Trueness-to-type and agronomic characteristics of Coffea arabica trees micropropagated by the embryogenic cell suspension technique     

Etienne H  Bertrand B 《Tree physiology》2001,21(14):1031-1038

Trueness-to-type and agronomic characteristics of trees of four coffee (Coffea arabica L.) F(1) hybrid clones derived from embryogenic cell suspensions were compared with those of trees produced from in vitro microcuttings. Three types of variants were observed among the 644 trees derived from embryogenic suspensions. Total frequency of the variants was 2.1% for trees originating from embryogenic cell suspensions, whereas no variant was found among the trees produced from microcuttings. The variant known as "thick leaf" had thick leaves, many abnormally starry flowers and low yields of large fruit. The "dwarf" variant was characterized by slow growth and small fruit. The "dwarf peaberry" variant had abnormal seeds in a single cavity, in addition to the "thick leaf" and "dwarf" characteristics. Compared with normal trees, the variants differed in leaf density and number of chloroplasts per guard cell. The variants aside, there were no differences in the main agronomic characteristics between trees produced from embryogenic suspensions and those produced from microcuttings. For all four clones, the trees had vegetative characteristics, productivity, fertility, and bean biochemical, mineral and organoleptic characteristics that were identical to those of the controls. We conclude that it is possible to generate coffee trees commercially with normal agronomic performance from embryogenic suspensions, because the frequency with which somaclonal variants occur is limited.  相似文献   

Interactive effects of P-Cu fertilizers on growth and mineral nutrition of maritime pine     

Etienne Saur 《New Forests》1993,7(2):93-105

The interaction between copper and phosphorus was studied in a pot experiment involving a factorial combination of three levels of copper and three levels of phosphorus applied to maritime pine seedlings growing in podzolic sand.Biomass measurement showed that a single copper fertilization could be toxic to the plant and that better growth was obtained with a combination of both phosphorus and copper fertilization. Copper toxicity was shown to be dependent on phosphorus levels in the plant, and better growth was obtained with an appropriate balance between phosphorus and copper concentrations. A reciprocal inhibition between phosphorus and copper uptake was assumed to explain this pattern.  相似文献   

Flavored yogurt complex viscosity influences real-time aroma release in the mouth and sensory properties     

Saint-Eve A  Martin N  Guillemin H  Sémon E  Guichard E  Souchon I 《Journal of agricultural and food chemistry》2006,54(20):7794-7803

The influence of flavored yogurt texture on aroma perception and in-nose aroma release measured by atmospheric pressure chemical ionization mass spectrometry analysis was investigated. The study was carried out on six yogurts varied by protein composition and mechanical treatment. For the same matrix composition, the complex viscosity of yogurts influenced in-nose release and perception. After swallowing, aroma release and intensity of olfactory perception were stronger in low-viscosity yogurts than in high-viscosity yogurts. Moreover, the protein composition influenced aroma release only when yogurts exhibited wide variations of complex viscosity and consequently texture. In mouth, aroma release and perception were influenced more by yogurt mechanical treatment than by protein composition. On the basis of mass transfer analysis, the main physical mechanism which could explain the difference in aroma release would be the surface exchange area developed in the mouth and in the throat.  相似文献   

Global network reorganization during dynamic adaptations of Bacillus subtilis metabolism     

Buescher JM  Liebermeister W  Jules M  Uhr M  Muntel J  Botella E  Hessling B  Kleijn RJ  Le Chat L  Lecointe F  Mäder U  Nicolas P  Piersma S  Rügheimer F  Becher D  Bessieres P  Bidnenko E  Denham EL  Dervyn E  Devine KM  Doherty G  Drulhe S  Felicori L  Fogg MJ  Goelzer A  Hansen A  Harwood CR  Hecker M  Hubner S  Hultschig C  Jarmer H  Klipp E  Leduc A  Lewis P  Molina F  Noirot P  Peres S  Pigeonneau N  Pohl S  Rasmussen S  Rinn B  Schaffer M  Schnidder J  Schwikowski B  Van Dijl JM  Veiga P  Walsh S  Wilkinson AJ  Stelling J  Aymerich S 《Science (New York, N.Y.)》2012,335(6072):1099-1103

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Alphaherpesvirus infections in semidomesticated reindeer: A cross-sectional serological study     

Carlos G. das Neves  Julien Thiry  Eystein Skjerve  Nigel G. Yoccoz  Espen Rimstad  Etienne Thiry  Morten Tryland 《Veterinary microbiology》2009,139(3-4):262-269

Alphaherpesviruses infect a wide range of animal species and cause diseases. Cervid herpesvirus 2 (CvHV-2) was originally isolated from reindeer in Finland but the impact of CvHV-2 infections on reindeer remains unclear. CvHV-2 infection could be partly responsible for calf losses as there are indications that it is associated with abortions and neonatal diseases. Previous serosurveys of reindeer (Rangifer tarandus tarandus) have shown that an alphaherpesvirus is circulating among reindeer in Norway. The aim of the present study was to determine the prevalence of CvHV-2 infection among reindeer in various herding districts in Finnmark, the largest reindeer area in Norway, and to identify factors associated with becoming infected with CvHV-2. A total of 3062 serum samples were tested using an ELISA and a sub-set of samples was further tested using a seroneutralization test. The ELISA revealed that 49% of samples were positive. Extrapolation of the results to the total population (111,350 animals; 66% of the Finnmark reindeer population) showed that the seroprevalence in the population was 48%. Seroprevalence varied from 7.6% to 90.7% between districts and was affected by age, weight and population density. ELISA-positive samples neutralized CvHV-2 at serum dilutions greater than those required for neutralization of bovine herpesvirus type 1. It is concluded that CvHV-2 is endemic throughout the reindeer herding districts of northern Norway.  相似文献   

Dietary fiber for pregnant sows: influence on sow physiology and performance during lactation   总被引：1，自引：0，他引：1  

Quesnel H  Meunier-Salaün MC  Hamard A  Guillemet R  Etienne M  Farmer C  Dourmad JY  Père MC 《Journal of animal science》2009,87(2):532-543

This study was conducted to investigate the effects of feeding sows a bulky diet during gestation on their physiological and metabolic adaptations during the peripartum period, and to determine how these effects may relate to sow and piglet performances. From d 26 of gestation until farrowing, gilts were fed diets that contained 2.8 or 11.0% crude fiber (control and high-fiber diets, respectively, n = 9/group). Daily feed allowance provided the same amount of DE daily (33 MJ of DE/d). Throughout lactation, sows were allowed to consume a standard lactating sow diet ad libitum. Litters were standardized to 12 piglets beyond 48 h after birth. On d 105 of gestation, a jugular catheter was surgically implanted. Preprandial blood samples were collected from d 109 of gestation to the day after farrowing and on d 4, 18, and 26 of lactation. Meal tests and glucose tolerance tests were performed on d 109 of gestation and d 4 and 18 of lactation. During gestation, BW and backfat gain did not differ between treatment groups. During lactation, sows fed the high-fiber diet ate an average of 0.94 kg/d more than control sows (P < 0.02). Piglets born from sows fed the high-fiber diet grew faster than piglets from control sows (P = 0.03). Body weight and backfat losses did not differ between the 2 treatment groups. Sows fed the high-fiber diet during gestation had lesser concentrations of leptin before farrowing than control sows (P < 0.01). Leptin concentrations were negatively correlated with feed intake during lactation (P < 0.05). The prepartal increase in prolactin concentrations tended to be greater in sows fed the high-fiber diet than in control sows (P < 0.1). Preprandial concentrations of glucose, NEFA, lactate, and IGF-I fluctuated over time without significant treatment effect. Glucose half-life was shorter in late gestation than during both stages of lactation, but did not differ between sows in the 2 groups. In late gestation, the postprandial increases in glucose and insulin were delayed, and smaller, after a high-fiber meal than after a control meal. During lactation, glucose and insulin profiles after a standard meal did not differ between sows from treatment groups. In conclusion, the greater appetite of lactating sows fed a high-fiber diet during gestation does not seem related to changes in glucose and insulin metabolism and may be partly due to decreased secretion of leptin. The greater feed consumption was accompanied by a faster growth rate of piglets without sparing effect on maternal body reserves.  相似文献   

Bordetella bronchiseptica infection in cats. ABCD guidelines on prevention and management     

Herman Egberink  Diane Addie  Sándor Belák  Corine Boucraut-Baralon  Tadeusz Frymus  Tim Gruffydd-Jones  Katrin Hartmann  Margaret J. Hosie  Albert Lloret  Hans Lutz  Fulvio Marsilio  Maria Grazia Pennisi  Alan D. Radford  Etienne Thiry  Uwe Truyen  Marian C. Horzinek 《Journal of Feline Medicine and Surgery》2009,11(7):610-614

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Climatic significance of glacier retreat and rockglaciers re-assessed in the light of cosmogenic dating and weathering rind thickness in Clarée valley (Briançonnais,French Alps)     

Etienne Cossart  Monique Fort  Didier Bourles  Julien Carcaillet  Romain Perrier  Lionel Siame  Régis Braucher 《CATENA》2010

Recent advances in geochronology provide opportunities to identify the glacial and periglacial sequences in mountain area. In this paper, we focus on the Upper Durance catchment (Southern French Alps), in the Clarée valley, where no absolute chronological benchmark was defined. Glacial remnants and periglacial features were investigated, integrated within a chronological scenario thanks to relative (weathering rind thickness) and absolute (CRE technique) dates. We find evidence of the existence of a Late-Glacial valley glacier, that has never been reported before. Then the upper valleys became ice-free during a period corresponding to the Early-Holocene Climate Optimum, whereas two sequences of cirque glaciation are identified during the second half of the Holocene. We also show evidence of three main generations of rockglaciers, which also mainly developed during the second half of the Holocene, probably at the end of the Subboreal period. The location and the altitudes of rockglaciers are strongly dependent on the geomorphic setting (especially the location of the sediment sources), hence complicating their palaeo-climatic interpretations.  相似文献   

Conservation of species interaction networks     

Jason M. Tylianakis  Etienne Laliberté  Jordi Bascompte 《Biological conservation》2010,143(10):2270-2279

Recent work has shown that antagonist (e.g. predator-prey food web) and mutualist (e.g. pollinator-plant) network structure can be altered by global environmental change drivers, and that these alterations may have important ecosystem-level consequences. This has prompted calls for the conservation of network structure, but precisely which attributes of webs should be conserved remains unclear. Further, the extent to which network metrics characterise the spatiotemporally-variable dynamic structure of interacting communities is unknown. Here, we summarise the attributes of web structure that are predicted to confer stability or increased function to a system, as these may be of greatest interest to conservation biologists. However, empirical evaluation of these effects is lacking in most cases, and we discuss whether stability is even desirable in all contexts. The incorporation of web attributes into conservation monitoring requires that changes in these attributes can be recorded (sampled) with relative ease. We contrast the sensitivity of metrics to sampling effort, and highlight those (such as nestedness and connectance) that could easily be incorporated into conservation monitoring. Despite our growing understanding of the characteristics of food webs that confer stability and function, numerous practical challenges need to be overcome before the goal of conserving species interaction networks can be achieved.  相似文献   

The functional structure of ectomycorrhizal communities in an oak forest in central France witnesses ancient Gallo-Roman farming practices     

Abdala G. Diedhiou  Jean-Luc Dupouey  Etienne Dambrine  Jean Garbaye 《Soil biology & biochemistry》2010,42(5):860-862

The activities of nutrient-mobilising enzymes secreted by ectomycorrhizas of sessile oak (Quercus petraea) have been measured in 24 plots in a forested area in central France where many rural Gallo-Roman settlements (first to fifth centuries AD) have been discovered. Data have been related with tree growth and soil chemical properties. Although soil near the past settlements is still enriched in N and P, this does not always correspond to the higher productivity of oak trees. However, when this is the case, the ectomycorrhizal community displays higher chitinase, protease and phosphatase activities (involved in N and P mobilisation from soil organic matter). A few specialised ectomycorrhizal fungal species are responsible for this adaptation to the long-lasting modification of soil conditions.  相似文献