Ahmed Amri, Abdallah Bari, Michael Baum
International Center for Agricultural Research in the Dry Areas (ICARDA), Tunis, Tunisia
The continuum of collecting, conserving and using genetic resources are key to sustain genetic gains to respond to the needs of the growing populations and to overcome the challenges posed by the major abiotic and biotic stresses. ICARDA genebank conserved more than 141,000 accessions of cereals, food legumes, forages and range species, mainly landraces and wild relatives One of the FIGS approach methodologies uses both trait and climate data to develop a priori information or specialized knowledge as per Gollin et al. (2000) based on the quantification of the trait-environment relationship (Street et al. …Mackay and Street. 2004, Endersn et al 2011……). The a priori information is used in turn to define a subset of accessions with a high probability of containing the sought after traits. Quantitative relationships between traits and climate parameters have been established and suggested as basis for selecting FIGS subsets as well as for modeling the impact of climate changes (Barboni et al. 2004) Effective approaches are needed to better target the genebank accessions conserved in the genebank or managed in situ in the natural habitats.
Gap analysis, combined with GIS abiotic and biotic stress layers can be used to guide future collecting missions to add novel diversity and accessions with potential genes for sought traits. ICARDA has used this approach to collect landraces and wild relatives of cereals and legumes with potential tolerance to salt, heat and drought. Focused Identification of Germplasm Strategy (FIGS) uses both trait and climate data to develop a priori information or specialized knowledge and based on the quantification of the trait-environment relationship a manageable subset with higher frequency of finding sought trait is developed for evaluation. This approach has shown its effectiveness in finding novel genes for major pests and diseases in cereals (New sources of resistance to Russian wheat aphid, Sunn pest, Powdery mildew, etc.) and food legumes (leaf minor, aschocyta blight,etc) and sources of tolerance to drought and salt.
Precision phenotypic evaluation and genotypic characterization (EcoTilling) are important steps to select the best parental germplasm to use as sources for sought traits. The use of wild relatives for various crops genepools (pre-breeding) is an important activity to tackle complex traits and should be given more importance in the future.
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