Resistance of various biotypes of Canary grass (phalaris. Spp) to acetyl-CoA carboxylase-inhibiting herbicides.

Abstract

Little seed canary grass (<em>Phalaris minor</em> L.) is a major weed in wheat fields in some parts of Iran. To evaluate the efficacy of molecular and greenhouse methods in detecting the resistance of 49 biotypes of canary grass(<em>Phalaris. Spp)</em> to acetyl-CoA carboxylase-inhibiting herbicides, two methods including whole plant screening and PCR-based molecular methods were applied. Results showed that there were resistant biotypes (ile-1781-Leu) among the studied weed populationand the similarity between greenhouse and molecular methods was 67%. According to the molecular method, an isoleucine (ile) 1781 to leucine (leu) mutation in plastidicACCase enzyme of 30 biotypes (67% of biotypes) was identifiedas a mutation endowing to the clodinafop-propargyl resistance. The partial differences of about 33% between greenhouse and molecular methods can be explained by mutation in another location or through another metabolism –based mechanism.