Spatial and Temporal Distribution of Heavy Metals in Marine Sediment Along the Doha Bay

Concentrations of twenty five heavy metals (Ag, Al, As, Ba, Be, Ca, Cd, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Mo, Na, Ni, Pb, Sb, Se, Sr, V, Zn, and Hg) in surface sediment from ten transects each with five stations were studied. The sediment samples were collected in May and December 2012 in order to examine the spatial and temporal variation and investigate the pollution sources. Significant differences were observed in metal concentrations between the sampling locations and durations. Higher concentrations were observed in areas where there are a lot of anthropological activities. The distribution of selected metals were presented in contour maps showing the variation between the two periods. Moreover, it was observed that December 2012 sampling was significantly higher than May 2012. In order to further study particle size effect on metals uptake, two different grinding times were administered on four randomly selected samples and the results showed no significant difference on the analysis in the ICP-OES instrument. The overall results of metal analyses were within the international standards criteria and the results were comparable to the previous studies conducted around Qatar. A monitoring approach is recommended for the sediment quality assessment. Additional examinations were conducted using contour maps that show the distributions of the metals around Doha Bay during May and December 2012

Biodiversity of Amphipoda Talitridae in Tunisian Wetlands

Although wetlands were remarkable habitats with their fauna and flora diversity, few studies have been devoted to the study of amphipod biodiversity in this ecosystem type. The amphipod communities of six wetland types belonging to 117 stations were studied with respect to species composition, abundance and their relationship with environmental parameters. Amphipods were collected during spring. At each station, eight quadrats of 50 × 50 cm2 were randomly placed. Animals were preserved in alcohol at 70°C. In the laboratory, the specimens collected were identified and counted. Physicochemical parameters (organic matter, particle size, heavy metals) of sampled soils were determined. The results showed that the highest species richness was observed in lagoons with the presence of eight species namely Orchestia montagui, Orchestia gammarellus, Orchestia mediterranea, Orchestia stephenseni, Orchestia cavimana, Platorchestia platensis, Deshayesorchestia deshayesii and Talitrus saltator, whereas in the hill lakes and dams banks, no specimens were collected. The biodiversity of amphipod species depends on climatic (temperature, humidity) and edaphic (organic matter, particle size, heavy metals) factors

Effects of pre-incubation in sheep and goat saliva on in vitro rumen digestion of tanniferous browse foliage

A two-stage in vitro procedure was used for assessing the activity of parotid saliva to enhance rumen digestion of tanniniferous browse foliage. The procedure consisted of pre-incubation in saliva for 4 h at 39 °C followed by incubation in diluted buffered rumen fluid. Using this procedure, a study was conducted to examine the effects of pre-incubation in sheep (SS), quebracho-supplemented sheep (qSS) and goat (GS) parotid saliva or in McDougall’s artificial saliva (AS, used as control) on in vitro rumen fermentation kinetics (estimated using the gas production technique) of browse foliage from six shrub species (Cytisus scoparius, Genista florida, Rosa canina, Quercus pyrenaica, Cistus laurifolius and Erica australis) collected over two seasons (spring and autumn), thus varying the in vitro digestibility (from 0·597 to 0·903) and tannin contents (from3 to 130 g tannic acid equivalent/kg dry matter (DM)). Saliva was collected from four sheep and four goats fed alfalfa hay, and fromfour sheep fed the same alfalfa hay but supplemented with quebracho (rich in condensed tannins) for 60 d, through a cannula inserted in the parotid duct, and rumen fluid was always from sheep fed alfalfa hay. The extent of degradation when browse foliage was pre-incubated in qSS was similar to that observed with control AS (0·449 v. 0·452, respectively), and 8% less than the value with pre-incubation in SS (0·490). In vitro fermentation kinetics (gas production parameters) of browse foliage were not significantly enhanced with pre-incubation in qSS compared with SS, whereas in vitro digestibility and extent of degradation in the rumen were significantly reduced with qSS compared with SS. After pre-incubation in sheep and goat saliva, the extent of browse foliage degradation was significantly increased by 4–8% compared with pre-incubation in the control AS. Fermentation efficiency of browse foliage was increased (P<0·05) with pre-incubation in GS compared with SS. Sheep or goat saliva may have some activity to affect in vitro rumen fermentation of the foliage samples incubated, enhancing extent of degradation of tannin-rich browse. However, a relationship between the magnitude of this effect and the tannin content of the browse foliage could not be established, suggesting that sheep and goat saliva may not be particularly important in neutralizing tannins

In situ degradability of soyabean meal treated with Acacia saligna and Atriplex halimus extracts in sheep

The effects of Acacia saligna (AC) and Atriplex halimus (AT) extracts were evaluated on ruminal soyabean meal (SBM) degradability using the nylon bag technique. Samples of SBM were treated with 0, 4, or 8 g of AC or AT extracts per 100 g SBM. Bags were incubated in two cannulated sheep for 2, 4, 6, 8, 12, 24, and 48 h. The chemical constituents (CCs) of extracts was determined using GC-MS. Rate and potential degradability of dry matter (DM) were decreased (P=0.015) to a greater extent than N degradability (P=0.145) with AC and AT doses. DM and N degradation were decreased (P<0.05) by 15% and 29%; 24% and 47% with AC, and 21% and 29%; 23% and 37% with AT at 4% and 8% for DM and N, respectively. The data suggest the possibility of using these extracts as feed additives to reduce ruminal degradability of SBM in ruminant diets

Phenotyping mediterranean durum wheat landraces for resistance to Zymoseptoria tritici in Tunisia

Durum wheat landraces have huge potential for the identification of genetic factors valuable for improving resistance to biotic stresses. Tunisia is known as a hot spot for Septoria tritici blotch disease (STB), caused by the fungus Zymoseptoria tritici (Z. tritici). In this context, a collection of 3166 Mediterranean durum wheat landraces were evaluated at the seedling and adult stages for STB resistance in the 2016–2017 cropping season under field conditions in Kodia (Tunisia). Unadapted/susceptible accessions were eliminated to reach the final set of 1059 accessions; this was termed the Med-collection, which comprised accessions from 13 countries and was also screened in the 2018–2019 cropping season. The Med-collection showed high frequency of resistance reactions, among which over 50% showed an immune reaction (HR) at both seedling and adult growth stages. Interestingly, 92% of HR and R accessions maintained their resistance levels across the two years, confirming the highly significant correlation found between seedling-and adult-stage reactions. Plant Height was found to have a negative significant effect on adult-stage resistance, suggesting that either this trait can influence disease severity, or that it can be due to environmental/epidemiological factors. Accessions from Italy showed the highest variability, while those from Portugal, Spain and Tunisia showed the highest levels of resistance at both growth stages, suggesting that the latter accessions may harbor novel QTLs effective for STB resistance

Chemical composition, antioxidant, and antimicrobial activities of Leaves of Ajuga iva

The main objective of this research was to study the biological characteristics in terms of antioxidant and antimicrobial activities of Ajuga iva and determine the best analytical and extraction methods applicable to this specie and studied compounds. A short screening of its nutritional value in terms of chemical composition is also included. A. iva leaves were analyzed for crude protein (CP), cell wall [neutral detergent fiber (NDF), acid detergent fiber (ADF), and acid detergent lignin (ADL)], minerals, fatty acids, essential oils, and phenolic compounds. Mature aerial parts of A. iva were randomly collected during the Spring season from Mograne-Zaghouan, Tunisia. Leaves of A. iva contained 13.4 ± 0.4% CP, 26.3 ± 0.35% NDF, 20.2 ± 0.42% ADF, and 5.13 ± 0.21% ADL. Mineral content (13.0 ± 0.45%) was mainly composed of potassium (4.5% g DM) and magnesium (4.25% DM). Leaves of A. iva had linolenic (26.29 ± 0.760%) and linoleic (37.66 ± 2.35%) acids as the main components of the acid profile. Thymol was found to be the most dominant (23.43%) essential oil, followed by 4-vinylguaiacol (14.27%) and linalool (13.66%). HPLC-PDA-ESI-MS/MS analysis pointed out the presence of phytoecdysteroids. Phenolic acids and flavonoids, such as glycosylated derivatives of naringenin, eriodyctiol, and apigenin, were detected in the methanol extract of A. iva leaves. Our results underline the importance of choosing proper extraction methods and solvents to extract and characterize the described compounds profile of A. iva leaves. Results also show A. iva leaves as a potential source of functional ingredients with beneficial health-promoting properties. Overall, leaves of A. iva have low biological activities (antioxidant and antimicrobial activities) with a chemical composition suitable as a feed for ruminants in rangeland pasture. It also has low-grade antibacterial or medicinal characteristics when fed to ruminants

Insights into the phytochemical composition of selected genotypes of organic kale (Brassica oleracea L. var. acephala)

Seven genotypes of kale (B. oleracea L. var. acephala), selected from a collection set up in the framework of the BRESOV H2020 Project, aimed at breeding under organic conditions, were analysed for the content in the characteristic phytochemicals of Brassica spp. The presence of prebiotic oligosaccharides was an important characteristic of this crop, with values ranging from 4.2 to 10.8 g/100 g d.w. The other detected soluble sugars were sucrose, glucose, and fructose, with glucose predominating (3.9–9.0 g/100 g d.w.). Sulphur compounds, such as sulphoxides, were detected in the form of pyruvic acid, their catabolic product (36–154 mg/100 g d.w.). In addition, the levels of main breakdown products of glucosinolates, such as sulforaphane and indole-3-carbinol, were found to be in average contents of 6.7 and 3.9 μmol/g d.w., respectively. Finally, the presence of major phytochemicals in kale, such as polyphenols and carotenoids, reported considerable concentrations (around 1400 mg/100 g d.w. and 19 mg/100 g d.w, respectively), typical for this Brassica crop

Nutritive Value of Ajuga iva as a Pastoral Plant for Ruminants: Plant Phytochemicals and In Vitro Gas Production and Digestibility

This study aims to evaluate the nutritive value of Ajuga iva (A. iva) harvested from three distinct altitude regions in Tunisia (Dougga, Mograne, and Nabeul). The chemical composition, phenolic concentration, gas production, and in vitro dry matter (DM) digestibility were determined. The highest concentrations of neutral detergent fiber (NDF) and acid detergent fiber (ADF) were for A. iva cultivated in Nabeul. In contrast, the highest crude protein (CP) concentration was observed in that cultivated in Mograne, and the lowest (p < 0.01) CP concentration was noted in that cultivated in Dougga. Additionally, the cultivation regions affected the concentrations of free-radical scavenging activity, total flavonoids, and total polyphenols (p < 0.01). The highest free-radical scavenging activity was observed with A. iva cultivated in Dougga and Mograne. The highest (p < 0.05) gas production rate and lag time were observed in A. iva cultivated in Mograne and Nabeul regions. DM digestibility differed between regions and methods of determination. The highest (p < 0.01) DM degradability, determined by the method of Tilley and Terry and the method of Van Soest et al., was for A. iva cultivated in Mograne and Dougga, while the lowest (p < 0.01) value was recorded for that cultivated in the Nabeul region. Likewise, metabolizable energy (ME) and protein digestibility values were higher for A. iva collected from Mograne region than that collected from the other sampling areas. In conclusion, the nutritive value of A. iva differed between regions. Therefore, care should be taken when developing recommendations for using A. iva in an entire region. Season- and region-specific feeding strategies for feeding A. iva are recommended

Effect of Exogenous Fibrolytic Enzymes Supplementation or Functional Feed Additives on In Vitro Ruminal Fermentation of Chemically Pre-Treated Sunflower Heads

peer reviewedThis study aims to provide possible utilization of sunflower head byproduct (SFH) as a feedstuff by implementing chemical pretreatments (4% sodium hydroxide (SFHNaOH) or 4% urea (SFHurea) and supplementation with either exogenous fibrolytic enzymes (EFE) or functional feed additive (FFA). The experimental EFE was a complex (1:1, v/v) of two enzyme products with high activity of β-1,3-1,4-glucanase and endo-1,4-β-D-xylanase and applied at 0 (SFHout), 1, 2, 5, and 10 µL/ gdry matter, while FFA was a fermentation byproduct rich in cellulase and xylanase activities, applied at 0 (SFHout), 0.5, 1, 2, and 4 mg/g DM. SFHurea had the highest (p < 0.05) crude protein (CP) content compared to other SFH substrates. Linear enhancements (p < 0.05) in kinetics of gas production (GP), metabolizable energy (ME), organic matter digestibility (OMD) and total short-chain fatty acids (SCFAs) concentrations were observed for all SFH substrates supplemented with EFE. The SFHout had the highest (p < 0.05) potential GP, maximum rate (Rmax) of GP, ME, OMD and SCFAs. Supplementation of EFE was more pronounced than FFA in affecting the kinetic parameters of in vitro GP for all SFH substrates. SFHout supplemented with EFE seems to be the most promising substrate to enhance microbial fermentation in vitro

Improved control of Septoria tritici blotch in durum wheat using cultivar mixtures

Mixtures of cultivars with contrasting levels of disease resistance are capable of suppressing infectious diseases in wheat, as demonstrated in numerous field experiments. Most studies focused on airborne pathogens in bread wheat, while splash-dispersed pathogens have received less attention, and no studies have been conducted in durum wheat. We conducted a two-year field experiment in Tunisia, a major durum wheat producer in the Mediterranean region, to evaluate the performance of cultivar mixtures in controlling the polycyclic, splash-dispersed disease Septoria tritici blotch (STB) in durum wheat. To measure STB severity, we used a novel, high-throughput method based on digital analysis of images captured from 3074 infected leaves collected from 42 and 40 experimental plots on the first and the second year, respectively. This method allowed us to quantify pathogen reproduction on wheat leaves and to acquire a large dataset that exceeds previous studies with respect to accuracy and statistical power. Our analyses show that introducing only 25% of a disease-resistant cultivar into a pure stand of a susceptible cultivar provides a substantial reduction of almost 50% in disease severity. However, adding a second resistant cultivar to the mixture did not further improve disease control, contrary to predictions of epidemiological theory. Susceptible cultivars can be agronomically superior to resistant cultivars or be better accepted by growers for other reasons. Hence, if mixtures with only a moderate proportion of the resistant cultivar provide similar degree of disease control as resistant pure stands, as our analysis indicates, such mixtures are more likely to be accepted by growers