Optimal sampling strategies for core collections of plant genetic resources
A core collection of crop germplasm aims to represent the genetic diversity in a single collection or in a crop species with minimum similarity between its entries. Core collections have a major role to play in conserving genetic resources and using them in plant improvement. Core selection can be based on stratified sampling from groups of related accessions. Elementary neutral theory indicates that the relative number from each group should be proportional to its level of polymorphism. This procedure has some biases when alleles are finite in number, or heterotic, or deleterious. However, in general, the weighting strategy is in practice robust to these departures from the assumptions underlying theory. Variation in divergence among populations is a factor that merits attention. In general, weighting in conservation should include both elements of richness and degree of divergence.
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- Brown, A. H. D. (1989a) The case for core collections. In: Brown, A. H. D., Frankel, O. H., Marshall, D. R. and Williams, J. T. (eds), The use of plant genetic resources. Cambridge University Press, Cambridge, pp. 136–156.Google Scholar
- Brown, A. H. D. (1993) The core collection at the crossroads. In: Hodgkin, T., Brown, A. H. D., van Hintum, T. J. L. and Morales, E. A. V. (eds), Core collections of plant genetic resources. John Wiley and Sons Ltd., Chichester.Google Scholar
- Brown, A. H. D. and Briggs, J. D. (1991) Sampling strategies for genetic variation in ex situ collections of endangered plant species. In: Falk, D. A. and Holsinger K. E. (eds), Genetics and conservation of rare plants. Oxford University Press, Oxford, pp. 99–119.Google Scholar
- Frankel, O. H. (1984) Genetic perspectives of germplasm conservation. In: Arber, W., Llimensee, K., Peacock, W. J. and Starlinger, P. (eds), Genetic manipulation: Impact on man and society. Cambridge University Press, Cambridge, pp. 161–170.Google Scholar
- Frankel, O. H. and Brown, A. H. D. (1984) Plant genetic resources today: a critical appraisal. In: Holden, J. H. W. and Williams, J. T. (eds), Crop genetic resources: Conservation and evaluation. George Allen & Unwin Ltd., London, pp. 249–257.Google Scholar
- Frankel, O. H. and Soulé, M. E. (1981) Conservation and Evolution. Cambridge University Press, Cambridge.Google Scholar
- Holden, J. H. W. (1984) The second ten years. In: Holden, J. H. W. and Williams, J. T. (eds), Crop genetic resources: Conservation and evaluation. George Allen & Unwin Ltd., London, pp. 277–285.Google Scholar
- MacArthur, R. H. and Wilson, E. O. (1967) The theory of island biogeography. Princeton University Press, Princeton, N.J.Google Scholar
- Marshall, D. R. and Brown, A. H. D. (1975) Optimum sampling strategies in genetic conservation. In: Frankel, O. H. and Hawkes, J. G. (eds), Crop genetic resources for today and tomorrow. Cambridge University Press, Cambridge, pp. 53–80.Google Scholar
- Nevo, E., Zohary, D., Brown, A. H. D. and Haber, M. (1979) Genetic diversity and environmental asociations of wild barley, Hordeum spontaneum , in Israel. Evolution 33: 815–833.Google Scholar
- Plucknett, D. L., Smith, N. J. H., Williams, J. T. and Murthi Anishetty, N. (1987) Gene banks and the world’s food. Princeton University Press, Princeton, N.J.Google Scholar
- Wilson, E. O. (1988) Biodiversity. National Academic Press, Washington DC.Google Scholar