Characterization and inheritance of dicamba resistance in a multiple-resistant waterhemp (Amaranthus tuberculatus) population from Illinois

Abstract

Waterhemp (Amaranthus tuberculatus (Moq.) Sauer) is one of the most troublesome agronomic weeds in the midwestern US. The rapid evolution and selection of herbicide-resistance traits in A. tuberculatus is a major challenge in managing this species. An A. tuberculatus population, designated CHR, was identified in 2012 in Champaign County, IL, and previously characterized as resistant to herbicides from six site-of-action groups: 2,4-D (Group 4), acetolactate synthase inhibitors (Group 2), protoporphyrinogen oxidase inhibitors (Group 14), 4-hydroxyphenylpyruvate dioxygenase inhibitors (Group 27), photosystem II inhibitors (Group 5), and very long chain fatty acid synthesis inhibitors (Group 15). Recently, ineffective control of CHR was observed in the field after dicamba application. Therefore, this research was initiated to confirm dicamba resistance, quantify the resistance level and investigate its inheritance in CHR. Multiple field trials were conducted at the CHR location to confirm poor control with dicamba and compare dicamba treatments with other herbicides. Greenhouse trials were conducted to quantify the resistance level in CHR and confirm genetic inheritance of the resistance. In field trials, dicamba did not provide more than 65% control, while glyphosate and glufosinate provided at least 90% control. Multiple accessions were generated from controlled crosses and evaluated in greenhouse trials. Greenhouse dicamba dose-response experiments indicated a resistance level of 5 to 10-fold relative to sensitive parental line. Dose-response experiments using F1 lines indicated that dicamba resistance was an incompletely dominant trait. Segregation analysis with F2 and backcross populations indicated that dicamba resistance had moderate heritability and was potentially a multigenic trait. Although dicamba resistance was predominantly inherited as a nuclear treat, minor maternal inheritance was not completely ruled out. To our knowledge, CHR is one of the first cases of dicamba resistance in A. tuberculatus. Further studies will focus on elucidating the genes involved in dicamba resistance.

Confirmation of a five‐way herbicide‐resistant Amaranthus tuberculatus population in North Carolina

“…This result provides evidence that this population likely was intro- (Bobadilla et al, 2022;Shergill, Barlow, et al, 2018). Evolved resistance to glufosinate has been confirmed in A. palmeri in the midsouth United States and North Carolina (Heap, 2023;Noguera et al, 2022).…”

“…The number of effective herbicide options to control the Surry County population is limited. While the auxin herbicides (i.e., 2,4‐D and dicamba) effectively controlled the Surry County population, A. tuberculatus populations resistant to dicamba and 2,4‐D have been confirmed in the Midwest United States (Bobadilla et al, 2022; Shergill, Barlow, et al, 2018). Evolved resistance to glufosinate has been confirmed in A. palmeri in the midsouth United States and North Carolina (Heap, 2023; Noguera et al, 2022).…”

Investigation of inquiries on weed control efficacy of XtendiMax® herbicide with VaporGrip® technology

“…The variation in dicamba sensitivity observed in SD-AMATA-1 compared with the sensitive control may be attributed to a reduction in sensitivity, or to a natural variation that exists in weed accessions, or both (Crespo et al 2016;Hamberg et al 2023;Kumar et al 2020;Singh et al 2020). Furthermore, seasonal variability has been shown to influence the efficacy of synthetic auxins including dicamba and 2,4-D herbicides (Bobadilla et al 2022;Johnston et al 2019;Shergill et al 2018;Shyam et al 2022). The natural variability, particularly in Amaranthus spp.…”

Using soybean chaff lining to manage waterhemp (Amaranthus tuberculatus) in a soybean–corn rotation

“…Amaranthus tuberculatus is well adapted to no-till crop systems and can reduce corn and soybean grain yields by more than 40% if left uncontrolled (Hager et al 2002; Steckel and Sprague 2004). It has evolved resistance to seven different herbicide groups, including synthetic auxins (2,4-D and dicamba) and inhibitors of enolpyruval shikimate phosphate synthase (glyphosate), acetolactate synthase, photosystem II, protoporphyrinogen oxidase, 4-hydroxyphenylpyruvate dioxygenase, and very-long-chain fatty-acid synthesis (Bobadilla et al 2022; Tranel 2021).…”