Testing the link between genome size and growth rate in maize
- Published
- Accepted
- Subject Areas
- Evolutionary Studies, Plant Science
- Keywords
- adaptation, leaf elongation rate, Zea mays, DNA content, breeding
- Copyright
- © 2016 Tenaillon et al.
- Licence
- This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, reproduction and adaptation in any medium and for any purpose provided that it is properly attributed. For attribution, the original author(s), title, publication source (PeerJ Preprints) and either DOI or URL of the article must be cited.
- Cite this article
- 2016. Testing the link between genome size and growth rate in maize. PeerJ Preprints 4:e2333v1 https://doi.org/10.7287/peerj.preprints.2333v1
Abstract
Little is known about the factors driving within species Genome Size (GS) variation. GS may be shaped indirectly by natural selection on development and adaptative traits. Because GS variation is particularly pronounced in maize, we have sampled 83 maize inbred lines from three well described genetic groups adapted to contrasted climate conditions: inbreds of tropical origin , Flint inbreds grown in temperate climates, and Dent inbreds distributed in the Corn Belt. As a proxy for growth rate, we measured the Leaf Elongation Rate maximum during nighttime (LERmax) as well as GS in all inbred lines. In addition we combined available and new nucleotide polymorphism data at 29,090 sites to characterize the genetic structure of our panel. We found significant variation for both LERmax and GS among groups defined by our genetic structuring. Tropicals displayed larger GS than Flints while Dents exhibited intermediate values. LERmax followed the opposite trend with greater growth rate in Flints than in Tropicals. In other words, LERmax and GS exhibited a significantly negative correlation (r=-0.27). However, this correlation was driven by among-group variation rather than within-group variation – it was no longer significant after controlling for structure and kinship among inbreds. Our results indicate that selection on GS may have accompanied ancient maize diffusion from its center of origin, with large DNA content excluded from temperate areas. Whether GS has been targeted by more intense selection during modern breeding within groups remains an open question. <!--[if !supportLineBreakNewLine]--> <!--[endif]-->
Author Comment
This is a submission to PeerJ for review.