Reaction of herbicide-resistant inbred sunflower lines to treatment with AHAS inhibitors

A study of a specially developed set of ten lines from a sunflower genetic collection revealed an identical response to treatment with AHASinhibiting herbicides in the maternal and paternal forms of the hybrids. The susceptible lines VK101 A and VK305 exhibited total plant death, scoring 7–9 on the phytotoxicity scale. The imidazolinoneresistant lines VK101imi A (ImrImr), VK1klp A (CLHA+CLHA+), VK302imi (ImrImr) and VK21klp (CLHA+CLHA+) were characterized by their resistance to the herbicides EuroLightning and EuroLightning Plus and susceptibility to the herbicide Sunflo. This indicates that they do not have crossresistance to tribenuronmethyl. The sulfonylurearesistant samples, VK1sur A and VK21sur (SurSur), exhibited good tolerance to the target herbicide Sunflo and showed partial crosstolerance to EuroLightning, with intermediate scores of 4–6. Plants of the new lines VK1air B and LG4air (AirAir) exhibited complete resistance to single doses of both Euro-Lightning and Sunflo, as well as to their combined treatment.