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Measuring Rates of Herbicide Metabolism in Dicot Weeds with an Excised Leaf Assay
Published on: September 7, 2015
Genetic architecture underlying HPPD-inhibitor resistance in a Nebraska Amaranthus tuberculatus population
Brent P Murphy1, Roland Beffa2, Patrick J Tranel1
1Department of Crop Sciences, University of Illinois, Urbana, IL, USA.
Background:
Amaranthus tuberculatus is a problematic weed species in Midwest USA agricultural systems. Inhibitors of 4-hydroxyphenylpyruvate dioxygenase (HPPD) are an important chemistry for weed management in numerous cropping systems. Here, we characterize the genetic architecture underlying the HPPD-inhibitor resistance trait in an A. tuberculatus population (NEB).
Results:
Dose-response studies of an F1 generation identified HPPD-inhibitor resistance as a dominant trait with a resistance factor of 15.0-21.1 based on dose required for 50% growth reduction. Segregation analysis in a pseudo-F2 generation determined the trait is moderately heritable (H2 = 0.556) and complex. Bulk segregant analysis and validation with molecular markers identified two quantitative trait loci (QTL), one on each of Scaffold 4 and 12.
Conclusions:
Resistance to HPPD inhibitors is a complex, largely dominant trait within the NEB population. Two large-effect QTL were identified controlling HPPD-inhibitor resistance in A. tuberculatus. This is the first QTL mapping study to characterize herbicide resistance in a weedy species.
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