Inheritance of dicamba-resistance in allotetraploid Chenopodium album

BACKGROUND: Chenopodium album L. is a troublesome weed in spring-planted crops, and different levels of ploidy have been documented for this weed species. A population of C. album has evolved resistance to dicamba. The level of ploidy and inheritance of dicamba resistance was studied in this population.

RESULTS: The resistant and susceptible individuals of C. album were confirmed as tetraploid by flow cytometry. Pair-crosses were made between ten resistant and susceptible individuals. Eight F1 individuals from five crosses were confirmed resistant aftertreating with dicamba at 400 g a.e. ha−1. These individuals were selfed, and the response of their progenies to dicamba was assessed in dose–response experiments, and the results confirmed the resistance trait was dominant. Furthermore, an analysis of the segregation patterns revealed that the segregation response of all F2 progenies fitted a 3:1 (resistant/susceptible) ratio when treated with dicamba at 200, 400 and 800 g a.e. ha−1, suggesting a single gene was responsible for dicamba resistance.

CONCLUSIONS: Dicamba resistance in the studied tetraploid population of C. album is governed by a single dominant gene. This type of inheritance suggests that selection for dicamba resistance can occur readily.