Work

Glyphosate resistance and EPSPS gene amplification confirmed in a waterhemp (Amaranthus tuberculatus) biotype from Connecticut

Year: 2025

Type: article

Abstract: Waterhemp (Amaranthus tuberculatus) is an economically important broadleaf weed that threatens corn and soybean production across the United States. A waterhemp biotype (CT_Res [resistant biotype from Connecticut]) surviving multiple glyphosate applications was identified from a corn field in Connecticut (CT). Greenhouse and laboratory studies were conducted to (1) confirm glyphosate resistance in CT_Res waterhemp biotype and (2) investigate if the glyphosate resistance in CT_Res biotype is due to target‐site‐based mechanism. Dose‐response studies indicated that CT_Res biotype was 5.8‐fold more resistant to glyphosate compared to a known susceptible biotype (NE_Sus) from Nebraska. No point mutation was detected at Pro102 or Thr106 positions in the EPSPS gene of the CT_Res biotype. The quantitative polymerase chain reaction assays revealed that one of the three CT_Res waterhemp plants had 3.5‐fold higher EPSPS gene copy number (relative to the housekeeping CPS gene), whereas the other two plants did not reveal EPSPS gene amplification. Obviously, the EPSPS gene amplification partially explains glyphosate resistance in newly identified glyphosate‐resistant waterhemp biotype from CT, indicating that alternative mechanisms might exist. This research reports the first case of glyphosate resistance and EPSPS gene amplification in waterhemp from Connecticut and highlights the need for adoption of diversified weed control strategies to prevent its further spread.

Source: Agrosystems Geosciences & Environment

DOI: 10.1002/agg2.70120

Authors: Jatinder S. Aulakh, Vipan Kumar, Nathaniel Westrick, Andrew J. Price, Amit J. Jhala

Institutions: Connecticut Agricultural Experiment Station, Cornell University, New York State College of Agriculture & Life Sciences, Agricultural Research Service, University of Nebraska–Lincoln

Language: English

Topic: Weed Control and Herbicide Applications

Subfield: Plant Science

Field: Agricultural and Biological Sciences

Domain: Life Sciences

SDG: Zero hunger

Open Access status: gold

Estimated APC paid: $2,040