Directional selection for flowering time leads to adaptive evolution in Raphanus raphanistrum (Wild radish)

MICHAEL B. ASHWORTH; MICHAEL J. WALSH; KEN C. FLOWER; MARTIN VILA AIUB; STEPHEN B POWLES

EVOLUTIONARY APPLICATIONS

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2016

1752-4571

Herbicideshave been the primary tool for controlling large populations of yield depletingweeds from agro-ecosystems, resulting in the evolution of widespread herbicideresistance. In response, non-herbicidal techniques have been developed whichintercept weed seeds at harvest before they enter the soil seedbank. Howeverthe efficiency of these techniques apply an intense selection for any traitthat enable weeds to evade collection, with early flowering ecotypes consideredlikely to result in early seed shedding. Using a field collected wild radish population,five recurrent generations were selected for early maturity and threegenerations for late maturity. Phenology associated with flowering time andgrowth traits were measured. Our results demonstrate the adaptive capacity of wildradish to halve its time to flowering following five generations of earlyflowering selection. Early maturing phenotypes had reduced height andbiomass at maturity, leading to less competitive, more prostrate growth forms. Followingthree generations of late flowering selection, wild radish doubled its time to floweringtime leading to increased biomass and flowering height at maturity. This studydemonstrates the potential for the rapid evolution in growth traits in responseto highly effective seed collection techniques that imposed a selection on weedpopulations within agro-ecosystems at harvest.