Taxonomic evaluation of Italian populations of Lolium spp resistant and susceptible to diclofop-methyl

A comprehensive research project was set up to characterize by different approaches some Italian populations of Lolium spp susceptible and resistant to diclofop-methyl. The present study was aimed at the taxonomic identification of these Lolium populations on the basis of the electrophoretic analysis of seed reserve proteins. Electrophoresis confirmed the great range of variation detected by preliminary morphological analysis. Approximately half the individuals in each population could be classified as belonging to Lolium multiflorum or Lolium rigidum, the most common Lolium species present in the area. However, electrophoretic patterns revealed a significant number (40-60%) of hybrid individuals in all populations. The origin of these off-types was postulated as resulting from both intrageneric hybridization among different Lolium species and intergeneric hybridization between Lolium and Festuca genera. No significant differences were detected in the taxonomy of herbicide-susceptible and-resistant populations.