Fitness Costs Associated to an Ile2041Asn Mutation in the Geophyte Sorghum halepense Resistant to ACCase-Inhibiting Herbicides

Sorghum halepense (L.) Pers. is a troublesome weed of maize which reproduces through seeds and rhizomes. Resistance to ACCase-inhibiting herbicides due target-site mutation Ile-Asn in position 2041 the ACCase gene was confirmed several populations Italy. The presence fitness costs related allelic variant Ile2041Asn has never been investigated ACCase-resistant S. . Three growth analyses pot experiments were performed starting from rhizome buds (Exp1 Exp3) or seed (Exp2). Plant development monitored throughout life cycle destructive samplings. responsible for resistance inhibitors detected all plants included using Cleaved Amplified Polymorphic Sequence method. Classical analysis multiple sampling Exp2) allometric relationships calculated different dry weight plant parts experiments. Allometric showed that susceptible (S) resistant (R) biotypes allocated biomass differently reproductive structures: S on average 30% more panicles, whereas R 12% rhizomes than populations. This evident when started buds. Reproductive allocation effort higher biotypes, respectively. production lower biotype can significantly impact evolution herbicide under continuous application with same mode action. A medium-long term management strategy implements appropriate soil tillage crop rotation taking into account attitude should be devised.