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 midwestern United States. The rapid evolution and selection herbicide-resistance traits A. a major challenge managing this species. An population, designated CHR, was identified 2012 Champaign County, IL, previously characterized as resistant to herbicides from six site-of-action groups: 2,4-D (Group 4), acetolactate synthase inhibitors 2), protoporphyrinogen oxidase 14), 4-hydroxyphenylpyruvate dioxygenase 27), photosystem II 5), very-long-chain fatty-acid synthesis 15). Recently, ineffective control CHR observed field after dicamba application. Therefore, research initiated confirm resistance, quantify resistance level, investigate its inheritance CHR. Multiple trials were conducted at location poor with compare treatments other herbicides. Greenhouse level genetic resistance. In trials, did not provide more than 65% control, while glyphosate glufosinate provided least 90% control. accessions generated controlled crosses evaluated greenhouse trials. dose–response experiments indicated 5- 10-fold relative sensitive parental line. Dose–response using F 1 lines that an incompletely dominant trait. Segregation analysis 2 backcross populations had moderate heritability potentially multigenic Although predominantly inherited nuclear trait, minor maternal completely ruled out. To our knowledge, first cases . Further studies will focus on elucidating genes involved