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Submitted to: International Plant Genetic Resources Institute
Publication Type: Research Notes Publication Acceptance Date: 7/1/2004 Publication Date: 8/1/2004 Citation: Richards, C.M. 2004. Molecular technologies for the management and use of gene bank collections. In M.C. de Vicente (ed.) The Evolving Role of Genebanks in the Fast-Developing Field of Molecular Genetics. Issues in Genetic Resources 11:13-18. International Plant Genetic Resources Institute. Rome, Italy. Interpretive Summary: This paper is an editorial on the emerging roles that gene banks will assume as genomic analyses of model plant taxa increase. Several areas of synergy between large scale comparative genomic studies and the phenotypic evaluation and curation of large germplasm collections are emphasized. Technical Abstract: In many respects, the acquisition and maintenance of genetic diversity has been motivated more by the certainty of loss of local landraces and the vulnerability of wild populations in the face of increased habitat loss than from any specific evidence for agricultural worth. Moreover, the cost of storing and maintaining large collections is an investment that seems particularly cost effective compared to the risk of losing these valuable genetic resources (Pardey et al., 2001) While Vavilov's original premise, that the collection of wild relatives is critical for agricultural improvement has greatly influenced the scope of worldwide collecting efforts, the active use of these resources for the development of modern varieties has largely been unsuccessful. The reason may be partly because of the need for pre-breeding lines that serve as a first step in a backcrossing program and partly because the characterization of the germplasm is inadequate. The net result is that most domesticated crop species, pedigrees can be traced to a handful of genetic lineages. Gene banks have an obligation to make their genetic diversity useful and accessible for breeding and research. Large collections are under increasing pressure to become efficient at reducing redundancy, and documenting the variation they contain lest they become relegated to the level of 'seed morgues'. Increasing this assessment has been augmented by the use of molecular markers that quantify the genetic diversity within and between accessions. In general, these techniques rely mostly on the frequencies of neutral markers such as those generated through RAPD, AFLP, SSR or any number of methods that seek to quantify variation at variable loci. This distinctly prospective method is used to cluster the current genetic diversity in a way that facilitates its subsequent use in breeding (Bretting and Widrlechner, 1995; Van Hintum and Van Treuren, 2002). There have been several detailed works that have set out the philosophy behind optimizing collections to assure diverse genetic representation either through the creation of core collections or some form of hierarchical sampling (Brown and Marshall, 1995; Crossa et al., 1994; Hayward and Sackville-Hamilton, 1997). This paper aims to highlight several technical and analytical advances that have enormous potential in effecting the utilization of this diversity for breeding and it identifies several points of synergy between large-scale genomic projects and the management and use of gene banks. |
