Winter Wheat in England and Wales, 1923-1995 : What do Indices of Genetic Diversity Reveal?

Srinivasan, C. S. and Thirtle, Colin and Palladino, Paolo (2003) Winter Wheat in England and Wales, 1923-1995 : What do Indices of Genetic Diversity Reveal? Plant Genetic Resources, 1 (1). pp. 43-57. ISSN 1479-2621

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Abstract

Genealogical data have been used very widely to construct indices with which to examine the contribution of plant breeding programmes to the maintenance and enhancement of genetic resources. In this paper we use such indices to examine changes in the genetic diversity of the winter wheat crop in England and Wales between 1923 and 1995. We find that, except for one period characterized by the dominance of imported varieties, the genetic diversity of the winter wheat crop has been remarkably stable. This agrees with many studies of plant breeding programmes elsewhere. However, underlying the stability of the winter wheat crop is accelerating varietal turnover without any significant diversification of the genetic resources used. Moreover, the changes we observe are more directly attributable to changes in the varietal shares of the area under winter wheat than to the genealogical relationship between the varieties sown. We argue, therefore, that while genealogical indices reflect how well plant breeders have retained and exploited the resources with which they started, these indices suffer from a critical limitation. They do not reflect the proportion of the available range of genetic resources which has been effectively utilized in the breeding programme: complex crosses of a given set of varieties can yield high indices, and yet disguise the loss (or non-utilization) of a large proportion of the available genetic diversity.

Item Type:
Journal Article
Journal or Publication Title:
Plant Genetic Resources
Additional Information:
http://journals.cambridge.org/action/displayJournal?jid=UHY The final, definitive version of this article has been published in the Journal, Plant Genetic Resources, 1 (1), pp 43-57 2003, © 2003 Cambridge University Press.
Uncontrolled Keywords:
/dk/atira/pure/subjectarea/asjc/1100/1110
Subjects:
?? coefficient of parentagegenetic diversityplant breedingplant sciencegeneticsagronomy and crop scienceda great britain ??
ID Code:
20901
Deposited By:
Deposited On:
03 Dec 2008 15:05
Refereed?:
Yes
Published?:
Published
Last Modified:
27 Nov 2024 01:22