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Stéphanie Mariette Emilie Balsemin Solenn Stoeckel Muriel Tavaud Hervé Le Bouler Frédérique Santi Michel Verger 《Annals of Forest Science》2007,64(5):533-539
Parents and progenies genetic diversity, and male and female contributions to the seed crop were assessed in three experimental Prunus avium seed orchards. Collected data were used to compare different effective population sizes, based on phenological, seed crop and paternity analysis. Our results did not show any difference of genetic diversity between parents and progenies. A limited pollen pollution was detected. We showed that distance and coflowering among clones had a significant effect on effective pollination, and a significant effect of the production of flowers was revealed in one of the seed orchards. Our study also revealed a quite low number of effective size of fathers per mother, but high effective sizes of mothers, fathers and parents at the level of the seed orchard. Finally, the calculation of effective size of mothers, fathers and parents was not highly modified when having the complete information based on the paternity analysis. 相似文献
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Yucheng Feng Donald M. Stoeckel Edzard van Santen Robert H. Walker 《Biology and Fertility of Soils》2002,36(6):456-460
The sensitivity of creeping bentgrass (Agrostis palustris Huds.) to the extreme heat found in the southeastern United States has led to the development of new greens-management methods. The purpose of this study was to examine the effects of subsurface aeration and growth regulator applications on soil microbial communities and mycorrhizal colonization rates in a creeping bentgrass putting green. Two cultivars (Crenshaw and Penncross), a growth regulator (trinexapac-ethyl), and subsurface aeration were evaluated in cool and warm seasons. Total bacterial counts were higher in whole (unsieved) soils than in sieved soils, indicating a richer rhizosphere soil environment. Mycorrhizal infection rates were higher in trinexapac-ethyl (TE) treated plants. High levels of hyphal colonization and relatively low arbuscule and vesicle occurrence were observed. Principal components analysis of whole-soil fatty acid methyl ester (FAME) profiles indicated that warm-season microbial populations in whole and sieved soils had similar constituents, but the populations differed in the cool season. FAME profiles did not indicate that subsurface aeration and TE application affected soil microbial community structure. This is the first reported study investigating the influences of subsurface aeration and TE application on soil microorganisms in a turfgrass putting green soil. 相似文献
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Tonya A. Lander Etienne K. Klein Solenn Stoeckel Stéphanie Mariette Brigitte Musch Sylvie Oddou-Muratorio 《Landscape Ecology》2013,28(9):1769-1783
Widespread ecosystem change has led to declines in species world-wide. The loss of pollinators in particular constitutes a problem for ecosystem function and crop production. Understanding how landscape change affects pollinator movement, effective pollen flow, and plant and pollinator survival is therefore a global priority. In this study we investigated patterns of effective pollen flow, using wild cherry tree (Prunus avium) progeny arrays, to address two questions in three case studies: Do land-use types present different resistances to pollinator movement? Which pollinator travel path best explains the pollination data (straight lines, weighted straight lines, least cost paths or pair-wise resistance)? Trees and progeny arrays were genotyped and effective pollen flow and pollinator movement were estimated using the spatially explicit mating model. We found that pollinators did modify their travel paths in response to land-use type and arrangement, but the travel path that best described pollinator movement and the resistance rank of the land uses depended on the type and size of land-use patches and the landscape context. We propose a novel theoretical framework rooted in behavioural ecology, the resource model, for interpreting pollinator behaviour in heterogeneous landscapes. We conclude by discussing the importance and practicality of conservation and management strategies in which native and non-native land-use types together provide functional habitat and support ecosystem services across economic landscapes. 相似文献
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Katja Stoeckel Leif H?jvang Nielsen Herbert Fuhrmann Lisa Bachmann 《Acta veterinaria Scandinavica》2011,53(1):57
Background
In dogs, increasing the tissue n-3 fatty acid (FA) content is associated with potential benefit in some medical conditions, e.g. atopic dermatitis, cancer or heart disease. Therefore effectively and conveniently increasing tissue n-3 FA levels in dogs is of interest. Incorporation of dietary n-3 FA into cell membranes may be studied by FA analysis of erythrocyte membranes (EM), because of the correlation of its FA composition with the FA composition of other cells. Aim of the study was to determine whether an n-3 FA additive added to a control diet is as effective in increasing EM n-3 FA content as feeding an n-3 FA enriched diet. Furthermore the time course of the incorporation of dietary n-3 FA into canine EM was investigated.Methods
Thirty dogs were randomly divided into three dietary groups with ten dogs per group. CONT got a dry dog food diet which did not contain EPA or DHA. FO got a dry dog food diet with a high EPA and DHA content. ADD got the CONT diet combined with an n-3 FA additive rich in DHA and EPA. After a feeding period of 12 weeks the additive was discontinued in ADD and these dogs were fed CONT diet for another four weeks to observe washout effects. Erythrocyte lipids were extracted from venous blood samples and their FA composition was determined by gas chromatography. The Mann-Whitney-U-test was used to detect significant differences between the different groups and time points.Results
After one week the proportions of n-3 FA, DHA and EPA were already significantly increased in ADD and FO, apparently reaching a plateau within eight weeks. In our study DHA and not EPA was preferably incorporated into the EM. After discontinuing the administration of the additive in ADD, the n-3 FA values declined slowly without reaching baseline levels within four weeks.Conclusions
In dogs, an increase of dietary n-3 FA content leads to a rapid inclusion of n-3 FA into EM, regardless of whether the n-3 FA are offered as an enriched diet or as a normal diet supplemented with an n-3 FA additive. 相似文献5.
K. Stoeckel L. Bachmann G. Dobeleit H. Fuhrmann 《Journal of animal physiology and animal nutrition》2013,97(6):1142-1151
An elevated level of long‐chain n‐3 fatty acids (FA) in tissue membranes has a positive influence on the progression and treatment of many diseases. Therefore, dietary supplementation of n‐3 FA is recommended in some diseases. Even though n‐3 FA are absorbed readily from the diet, their incorporation into tissues may be compromised in diseased animals. In a clinical setting, it is desirable to monitor the success of dietary intervention. Plasma FA as well as erythrocyte membrane (EM) FA can be used to monitor dietary FA intake. This study compares FA from EM and plasma with regard to their reaction time and reliability for monitoring dietary changes of tissue FA profiles in dogs. Thirty dogs were divided into three groups and fed for 12 weeks. The control group (CONT) was fed a commercial standard diet low in n‐3 FA. One group received the standard diet and 85 mg/kg body weight of a docosahexaenoic acid (DHA) concentrate (ADD). The third group was fed a commercial dog food containing fish oil (FO), which is rich in eicosapentaenoic acid (EPA). EM and plasma FA profiles were analysed by GC separately. Data on EM FA were published recently. n‐3 FA in plasma reached the new level after 2 weeks (8 weeks in EM). Dietary differences between DHA and EPA are obvious after 1 week already. The concomitant decrease in plasma n‐6 FA differed between ADD and FO. In general, the correlation of n‐6 FA between plasma and EM was low. We therefore conclude that analysis of plasma FA is sufficient for monitoring a diet‐induced increase in tissue n‐3 FA in dogs. However, EM FA should be analysed if the effect of dietary intervention on tissue n‐6 FA is important. 相似文献
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