Inheritance of resistance to 2,4‐D and chlorsulfuron in a multiple‐resistant population of Sisymbrium orientale

• Published in: Pest management science 2015-11, Vol.71 (11), p.1523-1528
• Main Authors: Preston, Christopher, Malone, Jenna M
• Format: Article
• Language: English
• Subjects: 2,4-D; 2,4-Dichlorophenoxyacetic Acid - pharmacology; 4-D; acetolactate synthase; Acetolactate Synthase - antagonists & inhibitors; alleles; Brassicaceae - drug effects; Brassicaceae - genetics; chlorsulfuron; cross resistance; crossing; dominant genes; dose response; epinasty; Genes; Genes, Plant; herbicide resistance; Herbicide Resistance - genetics; Herbicides; Herbicides - pharmacology; inheritance; inheritance (genetics); major genes; multiple resistance; Mutation; Pest control; Plant resistance; Pollen; population; progeny; Sisymbrium; Sisymbrium orientale; site-directed mutagenesis; South Australia; Sulfonamides - pharmacology; target-site mutation; Triazines - pharmacology
• ISSN: 1526-498X; 1526-4998
• DOI: 10.1002/ps.3956

BACKGROUND: A population of Sisymbrium orientale from South Australia has multiple resistance to auxinic herbicides and inhibitors of acetohydroxyacid synthase (AHAS). Inheritance of resistance to 2,4‐D and chlorsulfuron was studied in this population. RESULTS: Crosses were made between seven resistant individuals as pollen donors to seven susceptible individuals. Sixteen F₁ individuals from three crosses were identified by their lack of strong epinasty when treated with 200 g 2,4‐D ha⁻¹. These individuals were selfed, and segregation analysis of strong epinasty in the resulting progeny fitted a 3:1 ratio for resistant:susceptible individuals when treated with 200 g 2,4‐D ha⁻¹, as predicted by a single major gene. A detailed dose–response analysis of the F₂ populations to 2,4‐D confirmed single‐gene inheritance. Analysis of segregation to 1 g chlorsulfuron ha⁻¹, a concentration that kills all susceptible individuals, was unable to determine the mode of inheritance. A detailed dose–response analysis indicated that two genes contributed to chlorsulfuron resistance: a dominant target‐site mutation of Pro 197 to Ser and a second gene with dose‐dependent dominance. CONCLUSIONS: This population has a single dominant allele conferring 2,4‐D resistance, whereas two genes contribute to chlorsulfuron resistance. Single dominant gene inheritance demonstrates that 2,4‐D resistance can be readily selected. © 2014 Society of Chemical Industry