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1.
Faouzi Lamari Khouadja Sadok Amina Bakhrouf François-Joël Gatesoupe 《Aquaculture International》2014,22(2):699-709
Lactic acid bacteria (LAB) were isolated from rotifer cultures in a marine hatchery to search for potential probiotics for marine animals. Fifteen strains were first selected among a total of 55, according to antibacterial activity against Vibrio sp. Among eight strains identified as Lactobacillus casei, four were highly adhesive, suggesting some ability for surface colonization. The other strains were identified as Lactobacillus plantarum, Lactobacillus dextrinicus, and Leuconostoc sp. To validate probiotic potential, Artemia were challenged against pathogenic Vibrio alginolyticus, with or without one of six selected LAB strains. The six strains protected Artemia against the pathogen, to some extent on condition that nutrient enrichment was provided. La. casei BR51 and X2 were preferred, as they were efficient even in the absence of nutrient supply. La. casei X2 was finally selected as candidate probiotic, due to the best growth performances of Artemia, with or without the pathogen. 相似文献
2.
Molecular markers are a powerful tool with many potential applications in agriculture and forestry. In particular, can provide
information on the relatedness of various clones or varieties that are difficult to distinguish morphologically, thus helping
in the management of plant accessions and in breeding programs. The goal of this study is to genotype 15 clones used in the
Prairie Farm Rehabilitation Administration (PFRA) breeding programs. Simple Sequence Repeat (SSR, or microsatellite markers)
were selected for genotyping using the polymerase chain reaction (PCR). This type of marker is considered the method of choice
due to their abundance, polymorphism and reliability compared to other types of . Sixteen previously isolated and characterized
in aspen (Populus tremuloides) and other poplar species (Populus spp.) were initially tested. Nine markers were selected based on the “informativeness” and the quality of the amplification
products. The nine markers were combined in groups of three to improve the efficiency of the genotyping technique. Using the
nine markers, the average number of alleles per locus was 5.1. The expected and observed heterozygosity ranges were 0.32 to
0.80 and 0.13 to 0.92 respectively. The results also show that it is possible to produce a unique “DNA fingerprint” specific
to each of the 15 hybrid poplar clones with the nine . In this study it was possible to show that two clones, P. ‘Melville’
and P. x ‘Walker’ used in Saskatchewan have similar DNA profiles with nine markers and a combined probability of identity
of 2.23×10−6 suggesting that these clones are identical. This observation will prevent unnecessary duplication of the two accessions in
breeding programs.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
3.
Meyer G Deplanche M Roux D Moulignie M Picard-Hagen N Lyazrhi F Raboisson D Mathevet P Schelcher F 《Veterinary journal (London, England : 1997)》2012,192(2):242-245
A modified-live vaccine has been shown previously to prevent fetal infection with bovine viral diarrhoea virus (BVDV)-2 and, to some extent BVDV-1, when used in association with an inactivated vaccine in a two-step vaccination protocol. In this challenge study, the modified-live vaccine used alone was able to protect 13 heifers between 49 and 96 days of gestation at challenge from leucopenia and virus replication and, for a 4-month period, to prevent fetal infection. The efficacy of the BVDV-1f 22146/Han81 challenge was demonstrated by virus isolation from the fetuses of all nine non-vaccinated, control heifers. However, the small number of heifers tested meant that the vaccination failure rate could be as high as 10% in the field. 相似文献
4.
K. El Fakhouri S. Lhaloui B. Faouzi M. El Bouhssini A. Sabraoui M. Rochd 《EPPO Bulletin》2019,49(2):327-335
Defoliating caterpillars from the family Noctuidae are the most destructive insect pests on spearmint crop in Morocco. To control these pests, the growers apply several applications of non‐selective insecticides that are sometimes not registered for this use. This study investigates the efficacy of a set of selective chemical insecticides and other insecticides registered for organic farming against the defoliating caterpillars for better protection and in order to limit pesticide residues. Two insecticides authorized in organic farming and four other chemical insecticides were tested against the defoliating caterpillars under field conditions, following the randomized complete block experimental design with three replications. The comparative study of the efficacy of the different insecticides tested showed an average caterpillar reduction of 89.4, 82.5 and 68.1% with a defoliation reduction of 57.1, 53.8 and 43.9% for two of the tested synthetic insecticides, chlorantraniliprole (15cc/hl), emamectin benzoate (250g/ha) and for one of the tested bio‐insecticides, spinosad (30cc/hl) respectively. An increase of the total fresh mint weight compared to the non‐treated control was recorded for these three insecticides with 50.9%, 48.4%, and 40.5% for emamectin benzoate, chlorantraniliprole, and spinosad respectively. Insecticides containing chlorantraniliprole, emamectin benzoate, or spinosad active substances could be used as alternatives to other synthetic broad‐spectrum insecticides commonly used on spearmint in Morocco. 相似文献
5.
F. Horchani H. Khayati P. Raymond R. Brouquisse & S. Aschi-Smiti 《Journal of Agronomy and Crop Science》2009,195(4):313-318
The decrease in growth rate of the root system, or the complete cessation of its growth, in fruiting tomato plants is a known phenomena. It has been suggested that a limited supply of carbohydrates to this organ, because of its relative weakness in competition with the developing fruitlets is the main cause for these disorders. This hypothesis was tested in this study with tomato plants ( Solanum lycopersicum cv Micro-Tom) submitted to gradual root hypoxia (1–2 % oxygen) at first flower anthesis and with limited fruit number (six fruits per plant). To this end, a range of physiological and biochemical parameters was evaluated. Our results showed that under oxygen deficiency, root growth was severely affected. In contrast to fruits, root protein and carbohydrate contents decreased significantly, concomitantly with a significant decrease in photosynthesis. Together the present data revealed that, at the fruiting stage, the effect of flooding on root growth and metabolism is probably controlled by the relative sink strength of the fruit. 相似文献
6.
Nitrogen (N) is taken up by most plant species in the form of nitrate (NO ) or ammonium (NH ). Plant response to continuous NH nutrition is species‐dependent. In this study, we compare the responses of tomato (Solanum lycopersicum L. cv. Rio Grande) plants to N source (NO or NH ). To this end, early plant growth, photosynthesis, chlorophyll, carbohydrate, and N‐compound concentrations as well as the activities of main enzymes involved in N metabolism (nitrate reductase, nitrite reductase, glutamine synthetase, and glutamate dehydrogenase) were analyzed. Early plant growth was remarkably ameliorated under NH ‐ in comparison to NO ‐based nutrition. Concomitantly, photosynthetic activity, total chlorophyll, and carbohydrate concentrations were significantly increased. With increasing external NH concentration, NH accumulated mainly in roots. In addition, root protein concentration was significantly increased, reflecting high NH incorporation into organic nitrogen. Root glutamine synthetase (GS) activity was enhanced by NH for concentrations below 5 mM, whereas root glutamate dehydrogenase (GDH) activity increased in parallel to NH availability. Together with the positive effect of NH on tomato plant cv. Rio Grande growth, these results reveal that GDH could have, in addition to GS, a possible role in NH detoxification and tolerance of NH ‐based nutrition. 相似文献
7.
Taoufik Harizi ;Slah Msahli ;Faouzi Sakli ;Mosleh Mekki ;Touhami Khorchani 《农业科学与技术》2014,(5):454-459
In raw materials of dromedary hair, there are two distinct fibre populations： The fine one is of textile relevance and the coarse one is rather worthless and must be as a rule separated prior to spinning and subsequent processing. The fibre surface morphology and fibre fineness of Tunisian dromedary hair has been investigated by means of scanning electron microscope （SEM）. SEM microscopic method provides the fibre diameter, the scale shape, the scale frequency and scale height. The results show that dehaired dromedary fibre presents a relatively low mean fibre diameter （≈ 17 μm） with a high coefficient of variation （CV ≈ 25%）. The scales of the dromedary fibre are on average extremely long and quite visible, they tend not to protrude from the fibre, appear almost convex, and provide a wavy appearance in profile of the relatively coarse fibre. On counting the scale frequency, that is, the number of scale margins within a determined fibre length of 100 μm on the surface of a fine （diameter 〈 30 μm） and coarse （diameter 〉 30 μm） dromedary fibre, comes out roughly five at eight and eight at twelve scale margins, respectively. The mean height of the cuticle scale is 0.12μm and 0.24 μm, respectively, for fine and coarse dromedary fibre. These explain why dromedary fibres present a soft touch due to the prominence of the scale edges. This aspect of the surface structure has a high correlation with the felting capacity of the matter, and contributes to the concepts of handle and gloss. 相似文献
8.
9.
F. Horchani A. Aloui R. Brouquisse & S. Aschi-Smiti 《Journal of Agronomy and Crop Science》2008,194(4):297-303
In order to investigate the effects of root hypoxia (1–2 % oxygen) on physiology and on some fructification parameters of tomato plants ( Solanum lycopersicum cv. H63-5), a range of physiological and agronomic measurements were performed on plants submitted to gradual root hypoxia at the second leaf stage. Stomatal conductance (gs ), total chlorophyll content, leaf area (LA) and leaf mass per area (LMA) were quantified at 14 days of treatment in the first leaf appeared before (L1) and after (L3) root hypoxia application. The results obtained showed that 7 days of treatment has slight effects on plant weight growth. However, 14 days of treatment caused decreased root dry weight (DW) with a concomitant increase in shoot DW. Root hypoxia significantly decreased gs and chlorophyll content of L3, but no effects were noted for L1. LA was significantly reduced for L1 and L3, contrary to LMA which was significantly increased. At the reproductive stage, root hypoxia resulted in a decrease in flower and fruit production, accelerated the entrance in the fruit expansion phase, but did not affect the rate of fruit growth, nor the final fruit size. 相似文献
10.
Asma El Oudiani Ben Sghaier Yassin ChaabouniSlah Msahli Faouzi Sakli 《Industrial Crops and Products》2012,36(1):257-266
This study investigates the effect of NaOH and NaOCl treatments on chemical composition, morphology and crystalline structure of Agave americana L. fibers. These fibers have been subjected to NaOCl and NaOH alkali treatments at different concentrations.The percentages of lignin and hemicellulose show a decrease with alkaline treatments which, in turn, induces a modification of both morphological and crystalline structures.Unit cell dimensions and crystallite size were more affected with NaOH treatment than NaOCl one. This may result from the mercerisation process which occurs with caustic soda treatment.The observed defibrillization on the treated fiber surface proves the dissolution of the non-cellulosic components present in the fiber cell wall by NaOH and NaOCl treatments. These morphological changes may improve the interaction between matrix and fiber in composites. 相似文献