Molecular analysis for target site resistance in isoproturon resistant littleseed canarygrass (Phalaris minor Retz.)

摘要

Herbicide-resistant weeds are a constraint to weed management in many cropping regionsaround the world. Littleseed canarygrass (Phalaris minor Retz.), the most predominant weed of wheatcrop has developed resistance against isoproturon in North-Western Indo-Gangetic plains of India. Theherbicide-binding region of the chloroplast psbA gene from a total of eight biotypes of P. minorresistant and susceptible to isoproturon was selectively amplified using PCR. Sequence analysis of thefragment from five herbicide-resistant biotypes and three sensitive biotypes exhibited none of the sixsubstitutions as reported in other weed species of the D1 protein encoded by the psbA gene. The lack ofmutations in herbicide binding region of psbA gene of isoprotutron resistant biotypes indicated thattarget-site resistance mechanism does not account for resistance rather resistance to this herbicide canbe attributed to non target-site resistance mechanism.