Abstract
It has been claimed that plant breeding reduces genetic diversity in elite germplasm which could seriously jeopardize the continued ability to improve crops. The main objective of this study was to examine the loss of genetic diversity in spring bread wheat during (1) its domestication, (2) the change from traditional landrace cultivars (LCs) to modern breeding varieties, and (3) 50 years of international breeding. We studied 253 CIMMYT or CIMMYT-related modern wheat cultivars, LCs, and Triticum tauschii accessions, the D-genome donor of wheat, with 90 simple sequence repeat (SSR) markers dispersed across the wheat genome. A loss of genetic diversity was observed from T. tauschii to the LCs, and from the LCs to the elite breeding germplasm. Wheat’s genetic diversity was narrowed from 1950 to 1989, but was enhanced from 1990 to 1997. Our results indicate that breeders averted the narrowing of the wheat germplasm base and subsequently increased the genetic diversity through the introgression of novel materials. The LCs and T. tauschii contain numerous unique alleles that were absent in modern spring bread wheat cultivars. Consequently, both the LCs and T. tauschii represent useful sources for broadening the genetic base of elite wheat breeding germplasm.
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Acknowledgements
We thank Bent Skovmand for providing the wheat material for this study. We are also indebted to the Vater & Sohn Eiselen-S.giftung, Ulm, and the German Federal Ministry of Economic Co-operation and Development, for their grateful financial support and collaboration within the project “Efficient management of genetic diversity in wheat: DNA marker for use in wheat breeding programs and gene banks”. We dedicate this article to Dr. Norman Borlaug, the father of the “Green Revolution”.
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Reif, J.C., Zhang, P., Dreisigacker, S. et al. Wheat genetic diversity trends during domestication and breeding. Theor Appl Genet 110, 859–864 (2005). https://doi.org/10.1007/s00122-004-1881-8
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DOI: https://doi.org/10.1007/s00122-004-1881-8