Different nontarget-site mechanisms underlie resistance to dicamba and 2,4-D in an Amaranthus tuberculatus population

The objectives of this project were to determine whether the same nontarget-site mechanism confers resistance to dicamba and 2,4-D and to identify genomic regions associated with these resistance traits in an F2 population of Amaranthus tuberculatus. This population originated from a biparental cross between a multiple-herbicide-resistant Amaranthus tuberculatus population (CHR) from Champaign County, Illinois, and an herbicide-sensitive population (WUS) from Brown County, Ohio (GRIN ID: PI 698378). Side shoots of each F2 plant were used for clone propagation, with at least four clones produced from each F2 parent plant and subsequently screened with either dicamba or 2,4-D. Tissues from 188 F2 individuals were collected before plant cloning and herbicide treatment. Two double digest restriction site-associated DNA (ddRAD) libraries were produced and sent to the Roy J. Carver Center at the University of Illinois for sequencing on an Illumina NovaSeq X Plus 10B to generate 100 bp single-reads.