Molecular markers indicate intraspecific variation in the control of Echinochloa spp. with quinclorac

Some species of the genus Echinochloa are troublesome weeds in rice fields. The taxonomy of this genus leads to confusion in many cases due to its gre at morphological diversity. Because of the differential sensitivity to the herbicide quinclorac shown by Echinochloa spp., it was necessary to assess the botanical and molecular characterization of this weed. Echinochloa colo num, E, oryzoides and E. oryzicola were very susceptible to quinclorac trea tment; by contrast, E. crus-galli and E. hispidula showed some degree of na tural tolerance. Physiological and molecular results agreed with the botani cal classification of che genus Echinochloa in Flora Europea. The importanc e of these results is due to yield losses produced by the infestation of Ec hinochloa and the need for a strategy for Echinochloa management depending on the distribution of the Echinochloa species.