BACKGROUND: Multiple-herbicide resistance in Lolium perenne spp. multiflorum has evolved in many areas in Oregon. To manage the resistant populations, the resistance patterns must be determined. In this study, a population (CT) suspected to be resistant to sulfometuron and hexazinone was collected from a Christmas tree plantation. RESULTS: The CT population is resistant to at least six herbicides with four different mechanisms of action: atrazine (>16-fold), diuron (2.4-fold), glyphosate (7.4-fold), hexazinone (3.1-fold), imazapyr (1.8-fold) and sulfometuron (>16-fold). Two mutations, Trp-591-Leu and Ser-264-Gly, were identified in the acetolactate synthase (ALS) and psbA gene respectively. No previously reported mutation in the 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) gene was found. Less shikimic acid accumulated in the CT plants than in the susceptible plants after treatment with glyphosate at 0.6 kg AE ha(-1) . CONCLUSION: This study suggests that the multiple resistance patterns of Lolium perenne spp. multiflorum populations can be complex, but that chemical control options to manage these populations exist. These remaining chemical options should be integrated with non-chemical management strategies to slow the spread of multiple-resistant biotypes in agroecosystems.
BACKGROUND: Multiple-herbicide resistance in Lolium perenne spp. multiflorum has evolved in many areas in Oregon. To manage the resistant populations, the resistance patterns must be determined. In this study, a population (CT) suspected to be resistant to sulfometuron and hexazinone was collected from a Christmas tree plantation. RESULTS: The CT population is resistant to at least six herbicides with four different mechanisms of action: atrazine (>16-fold), diuron (2.4-fold), glyphosate (7.4-fold), hexazinone (3.1-fold), imazapyr (1.8-fold) and sulfometuron (>16-fold). Two mutations, Trp-591-Leu and Ser-264-Gly, were identified in the acetolactate synthase (ALS) and psbA gene respectively. No previously reported mutation in the 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) gene was found. Less shikimic acid accumulated in the CT plants than in the susceptible plants after treatment with glyphosate at 0.6 kg AE ha(-1) . CONCLUSION: This study suggests that the multiple resistance patterns of Lolium perenne spp. multiflorum populations can be complex, but that chemical control options to manage these populations exist. These remaining chemical options should be integrated with non-chemical management strategies to slow the spread of multiple-resistant biotypes in agroecosystems.
Authors: James T Brosnan; Jose J Vargas; Gregory K Breeden; Logan Grier; Raphael A Aponte; Stefan Tresch; Martin Laforest Journal: Planta Date: 2015-09-09 Impact factor: 4.116
Authors: José G Vázquez-García; Ricardo Alcántara-de la Cruz; Candelario Palma-Bautista; Antonia M Rojano-Delgado; Hugo E Cruz-Hipólito; Joel Torra; Francisco Barro; Rafael De Prado Journal: Front Plant Sci Date: 2020-10-28 Impact factor: 5.753