Herbicide resistance provides a threat to the Australian Rice Industry. Already, resistance has been recorded in dirty dora, arrowhead and starfruit to the herbicide bensulfuron (LondaxÒ) and may necessitate significant changes to the cultural programs for rice. At the request of the Rice Research Committee, a preliminary study was undertaken to evaluate whether the resistance was based on a single gene and how the resistance might develop through generations, using material generated through the Charles Sturt University herbicide resistance testing service. This report outlines the findings of that investigation which is unable to provide unequivocal answers to the questions raised, but suggests that the process is more complex. 2004, 19pp, Pub. No, 04/009