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Genetic erosion in crops: concept, research results and challenges

Published online by Cambridge University Press:  19 October 2009

Mark van de Wouw ,
Chris Kik ,
Theo van Hintum ,
Rob van Treuren  and
Bert Visser
Mark van de Wouw*
Affiliation:
Centre for Genetic Resources, The Netherlands (CGN), Wageningen University and Research Centre, Wageningen, The Netherlands
Chris Kik
Affiliation:
Centre for Genetic Resources, The Netherlands (CGN), Wageningen University and Research Centre, Wageningen, The Netherlands
Theo van Hintum
Affiliation:
Centre for Genetic Resources, The Netherlands (CGN), Wageningen University and Research Centre, Wageningen, The Netherlands
Rob van Treuren
Affiliation:
Centre for Genetic Resources, The Netherlands (CGN), Wageningen University and Research Centre, Wageningen, The Netherlands
Bert Visser
Affiliation:
Centre for Genetic Resources, The Netherlands (CGN), Wageningen University and Research Centre, Wageningen, The Netherlands
*
*Corresponding author. E-mail: markvandewouw@yahoo.co.uk
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Abstract

The loss of variation in crops due to the modernization of agriculture has been described as genetic erosion. The current paper discusses the different views that exist on the concept of genetic erosion in crops. Genetic erosion of cultivated diversity is reflected in a modernization bottleneck in the diversity levels that occurred during the history of the crop. Two stages in this bottleneck are recognized: the initial replacement of landraces by modern cultivars; and further trends in diversity as a consequence of modern breeding practices. Genetic erosion may occur at three levels of integration: crop, variety and allele. The different approaches in the recent literature to measure genetic erosion in crops are reviewed. Genetic erosion as reflected in a reduction of allelic evenness and richness appears to be the most useful definition, but has to be viewed in conjunction with events at variety level. According to the reviewed literature, the most likely scenario of diversity trends during modernization is the following: a reduction in diversity due to the replacement of landraces by modern cultivars, but no further reduction after this replacement has been completed.

Keywords

genetic erosioncrop diversitymodernization bottleneck
Type
Research Article
Information
Plant Genetic Resources , Volume 8 , Issue 1 , April 2010 , pp. 1 - 15
Copyright
Copyright © NIAB 2009

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