Multiple resistance of acetolactate synthase and protoporphyrinogen oxidase inhibitors in Euphorbia heterophylla biotypes

• Published in: Journal of environmental science and health. Part B, Pesticides, food contaminants, and agricultural wastes Pesticides, food contaminants, and agricultural wastes, 2005, Vol.40 (1), p.101-109
• Main Authors: Trezzi, M.M, Felippi, C.L, Mattei, D, Silva, H.L, Nunes, A.L, Debastiani, C, Vidal, R.A, Marques, A
• Format: Article
• Language: English
• Subjects: acetolactate synthase; Acetolactate Synthase - antagonists & inhibitors; Acetolactate Synthase - drug effects; Acetolactate Synthase - pharmacology; Adaptation, Physiological; Biological and medical sciences; biotypes; Brazil; Chemical control; cross resistance; Drug Resistance, Multiple; Environmental Monitoring; enzyme inhibitors; Enzyme Inhibitors - pharmacology; Euphorbia - enzymology; Euphorbia - growth & development; Euphorbia heterophylla; Fomesafen; Fundamental and applied biological sciences. Psychology; geographical distribution; herbicide resistance; Herbicide resistant; Herbicides - pharmacology; Imazethapyr; Oxidoreductases Acting on CH-CH Group Donors - antagonists & inhibitors; Oxidoreductases Acting on CH-CH Group Donors - drug effects; Oxidoreductases Acting on CH-CH Group Donors - pharmacology; Parasitic plants. Weeds; Pest Control; Phytopathology. Animal pests. Plant and forest protection; Population Dynamics; Protoporphyrinogen Oxidase; Weeds; Wild poinsettia
• ISSN: 0360-1234; 1532-4109
• DOI: 10.1081/PFC-200034254

Resistance to acetolactate synthase (ALS)-inhibiting herbicides in Brazil has been documented for six species. The probability to select biotypes of Euphorbia heterophylla (EPPHL) with multiple resistance increases in the same order of magnitude as the use of other herbicides belonging to only one mechanism of action. The objectives of this work were to evaluate the distribution of resistant populations (R) in the states of the Paraná and Santa Catarina; to determine the existence of populations of EPHHL with multiple resistance to ALS and PROTOX inhibitors, and to confirm the occurrence of cross resistance to compounds of these mechanisms of action. Seeds of EPHHL of areas with suspected resistance had been sampled in 97 places during 2003. In the greenhouse experiment samples of each population were sprayed with imazethapyr or fomesafen, at only one rate. To identify the resistant ones they were sprayed with different levels of the herbicides imazethapyr and fomesafen. Later they were sprayed with diverse herbicides of the same mechanisms of action to confirm the multiple/cross resistance. There is widespread distribution in the region of populations with resistance to ALS inhibitors. Some biotypes demonstrated resistance to herbicides from the two mechanisms of action. The resistance factor (FR), or the relation of resistance between R and susceptible biotypes, confirms the existence of two biotypes of EPHHL with cross resistance to several herbicides inhibitors of ALS and PROTOX.