TY - JOUR
T1 - Different nontarget-site mechanisms underlie resistance to dicamba and 2,4-D in an Amaranthus tuberculatus population
AU - Werle, Isabel Schlegel
AU - Bobadilla, Lucas Kopecky
AU - Raiyemo, Damilola A.
AU - Lopez, Alexander J.
AU - Mesquita Machado, Filipi
AU - Tranel, Patrick J.
N1 - This work was partially supported by the USDA National Institute of Food and Agriculture (grant no. 2020\u201067013\u201031854 and Hatch accession no. 7000961).
PY - 2025/2/18
Y1 - 2025/2/18
N2 - BACKGROUND: Amaranthus tuberculatus (Moq.) Sauer (waterhemp) has emerged as one of several weed species that is resistant to synthetic auxin herbicides (SAHs). Among the mechanisms of resistance to SAHs, nontarget-site resistance (NTSR) has been of particular concern owing to its complexity. Here, we integrated linkage mapping with transcriptome analysis to explore NTSR mechanisms to two SAHs, dicamba and 2,4-D, in a multiple-herbicide-resistant A. tuberculatus population (CHR). RESULTS: Phenotypic evaluations of an F2 mapping population indicated a polygenic basis for both dicamba and 2,4-D resistance in CHR. A weak correlation was observed between phenotypic responses to dicamba and 2,4-D treatments. Linkage mapping analyses revealed eight quantitative trait loci (QTL) regions associated with dicamba and 2,4-D resistance mapped to seven A. tuberculatus chromosomes. Together, these QTL regions explained 24.2 and 23.1% of the variation in dicamba- and 2,4-D-resistant phenotypes, respectively. Only one co-localized QTL region was found between the two resistance traits. CONCLUSION: The results of this study demonstrated that resistance to dicamba and 2,4-D in the CHR population is under the control of genes at multiple loci. The weak phenotypic and genetic associations of resistance traits indicate that more than one NTSR mechanism confers resistance to dicamba and 2,4-D in this A. tuberculatus population.
AB - BACKGROUND: Amaranthus tuberculatus (Moq.) Sauer (waterhemp) has emerged as one of several weed species that is resistant to synthetic auxin herbicides (SAHs). Among the mechanisms of resistance to SAHs, nontarget-site resistance (NTSR) has been of particular concern owing to its complexity. Here, we integrated linkage mapping with transcriptome analysis to explore NTSR mechanisms to two SAHs, dicamba and 2,4-D, in a multiple-herbicide-resistant A. tuberculatus population (CHR). RESULTS: Phenotypic evaluations of an F2 mapping population indicated a polygenic basis for both dicamba and 2,4-D resistance in CHR. A weak correlation was observed between phenotypic responses to dicamba and 2,4-D treatments. Linkage mapping analyses revealed eight quantitative trait loci (QTL) regions associated with dicamba and 2,4-D resistance mapped to seven A. tuberculatus chromosomes. Together, these QTL regions explained 24.2 and 23.1% of the variation in dicamba- and 2,4-D-resistant phenotypes, respectively. Only one co-localized QTL region was found between the two resistance traits. CONCLUSION: The results of this study demonstrated that resistance to dicamba and 2,4-D in the CHR population is under the control of genes at multiple loci. The weak phenotypic and genetic associations of resistance traits indicate that more than one NTSR mechanism confers resistance to dicamba and 2,4-D in this A. tuberculatus population.
KW - Amaranthus tuberculatus
KW - genetic mapping
KW - nontarget-site herbicide resistance
KW - quantitative trait loci
KW - synthetic auxin herbicides
UR - https://www.scopus.com/pages/publications/85219740679
UR - https://www.scopus.com/pages/publications/85219740679#tab=citedBy
U2 - 10.1002/ps.8712
DO - 10.1002/ps.8712
M3 - Article
C2 - 39966088
AN - SCOPUS:85219740679
SN - 1526-498X
VL - 81
SP - 3464
EP - 3473
JO - Pest Management Science
JF - Pest Management Science
IS - 7
ER -