Soyez le premier à aimer ceci
Imke Thormann, Bioversity International scientist, presented at the international conference Enhanced genepool utilization - Capturing wild relative and landrace diversity for crop improvement, in Cambridge, UK, 16-20 June 2014.
Novel approaches to enhance characterization of plant genetic resources are being developed, as traditional phenotypic characterization techniques have shown to be insufficient to fully harness crop wild relative (CWR) and landrace diversity. These are genomics, transcriptomics, metabolomics, high-throughput phenotyping, as well as less resource intensive predictive characterization techniques. The latter build on the hypothesis that the environment influences gene flow and natural selection, and thus spatial genetic differentiation of organisms. CWR populations growing in a specific environment will possess a suite of adaptive traits shaped by selection pressures unique to these environments. Thus information about a CWR occurrence site can be used to approach the utilization of genetic resources in a more rational way. Two predictive characterization methods for CWR were developed within the PGR Secure project, using an agro-ecological approach for optimizing the search for populations and accessions with targeted adaptive traits: The ecogeographical filtering method combines spatial distribution of the target species with the ecogeographical identification of those environments that are likely to impose selection pressure for the selected trait. Edaphic, geophysic and bioclimatic variables most relevant for adaptation are identified and used together with ecogeographic land characterization maps to identify promising occurrences. The calibration method bases the criteria to filter accessions on existing evaluation data for the trait of interest. Ecogeographical data specific to the environment at collecting sites evaluated for the trait are used as input to identify existing relationships between trait and environment. This relationship is then used to calibrate a model through which other non-evaluated accessions can be assessed. The methods were applied to the four project genera, Avena, Beta, Brassica and Medicago to identify subsets of potentially interesting accessions or occurrences, investigating the following abiotic stress factors: aluminium toxicity for Avena, drought for Beta, drought and salinity for Brassica, and frost for Medicago.
Find out more about our work on crop wild relatives http://www.bioversityinternational.org/research-portfolio/conservation-of-crop-diversity/crop-wild-relatives/