueous extract of N. glauca on the mortality and feeding behavior of the fruit fly Drosophila melanogaster. The treatment was administered to 2nd instar larvae (L2) and the mortality rate was monitored for 15 days. Similarly we treated the 2nd instar larvae (n=50) with a sub-lethal concentration of 25µg/ml. Two days after the treatment the third instar larvae of D. melanogster are exposed to two nutrient media (control and treated with N. glauca) and the choice of the larvae is noted during one hour of time.The findings show that after 15 days of treatment, mortality rates in D. melanogaster larvae can reach 50%, as we observed a disruption in olfactory and gustatory signals, with both control and treated larvae preferring the food preparation mixed with the aqueous extract of N. glauca Graham and losing their ability to smell their control medium. This indicates that the bioactive chemicals isolated from this poisonous plant are mostly appealing allelochemical substances

PHYSICAL AND CHEMICAL CHARACTERIZATION OF OUED MEBOUDJA (ANNABA)

Water pollution is a concept that is constantly evolving. It constitutes today a real threat for the environment and of course for the health of the man. The objective of this study is to evaluate the quality of surface waters of oued Meboudja (Annaba- Algeria) and to characterize the different types of pollution while the composition of water plays an important role in determining its quality. As objective, this work consists at the beginning to realize a monthly follow-up in three sites (S1, S2, S3) of sampling in all the length of the Oued Meboudja (upstream, center and downstream), during the period of January to December 2020, with a complete analysis of the physicochemical parameters such as (Temperature, potential hydrogen, Electric Conductivity, biochemical oxygen demand, Dissolved oxygen, Nitrite, Nitrate, Chloride, Ammonium, Suspended solid, Sodium, fatty oils, turbidity). The results showed in the three sites (S1 upstream, S2 center, S3 downstream) that temperature ranged between 11°C and 18°C. Means of pH ranged between 7 and 9. Conductivity in our finding raged between about 1064 to 2300 µs/cm. Biochemical oxygen demand ranged between about 9.30 and 13.30 mg/l. Dissolved oxygen also balanced between 1.50 and 2.03 mg O2/l. Nitrite in this study ranged between 1.50 and 2.02 mg/l. Nitrate ranged between about 41 to 52 mg/l. Chloride ranged between 71 to 81 mg/l. Ammonium through the year ranged between 1.66 to 2.30 mg/l. Suspended matter ranged between 153 to 190 mg/l. Sodium ranged between 6 to 6.60 mg/l. fatty oils ranged between 95 to 115 mg/l. Finally turbidity ranged between 8 to 16 NTU. The highest means were observed in the summer (especially in August) of all parameters but the turbidity which augmented significantly in the winter (December to January). Waters of Oued Meboudja are loaded by various pollutants of several origins namely: industrial, chemical and also agro-food

Study of Soil-Vegetation Relations in the Edough Peninsula (North East of Algeria)

This study aims to determine the relationships likely to exist between the edaphic variables and the abundance of oak species in the Edough forest of the commune of Seraidi (North East of Algeria), a humid bioclimatic stage where rainfall is abundant. In order to characterize the properties of the soils of the Edough forest (Seraidi) and to verify the usefulness of the fractionation of organic matter in a forest ecosystem, we have established a prospecting sampling plan based on a topographic background of the superposition of the different plant groups. In this context, the approach we adopted consisted on three main steps (i) a stratified sampling of the soil, (ii) the determination of the different strata of vegetation, (iii) describing the soil on which these plant formations settle and develop. Our results revealed that the soils of the Edough forest are acidic to very acidic and non-saline. It is also characterized by clayey texture that is not very permeable, with a high rate of organic matter, which controls the buffering capacity of the soil. The characterization of the soils allowed determining three types of plant formations and thus three types of soils where pedogenesis is under direct control of the supply of organic matter. The relationship between the soil and the vegetation in this forest is clearly close. It is mainly controlled by the supply of organic matter, which shows a significant dynamic and evolution. On the other hand, the climatic conditions and the type of plant formations have a capital role in the mineralization of the existing organic matter

Satellite and In Situ Detection of Air Pollution in Urban Area – Case Study of El Eulma Town (North East of Algeria)

The use of plants along roads can be consider to improve roadside air quality and to reduce human exposure to drust. Besides, the majority among of the drusts are accumulated on their leaves, that’s why they are used as an indicator to estimate the air quality. This work illustrates the interest of the urban vegetation and satellite data to detect the air pollution in the town of El Eulma which located in the North East of Algeria. To achieve this, the use of remote sensing plays a significant role in studying the temporal and spatial distribution of air pollution, as well as its impact on the ecosystem througout Normalized Pigment Chlorophyll Ratio Index (NPCI). In the other hand, the analysis of leaves of most dominant plants make it possible to understand the air quality in this region. Four species are selected from different plots in the study area as well as : nerium (Nerium oleander), planetree (Platanus acerifolia), wax-leaf privet (Ligustrum japonicum) and white mulberry (Morus alba). The obtained results show that the ratio fresh matter/dry matter of leaves varied from site to another which is very weak in places marked by high anthropic action. Also, the statisical analysis found that this ration is very important in planetree and white mulberry. The high concentration in dust registered in nerium leaves contributes to the decrease of the ratio fresh matter/dry matter in this species. The results of NPCI are verry weak in nerium compared to other species, while a very large amount of dust has been recorded on their leaves, which prevents the photosynthetic reaction. The findings of this work might contribute to the plant species selection for urban vegetation and the important of the use of NPCI index in evaluation of the pollution intensity which accord to the results of the ratio fresh matter/dry matter

Evaluation of the Toxic Effects of Aqueous Extracts of Solanum Nigrum L.( Solanaceae ) on the Mortality and Development of Drosophila Melanogaster (Diptera : Drosophilidae).

Solanum nigrum is a plant that has therapeutic properties of the Solanaceae family. It is used extensively in traditional medicine but also as a bio-insecticide to control insect pests. Some parts of this plant can be very toxic to livestock and humans. In the present study, the direct and delayed toxic effects of aqueous extracts of S. nigrum on the mortality and development of Drosophila melanogaster were investigated. For this study, an extraction method including decoction is adopted to extract the active principles from the leaves of S. nigrum. The treatment was carried out by ingestion on 2nd instar larvae (L2) and adults. The exposure to the aqueous extract shows that it has a good insecticidal activities, it acts on the larvae by inducing 96.25 % mortality rate at the end of treatment by 50g/l. The adults’ mortality increases with the lengthening of the exposure time as well as with the dose increase. The maximum mortality was recorded is between 97.50% and 100% in males and females. We also recorded a disturbance in the flies development, which took less time to reach the adult stage when they were treated, and this for the five concentrations. Malformations were recorded in the adult wings after treatment with the different concentrations of the toxic plant. In addition, some flies showed a significant increase in size compared to controls