Expoloring the Intensity and Consequences ofPhenological Assortative Mating in Plant Populations.

University Of California-Irvine, Irvine CA

Investigators

Abstract

It has been long supposed that variation in flowering time induces assortative mating in plants: Early bloomers mate predominantly with other early plants, while late bloomers tend to mate with other late plants. Theory predicts that when 'like mates with like,' the offspring generation contains more individuals with extreme gene combinations, compared to random mating. This can facilitate plant response to selection on the assorting trait. But assortment may also increase the genetic covariance between the assorting trait and other traits. If so, selection on the assorting trait can be either accelerated or decelerated, depending on the direction of selection on the correlated trait. This will be the first comprehensive study of assortative mating and its impacts on plant genetic variation. Field and greenhouse experiments will provide reinforcing information on the ways that mating patterns can modulate the response to selection. The proposed work will enhance standard breeding methods for plant improvement. It also has applications in bio-safety analysis for genetically engineered crops. Understanding the contribution of flowering time to crop-weed hybridization rates is a key factor in determining whether particular crop varieties will be unsafe in areas where the modified gene can potentially 'escape' from cultivation and into weed species.