Passaggio della resistenza agli erbicidi dal riso coltivato al riso crodo.

Abstract The risks caused by the adoption of agricultural practices based on the use of herbicide resistant cultivars and of the corresponding herbicides have been evaluated in order to study the possible transfer of the resistant gene from the resistant cultivar (Oryza sativa L.) to the weedy rice (Oryza sativa f. spontanea). A first experiment, carried out with a glufosinate ammonium resistant transgenic line, shows that, despite herbicide application and manual removal of weedy rice plants, the gene transfer for resistance can happen. This has been confirmed, concerning the resistance to imidazolinone herbicide, from the exploration of 16 rice fields in northern Italy: in 9 fields cultivated with an imidazolinone resistant cultivar, and treated with the appropriate herbicide, weedy rice individuals carrying the resistance gene have been detected.