title: Two recessive gene inheritance for triallate resistance in Avena fatua L.
abstract: Extensive use of the preemergence herbicide triallate over the last three decades has selected for resistant (R) Avena fatua L. populations in several areas of the United States and Canada. R plants are also cross-resistant to the unrelated pyrazolium herbicide difenzoquat. We made reciprocal crosses between inbred R and susceptible (S) lines to determine the genetic basis of triallate resistance. Seeds from parental lines and F(2) populations were treated with soil applications of 0.275, 0.55, or 1.1 kg/ha triallate in the greenhouse and plant heights recorded after 37 days. Surviving F(2) plants were selfed and the resulting F(3) families were screened with 1.1 kg/ha triallate. In the F(2) populations, assortment of S and R phenotypes fit a 15:1 segregation ratio, suggesting that resistance was controlled by the two independently segregating recessive genes TRR1 and TRR2. None of the 912 F(3) progeny from 51 R F(2) individuals was susceptible to triallate treatment, further supporting a two-gene mode of inheritance. There was a possible maternal effect on susceptibility at the highest triallate rate tested.
authors: Department of Plant Sciences and Plant Pathology, Leon Johnson Hall, Montana State University, Bozeman, MT 59717, USA.
authors: A J
authors: AJ
authors: Kern
authors: T M
authors: TM
authors: Myers
authors: M
authors: M
authors: Jasieniuk
authors: B G
authors: BG
authors: Murray
authors: B D
authors: BD
authors: Maxwell
authors: W E
authors: WE
authors: Dyer
mesh_terms: D018554:Avena / Q000187:drug effects / Q000235:genetics*; D003433:Crosses, Genetic; D004351:Drug Resistance / Q000235:genetics*; D017343:Genes, Plant; D005808:Genes, Recessive; D006540:Herbicides / Q000494:pharmacology*; D011720:Pyrazoles / Q000378:metabolism; D014214:Triallate / Q000494:pharmacology*
chemical_list: D006540:Herbicides; D011720:Pyrazoles; C031394:difenzoquat; D014214:Triallate