Pollen-Mediated Gene Flow and Transfer of Herbicide-Resistant Alleles

2019 Nebraska Crop Management Conference Proceedings

Pollen-Mediated Gene Flow and Transfer of Herbicide-Resistant Alleles

Managing glyphosate-resistant weeds is a challenge for growers in the north-central United States. Weeds typically become resistant to herbicide(s) when the same herbicide is used repeatedly for several years in the same field or due to mutation.

  • Once herbicide-resistant weeds evolve, they can be spread by pollen and/or seed movement, known as pollen- and seed-mediated gene flow, respectively.
  • Gene flow via vegetative propagule has rarely been addressed, but could be an important avenue for certain weed species.
  • Reproductive biology differs markedly among weed species, as does the potential for gene flow.
  • Pollen-mediated gene flow at a distance could allow the spread of rare herbicide-resistant alleles and favor the evolution of multiple herbicide-resistant biotypes through the accumulation of different resistant genes in an individual weed or weed population.
  • The speaker will discuss examples of common waterhemp, Palmer amaranth, and giant ragweed to demonstrate the role of gene flow in transfer of herbicide-resistant alleles. For more information about speaker’s research program see https://agronomy.unl.edu/jhala.

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