Genetic architecture underlying HPPD-inhibitor resistance in a Nebraska Amaranthus tuberculatus population

Abstract

BACKGROUND: Amaranthus tuberculatus is a primary driver weed species throughout the American Midwest. 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/sensitive ratio of 15.0-21.1. 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.

The blackgrass genome reveals patterns of non‐parallel evolution of polygenic herbicide resistance

“…(2021), that NTSR in Ipomoea purpurea is conferred by multiple loci. Similarly, separate studies of HPPD resistance in different Amaranthus tuberculatus populations have highlighted the distal regions of the genome showing signatures of selection for resistance (Kohlhase et al ., 2018; Murphy et al ., 2021). Our findings, combined with our co‐expression network analysis, provide strong evidence that NTSR among blackgrass populations is divergent at the genomic level.…”

Identification of field resistance to HPPD-inhibiting herbicides in wild radish (Raphanus raphanistrum)

“…This discrepancy could be partially explained by the complex inheritance of metabolic resistance as documented in Amaranthus spp. (Küpper et al 2018;Murphy et al 2021); population variability in the detoxification of different…”