Taxonomic and Life History Bias in Herbicide Resistant Weeds: Implications for Deployment of Resistant Crops

PLoS One. 2013 Sep 9;8(9):e71916. doi: 10.1371/journal.pone.0071916. eCollection 2013.

Abstract

Evolved herbicide resistance (EHR) is an important agronomic problem and consequently a food security problem, as it jeopardizes herbicide effectiveness and increases the difficulty and cost of weed management. EHR in weeds was first reported in 1970 and the number of cases has accelerated dramatically over the last two decades. Despite 40 years of research on EHR, why some weeds evolve resistance and others do not is poorly understood. Here we ask whether weed species that have EHR are different from weeds in general. Comparing taxonomic and life history traits of weeds with EHR to a control group ("the world's worst weeds"), we found weeds with EHR significantly over-represented in certain plant families and having certain life history biases. In particular, resistance is overrepresented in Amaranthaceae, Brassicaceae and Poaceae relative to all weeds, and annuality is ca. 1.5 times as frequent in weeds with EHR as in the control group. Also, for perennial EHR weeds, vegetative reproduction is only 60% as frequent as in the control group. We found the same trends for subsets of weeds with EHR to acetolactate synthase (ALS), photosystem II (PSII), and 5-enolpyruvylshikimate-3-phosphate (EPSP) synthase-inhibitor herbicides and with multiple resistance. As herbicide resistant crops (transgenic or not) are increasingly deployed in developing countries, the problems of EHR could increase in those countries as it has in the USA if the selecting herbicides are heavily applied and appropriate management strategies are not employed. Given our analysis, we make some predictions about additional species that might evolve resistance.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Biological Evolution
  • Crops, Agricultural / drug effects*
  • Crops, Agricultural / genetics
  • Enzyme Inhibitors / pharmacology
  • Herbicide Resistance
  • Herbicides / pharmacology*
  • Magnoliopsida / drug effects
  • Magnoliopsida / genetics
  • Phenotype
  • Phylogeny
  • Plant Proteins / antagonists & inhibitors
  • Plant Proteins / genetics
  • Plant Weeds / drug effects*
  • Plant Weeds / genetics

Substances

  • Enzyme Inhibitors
  • Herbicides
  • Plant Proteins

Grant support

Support for NCE was provided by a John Simon Guggenheim Memorial Fellowship and NSF OPUS grant #DEB-1020799. Support for SRW is supported under grant NSFDGE-0813967. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.