Phenological stage effect on phenolic composition and repellent potential of Mentha pulegium against Tribolium castaneum and Lasioderma serricorne

Objective:To elucidate for the first time the phenological stage effect on polyphenol,flavonoid and proanthocyanidin contents of pennyroyal(Mentha pulegium)as well as their antioxidant capacities and insecticidal potentials against Tribolium castaneum and Lasioderma serricorne.Methods:Crude methanol extracts from pennyroyal(Mentha pulegium)aerial parts were evaluated for their anti radical,reducing power activities and repellent potentials against selected coleopteran insects during different phenological stages.Results:Phenolic contents of pennyroyal aerial parts and their antioxidant effects were significantly dependent on maturity stage of the plant.The maximum of phenol production was reached during the full flowering stage.Apigenin was the major phenol in Mentha pulegium with an amount of6.01 mg/g of dry vegetable matter during this period.Nevertheless,at fructification stage,the highest antioxidant activity was not related to high phenolic content.The repulsive effect of pennyroyal extract showed that Lasioderma serricorne was more susceptible to pennyroyal extract than Tribolium castarneum with corresponding median repellent dose values of 0.124and 0.006 mg/mL respectively.Moreover,great differences in insect repulsion depending on extract concentrations,exposure time and developmental stage was observed.For the lowest concentration(0.125 mg/mL),the repellent effect against Tribolium reached its maximum(90%)during the fructification stage(after 24 h of exposure)while this repellent effect was 80%during the vegetative stage.Conclusions:Due to the strong insecticidal potential of pennyroyal extracts,this study highlights the therapeutic properties of this plant and encourages its use as a safer,environmental-friendly and efficient insecticide in food industry.

氮源用量对杨木白腐菌降解效率的影响

通过调整培养基中氮源的含量,利用白腐菌Phanerochaete chryscoporium和Trametes versicolor对杨木木片处理28 d,分析了木片的质量得率及化学成分的变化.结果表明:当酵母浸出粉的用量为1 g.L-1时白腐菌对原料中的木素降解率最高,在氮源用量相同的情况下,白腐菌Phanerochaete chryscoporium比Tranetes versicolor降解木素的速率更快.

Effect of Indigenous Phytase-Producing Yeast Cultures on Growth Performance, Digestion and Health of Rabbits (Oryctolagus cuniculus)

This study investigated the effects of dietary supplementation of indigenous phytase producing live yeast cultures on growth performance, phytate degradation and blood biochemical parameters of weanling rabbits. Fifty-six rabbits (28 males and 28 females) were allotted randomly into four groups containing a control and three groups administrated each with the yeasts Saccharomyces cerevisiae ADR1B1, Hanseniaspora jakobsenii ADR3E1, Hanseniaspora guilliermondii RD31 during 8 weeks. The results showed that the administration of the three yeast strains accelerated the weight gain and improved rabbits growth performance in comparison to the control group, but did not affect the serum biochemical and hematological parameters. The highest weight gain (1715.95 ± 236 g), and phytate degradation rate (73.82% ± 0.92%) and the lowest biochemical parameters (triglycerides, cholesterol, HDL and LDL) were observed on rabbits fed with the yeast Hanseniaspora jakobsenii ADR3E1. This indigenous yeast species, which is used for the first time in animal feeding provided the best beneficial effects in rabbit breeding. Therefore, based on this finding, Hanseniaspora jakobsenii ADR3E1 can be recommended to supplement rabbit diets for growth performance and profitability enhancement.

<i>In Vitro</i>Germination and Plantlet Establishment of Wild Chamomile of Morocco <i>Cladanthus mixtus</i>(L.) Oberpr. and Vogt

In vitro seeds germination and plantlets establishment of Cladanthus mixtus (L.) Oberpr. and Vogt were studied in this report. A reliable protocol was developed for in vitro seed germination, multiplication and plantlet regeneration of Cladanthus mixtus. The seeds were sterilized and cultured in different media. Among the two basal media evaluated for symbiotic seed germination, gelled distilled water was found to be the best with a high percentage of seeds germination (100%) after 33 hours of culture. Seedlings were further transferred to different types of media. Result observed after 4 weeks showed that MS medium promotes the highest growth with an average of 2.75 ± 0.12 cm shoot length and 2.60 ± 0.29 shoots per explants, and the mean number of roots achieved 3.33 ± 0.17 root per explants with a length of 2.42 ± 0.16 cm. This study showed that macroelements of MS (1962) medium is essential for in vitro shoot multiplication, growth and rooting of shoots of Cladanthus mixtus L.

Allelopathic Effect of Three Wild Plants (<i>Azadirachta indica</i>, <i>Tithonia diversifolia</i>and <i>Thevetia peruviana</i>) on Tomato (<i>Lycopersicum esculentum</i>Mill.) Growth and Stimulation of Metabolites Involved in Plant Resistance

The aim of this study was to determine the allelopathic effects of Azadirachta indica oil and aqueous extracts of Tithonia diversifolia and Thevetia peruviana on the growth and stimulation of metabolites involved in tomato plant resistance. Randomized in blocks within a shaded area, the different treatments prepared at 10% and 15% (v/v and w/v) in water were subsequently applied on tomatoes seeds to monitor the effect on germination, and on tomatoes leaves to monitor the effect on growth and resilience of the plants. The result showed that in stressful conditions all the treatments significantly inhibit (p < 0.05) the germination capacity of the seeds from 21.22% to 92.61%, the germination rate from 39.82% to 92.76% and the germination viability of the seedlings from 64.67% to 100%. However, the negative allelopathic effect of the treatment was significantly reduced (p < 0.05) when used for germination initiation by botanical priming. In addition, while T. diversifolia at 10% promotes a better aerial and root growth in tomato plants, T. peruviana at 15% induces the activation of resistance mechanisms in tomato plants by increasing protein levels to 104.5%, phenol levels to 183.33% and peroxidase enzyme activity to 586.15%. Therefore, allelopathic compound of wild plants would be a good alternative for growth promotion and resistance of tomato crops.

Effect of Cultural Practices on the Growth of Date Palm VitroPlants Planted in Errachidia （South East of Morocco）

In vitro multiplication of date palm is a very promising way for the rehabilitation of Moroccan palm devastated. The objective of this work was to study the development of vitroplants introduced into traditional and modem palm of the Errachidia region. The procedure followed is to make descriptive diagnoses in different sites where the palm was introduced and to evaluate the mortality of plants and cultural practices. The mortality rates varied from 78% to 19% in new plantation depending on the cultivation technique used. At the traditional palm, the rate of recovery ofplantlets was zero. The mortality is higher in Nejda cultivar compared to Boufegouss. This variety also presented a better adaptation in terms of shoot height in comparison with the development of Nejda and Mejhoul varieties. The production of offshoots as well as inflorescences takes place three years after plantation. The importance of improving cultivation techniques in date palm for the development of this sector in Morocco is discussed.

Estimation of the Production Cost of Date Fruits of Cultivar Majhoul (<i>Phoenix dactylifera</i>L.) and Evaluation of the Moroccan Competitiveness towards the Major Exporting Regions in the World

The aim of the present study was to estimate the production cost of dates of cv. Majhoul (Phoenix dactylifera L.) as part of the Moroccan strategy to develop the date palm sector, and to compare it to that reported in the main exporting regions. Data were collected through surveys of farmers and farm owners carried out in the “Meski Boudnib” extension zone during 2018 and 2019, as well as from studies performed by some governmental organizations. The surveys were conducted on 30 modern and productive date palm farms, managed in monoculture and equipped with localized irrigation systems. All fixed and variable costs were calculated. It was found, through our calculations, that the subsidies from the Moroccan government reduce the average investment cost of a modern date palm farm by 56%. It was also shown that the production cost of one ton of date fruits of cv. Majhoul in the extension zone “Meski Boudnib” (Morocco) is estimated at about 6060 MAD (US$ 634.5), out of which 28% represents the labor cost and 23% represents mineral and organic fertilization costs. The findings of the present study revealed that the production cost of one ton of cv. Majhoul dates in “Meski Boudnib” is lower than those reported in the Coachella Valley (20,189 MAD/ton;US$ 2114) and the Jordan Valley (10,536 MAD/ton;US$ 1103).

Effect of Water Stress Induced by Polyethylene Glycol 6000 on Somatic Embryogenesis in Cocoa (<i>Theobroma cacao</i>L.)

Climate change, coupled with insufficient and irregular rains, led to a decline in the productivity of Ivorian cocoa production. The present study aimed to screen three cocoa (Theobroma cacao L.) genotypes in order to evaluate their response to water stress at callus and somatic embryos induction and proliferation stages. Staminode and petal explants of the genotypes C1, C14 and C16 from the collection of National Center of Agronomic Research (CNRA) of Ivory Coast, were placed on medium DKW (Driver & Kuniyuki Walnut) in the presence of different concentrations of Polyethylene glycol (PEG) 6000 (0, 25, 50, 75, 100 and 125 g/l). This polymer was used as osmoticum to stimulate water stress. Data were recorded for callus induction frequency, callus fresh weight, embryogenic callus percentage and average number of somatic embryos. The results obtained showed that intensity of callus proliferation decreased with increasing concentration of PEG 6000. In all genotypes tested, only the petal explants underwent somatic embryogenesis. The induction rates and average number of somatic embryos per explant were reduced with the increase in the concentration of PEG 6000. Among the tested genotypes, C1 produced somatic embryos with all concentrations of PEG 6000 and expressed highest frequencies of induction (62%) and average number of somatic embryos per explant (6.22). This genotype would be the most tolerant to water stress. Somatic embryos obtained with high concentrations of PEG 6000 in this study provide an important basis for the selection and further production of water stress-tolerant varieties of cocoa.

THE SERIAL MODEL IN LIQUID FLUIDIZATION AND ITS LIMITATIONS

The serial model of Epstein et al. （1981） is demonstrated to predict successfully the overall voidage of the mixed layer of incompletely segregated binary and ternary mixtures of liquid-fluidized solids that differ only in shape. Some speculations are then offered on the conditions for the success and failure of this model. Finally, methods proposed in the literature for estimating the deviations from the serial model for a binary-solids bed, which manifest themselves as a bed contraction, are discussed, with emphasis on packing models.

Anaerobic Removal of Trace Organic Contaminants in Sewage Sludge: 15 Years of Experience

Trace organic contaminants (TOCs) correspond to a broad range of molecules generated either directly or indirectly by human activity. Even though TOCs are found at low concentrations in the environment, they often accumulate by biomagnification and bioaccumulation into biological organisms and cause irreversible damages in biological systems through direct or indirect toxic effects such as endocrine disruption and tumour initiation. This manuscript presents the main findings of over fifteen years of research focusing on biological removal of various TOCs found in sewage sludge from urban treatment plants. A special focus of the research was made on microbial processes in complex anaerobic ecosystems. Four families of compounds mostly retrieved in urban plants were studied: the polycyclic aromatic hydrocarbons (PAHs), the polychlorobiphenyls (PCBs), the phthalic acid esters (PAEs), and the nonylphenol ethoxylates (NPEs). It was observed that the microbial capability for removing low amounts of TOCs required a long adaptation time and was often limited by the bioavailability of these compounds. In fact, the overall biodegradation resulted from the numerous interactions existing between the matrix (organic matter) and the microbial ecosystems according to the physico-chemical sorption properties of these compounds. Mechanistic aspects were also tackled in depth and specific models were developed for better understanding the network of interactions between TOCs, microorganisms, and organic matter. These findings could be extrapolated to other ecosystems such as soils and sediments. Finally, it was shown that microbial cometabolism was essential for TOC removal, and the concept of bioavailability was not only dependent on the nature, the level, and the sorption properties of TOCs but was also strongly dependent on the nature and the concentration of the sludge organic matter. Specific parameters were proposed for better evaluating the fate of TOCs in microbial anaerobic processes and technological solutions for efficient removal of these compounds were also proposed.