Occurrence of an herbicide‐resistant plant trait in agricultural field margins. Issue 18 (4th September 2015)

• Record Type: Journal Article
• Authors: Gage, Karla L.; Gibson, David J.; Young, Bryan G.; Young, Julie M.; Matthews, Joseph L.; Weller, Stephen C.; Wilson, Robert G.
• Is Part Of: Ecology and evolution. Volume 5:Issue 18(2015:Oct.)
• Page Start: 4161
• Page End: 4173
• Publication Date: 2015-09-04
• Subjects: Ecology -- Periodicals; Evolution -- Periodicals; 577.05
• DOI: 10.1002/ece3.1667
• Languages: English
• ISSNs: 2045-7758

Abstract

<abstract abstract-type="main" id="ece31667-abs-0001"> <title>Abstract</title> <p>Agricultural environments allow study of evolutionary change in plants. An example of evolution within agroecological systems is the selection for resistance to the herbicide glyphosate within the weed, <italic>Conyza canadensis</italic>. Changes in survivorship and reproduction associated with the development of glyphosate resistance (GR) may impact fitness and influence the frequency of occurrence of the GR trait. We hypothesized that site characteristics and history would affect the occurrence of GR <italic>C. canadensis</italic> in field margins. We surveyed GR occurrence in field margins and asked whether there were correlations between GR occurrence and location, crop rotation, GR crop trait rotation, crop type, use of tillage, and the diversity of herbicides used. In a field experiment, we hypothesized that there would be no difference in fitness between GR and glyphosate‐susceptible (GS) plants. We asked whether there were differences in survivorship, phenology, reproduction, and herbivory between 2 GR and 2 GS populations of <italic>C. canadensis</italic> in agrestal and ruderal habitats. We found that geographic location was an important factor in the occurrence of GR <italic>C. canadensis</italic> in field margins. Although not consistently associated with either glyphosate resistance or glyphosate susceptibility, there were differences in phenology, survivorship, and herbivory among biotypes of <italic>C. canadensis</italic>. We found equal or greater fitness in GR biotypes, compared to GS biotypes, and GR plants were present in field margins. Field margins or ruderal habitats may provide refugia for GR <italic>C. canadensis</italic>, allowing reproduction and further selection to occur as seeds recolonize the agrestal habitat. Agricultural practices may select for ecological changes that feed back into the evolution of plants in ruderal habitats.</p> </abstract>