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Article
Population Genetic Diversity in a Maize Reciprocal Recurrent Selection Program
Crop Science
  • Lori L. Hinze, United States Department of Agriculture
  • Stephen Kresovich, Cornell University
  • John D. Nason, Iowa State University
  • Kendall R. Lamkey, Iowa State University
Document Type
Article
Publication Version
Published Version
Publication Date
11-1-2005
DOI
10.2135/cropsci2004.0662
Abstract

The genetic structures of the Iowa Corn Borer Synthetic #1 (CB) and Iowa Stiff Stalk Synthetic (SS) maize (Zea mays L.) populations are important because these populations serve as the model for development of modern commercial hybrids. In 1949, CB and SS were used to start a reciprocal recurrent selection (RRS) breeding program at Iowa State University. This study was conducted to analyze more thoroughly the genetic diversity within this RRS program and illustrate how the RRS program has changed over time at the molecular level. The progress of this program was measured by analyzing the variation at 86 SSR loci among 28 progenitor lines and 30 plants sampled from each of seven cycles (Cycle 0, Cycle 1, Cycle 3, Cycle 6, Cycle 9, Cycle 12, and Cycle 15) in each population. The progenitors of these populations show a high amount of variation on the basis of expected heterozygosity (0.557). As the RRS program proceeded, this variation decreased (Cycle 15, 0.245). In total, a larger amount of genetic variation was found among plants within cycles (66%) than among cycles (13%) or between populations (21%). The repartitioning of variation from within populations (96% in progenitors) to between populations (58% in Cycle 15) over time is consistent with theoretical expectations of divergence between the populations. By sampling intermediate time points, we gained a comprehensive genetic view of CB and SS permitting evaluation of the molecular-level changes occurring as a result of reciprocal recurrent selection.

Comments

This article is from Crop Science 45 (2005): 2435–2442, doi:10.2135/cropsci2004.0662.

Rights
Works produced by employees of the U.S. Government as part of their official duties are not copyrighted within the U.S. The content of this document is not copyrighted.
Language
en
File Format
application/pdf
Citation Information
Lori L. Hinze, Stephen Kresovich, John D. Nason and Kendall R. Lamkey. "Population Genetic Diversity in a Maize Reciprocal Recurrent Selection Program" Crop Science Vol. 45 Iss. 6 (2005) p. 2435 - 2442
Available at: http://works.bepress.com/jason_nason/2/