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41.
Sylvain Poggi Julien Papaïx Claire Lavigne Frédérique Angevin Florence Le Ber Nicolas Parisey Benoît Ricci Fabrice Vinatier Julie Wohlfahrt 《Landscape Ecology》2018,33(10):1679-1690
Context
Agroecosystems produce food and many other services that are crucial for human well-being. Given the scales at which the processes underlying these services take place, agricultural landscapes appear as appropriate spatial units for their evaluation and management. The design of sustainable agricultural landscapes that value these services has thus become a pressing issue but faces major challenges stemming from the diversity of processes, their interactions and the number of scales at stake. Agricultural landscape modelling can provide a key contribution to this design but must still overcome several difficulties to offer reliable tools for decision makers.Objectives
Our study aimed at shedding light on the main scientific and technical difficulties that make the building of landscape models that may efficiently inform decision-makers a complex task, as well as translating them in terms of challenges that can be further investigated and discussed.Methods
We examine current issues and challenges and indicate future research needs to overcome the scientific and technical obstacles in the development of useful agricultural landscape models.Results
We highlight research perspectives to better couple landscape patterns and process models and account for feedbacks, integrate the decisions of multiple stakeholders, consider the spatial and temporal heterogeneity of data and processes, explore alternative landscape organisations and assess multiobjective performance.Conclusion
Coping with the issues and challenges discussed in this paper should improve our understanding of agroecosystems and give rise to new hypotheses, thereby informing future research.42.
Selim S Martin-Laurent F Rouard N Gianinazzi S van Tuinen D 《Pest management science》2007,63(3):269-275
The effect of paenimyxin, a new biopesticide produced by Paenibacillus sp. strain B2, on the density of soil bacterial communities was assessed by colony counting and by 16S rDNA and nirK quantitative polymerase chain reaction (PCR). Paenimyxin had a negative effect on the bacterial colony-forming unit (CFU) number, which was significantly reduced 2 and 4 days after treatment. The effect of paenimyxin on cultivatable bacteria was negligible 7 days after treatment. Approximately 10(7) 16S rDNA sequences per gram of soil (dry weight) were detected by quantitative PCR in all samples. Paenimyxin did not affect the quantification of 16S rDNA or of the denitrifying bacterial community. In addition, RISA fingerprinting showed that the genetic structure of the bacterial communities was significantly modified 2 days after paenimyxin application at 50 microM and 4 days after treatment at lower concentrations (0.5 and 5 microM). The impact of paenimyxin treatment on the genetic structure of soil bacterial communities was transient, as no effect could be observed after 7, 14 and 28 days when compared with the untreated control. 相似文献
43.
Evans Mutegi Fabrice Sagnard Moses Muraya Ben Kanyenji Bernard Rono Caroline Mwongera Charles Marangu Joseph Kamau Heiko Parzies Santie de Villiers Kassa Semagn Pierre Sibiry Traoré Maryke Labuschagne 《Genetic Resources and Crop Evolution》2010,57(2):243-253
The potential gene flow between a crop and its wild relatives is largely determined by the overlaps in their ecological and geographical distributions. Ecogeographical databases are therefore indispensable tools for the sustainable management of genetic resources. In order to expand our knowledge of Sorghum bicolor distribution in Kenya, we conducted in situ collections of wild, weedy and cultivated sorghum. Qualitative and quantitative morphological traits were measured for each sampled wild sorghum plant. Farmers’ knowledge relating to the management of sorghum varieties and autecology of wild sorghum was also obtained. Cluster analysis supports the existence of several wild sorghum morphotypes that might correspond to at least three of the five ecotypes recognized in Africa. Intermediate forms between wild and cultivated sorghum belonging to the S. bicolor ssp. drummondii are frequently found in predominantly sorghum growing areas. Crop-wild gene flow in sorghum is likely to occur in many agroecosystems of Kenya. 相似文献
44.
Stéphane Pesce Fabrice Martin-Laurent Nadine Rouard Agnès Robin Bernard Montuelle 《Journal of Soils and Sediments》2010,10(4):698-707
Purpose
Surface runoff and erosion are major drivers of pesticide transport from soils to rivers draining vineyard watersheds. A recent study showed that applications of diuron on vineyards and diuron dispersal could lead to microbial adaptation to diuron biodegradation from treated soils to the receiving hydrosystem. Given the limited knowledge on microbial adaptation to pesticide degradation in aquatic environments, we conducted a microcosm study designed to assess the impact of runoff and erosion processes on the adaptation of riverine-sediment microbial communities to diuron mineralization. 相似文献45.
Calvayrac C Martin-Laurent F Faveaux A Picault N Panaud O Coste CM Chaabane H Cooper JF 《Pest management science》2012,68(3):340-347
BACKGROUND: The dissipation kinetics of the herbicide sulcotrione sprayed 4 times on a French soil was studied using a laboratory microcosm approach. An advanced cultivation‐based method was then used to isolate the bacteria responsible for biotransformation of sulcotrione. Chromatographic methods were employed as complementary tools to define its metabolic pathway. RESULTS: Soil microflora was able quickly to biotransform the herbicide (DT50 ≈ 8 days). 2‐Chloro‐4‐mesylbenzoic acid, one of its main metabolites, was clearly detected. However, no accelerated biodegradation process was observed. Eight pure sulcotrione‐resistant strains were isolated, but only one (1OP) was capable of degrading this herbicide with a relatively high efficiency and to use it as a sole source of carbon and energy. In parallel, another sulcotrione‐resistant strain (1TRANS) was shown to be incapable of degrading the herbicide. Amplified ribosomal restriction analysis (ARDRA) and repetitive extragenic palendromic PCR genomic (REP‐PCR) fingerprinting of strains 1OP and 1TRANS gave indistinguishable profiles. CONCLUSION: Sequencing and aligning analysis of 16S rDNA genes of each pure strain revealed identical sequences and a close phylogenetic relationship (99% sequence identity) to Pseudomonas putida. Such physiological and genetic properties of 1OP to metabolise sulcotrione were probably governed by mobile genetic elements in the genome of the bacteria. Copyright © 2011 Society of Chemical Industry 相似文献
46.
Hancock AM Brachi B Faure N Horton MW Jarymowycz LB Sperone FG Toomajian C Roux F Bergelson J 《Science (New York, N.Y.)》2011,334(6052):83-86
Understanding the genetic bases and modes of adaptation to current climatic conditions is essential to accurately predict responses to future environmental change. We conducted a genome-wide scan to identify climate-adaptive genetic loci and pathways in the plant Arabidopsis thaliana. Amino acid-changing variants were significantly enriched among the loci strongly correlated with climate, suggesting that our scan effectively detects adaptive alleles. Moreover, from our results, we successfully predicted relative fitness among a set of geographically diverse A. thaliana accessions when grown together in a common environment. Our results provide a set of candidates for dissecting the molecular bases of climate adaptations, as well as insights about the prevalence of selective sweeps, which has implications for predicting the rate of adaptation. 相似文献
47.
Claude E. Boyd Louis R. D'Abramo Brent D. Glencross David C. Huyben Lorenzo M. Juarez George S. Lockwood Aaron A. McNevin Albert G. J. Tacon Fabrice Teletchea Joseph R. Tomasso Jr Craig S. Tucker Wagner C. Valenti 《Journal of the World Aquaculture Society》2020,51(3):578-633
Important operational changes that have gradually been assimilated and new approaches that are developing as part of the movement toward sustainable intensive aquaculture production systems are presented via historical, current, and future perspectives. Improved environmental and economic sustainability based on increased efficiency of production continues to be realized. As a result, aquaculture continues to reduce its carbon footprint through reduced greenhouse gas emissions. Reduced use of freshwater and land resources per unit of production, improved feed management practices as well as increased knowledge of nutrient requirements, effective feed ingredients and additives, domestication of species, and new farming practices are now being applied or evaluated. Successful expansion into culture of marine species, both off and on shore, offers the potential of substantial increases in sustainable intensive aquaculture production combined with integrative efforts to increase efficiency will principally contribute to satisfying the increasing global demand for protein and food security needs. 相似文献
48.
Dominance of a resistance trait can be defined as a measure of the relative position of the phenotype of the heterozygote RS compared with the phenotype of the two corresponding homozygotes, SS and RR. This parameter has been shown to have primary importance in the dynamics of pesticide resistance evolution. Literature on insecticide resistance suggests that dominance levels in the presence of insecticide vary greatly from completely recessive to completely dominant. With insecticides, both the chemical applied and the dosages used have been demonstrated to affect the dominance. By contrast, almost all herbicide resistances have been found to be inherited as partially to totally dominant traits. This discrepancy between weeds and insects may partly result from the methodologies applied to measure the dominance, ie a single dose for herbicide versus several doses for insecticide. Using two well-known resistances (csr1-1 and csr1-2) to acetolactate synthase (ALS) inhibitors in Arabidopsis thaliana (L) Heynh (mouse-ear cress), we used several herbicide doses to determine the dominance level to six ALS-inhibiting herbicides. The dominance level in the presence of herbicide varied from completely dominant to completely recessive, depending on the resistance allele and the herbicide tested. The dominance of the csr1-1 and csr1-2 resistance alleles ranged from 0 (completely recessive) to 1.1 (dominant) and from 0 to 0.3 (partially dominant), respectively. The recessivity of some resistance alleles in the presence of herbicide could lead to the development of improved resistance management in order to delay or avoid herbicide resistance evolution, especially in the control of outcrossing weed species. 相似文献
49.
50.
Michaël Aubert Mickaël Hedde Thibaud Decaëns Fabrice Bureau Pierre Margerie Didier Alard 《Pedobiologia》2003,47(5-6):904-912