title: Reproductive isolation during domestication.
abstract: It has been hypothesized that reproductive isolation should facilitate evolution under domestication. However, a systematic comparison of reproductive barrier strength between crops and their progenitors has not been conducted to test this hypothesis. Here, we present a systematic survey of reproductive barriers between 32 economically important crop species and their progenitors to better understand the role of reproductive isolation during the domestication process. We took a conservative approach, avoiding those types of reproductive isolation that are poorly known for these taxa (e.g., differences in flowering time). We show that the majority of crops surveyed are isolated from their progenitors by one or more reproductive barriers, despite the fact that the most important reproductive barrier in natural systems, geographical isolation, was absent, at least in the initial stages of domestication for most species. Thus, barriers to reproduction between crops and wild relatives are closely associated with domestication and may facilitate it, thereby raising the question whether reproductive isolation could be viewed as a long-overlooked "domestication trait." Some of the reproductive barriers observed (e.g., polyploidy and uniparental reproduction), however, may have been favored for reasons other than, or in addition to, their effects on gene flow.
authors: Department of Botany and Biodiversity Research Centre, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada.
authors: Hannes
authors: H
authors: Dempewolf
authors: Kathryn A
authors: KA
authors: Hodgins
authors: Sonja E
authors: SE
authors: Rummell
authors: Norman C
authors: NC
authors: Ellstrand
authors: Loren H
authors: LH
authors: Rieseberg
mesh_terms: D018556:Crops, Agricultural / Q000235:genetics* / Q000502:physiology; D051456:Gene Flow; D019684:Magnoliopsida / Q000235:genetics / Q000502:physiology; D008957:Models, Genetic; D012098:Reproduction; D060047:Reproductive Isolation; D013045:Species Specificity