Vazquez-Garcia Jose G, Palma-Bautista Candelario, Rojano-Delgado Antonia Maria, De Prado Rafael, Menendez Julio
Agricultural Chemistry and Soil Sciences, University of Córdoba, 14014 Cordoba, Spain.
Departamento de Ciencias Agroforestales, Escuela Tecnica Superior de Ingenieria, Campus de La Rabida, Universidad de Huelva, Palos de la Frontera, 21819 Huelva, Spain.
Plants (Basel). 2020 Mar 3;9(3):313. doi: 10.3390/plants9030313.
Six Johnsongrass populations suspected of being glyphosate resistant were collected from railways and freeways near Cordoba (SW Spain), where glyphosate is the main weed control tool. The 50% reduction in shoot fresh weight (GR) values obtained for these six populations ranged from 550.4 to 1169 g ae ha, which were 4.2 to 9 times greater than the value obtained for the susceptible population. Glyphosate was equally metabolized to the same extent in both resistant and susceptible populations, with no significant differences in either 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) inhibition or basal activity. No amino acid substitutions were observed in any of the resistant populations. Slight but significant differences in glyphosate penetration were observed among some but not all of the resistant populations and for the times of incubation assayed, although these differences were not considered further. The proposed primary mechanism of resistance in these six glyphosate-resistant Johnsongrass populations is reduced herbicide translocation, because the amount of glyphosate that translocated from treated leaves to shoots and roots in the susceptible population was double that observed in the resistant populations. As glyphosate multiple resistance due to more than one mechanism is not uncommon, this is the first time that glyphosate-resistant Johnsongrass populations have been fully described for all known mechanisms.
从科尔多瓦（西班牙西南部）附近的铁路和高速公路收集了六个疑似抗草甘膦的约翰逊草种群，在该地草甘膦是主要的杂草控制工具。这六个种群的地上部鲜重减少50%（GR）值在550.4至1169克酸当量/公顷之间，是敏感种群所得值的4.2至9倍。在抗性和敏感种群中，草甘膦的代谢程度相同，5-烯醇丙酮酰莽草酸-3-磷酸合酶（EPSPS）抑制或基础活性均无显著差异。在任何抗性种群中均未观察到氨基酸取代。在一些但并非所有抗性种群以及所测定的孵育时间中，草甘膦渗透存在轻微但显著的差异，不过未进一步考虑这些差异。这六个抗草甘膦约翰逊草种群中拟议的主要抗性机制是除草剂转运减少，因为在敏感种群中从处理叶片转运到地上部和根部的草甘膦量是抗性种群中观察到的两倍。由于由多种机制导致的草甘膦多重抗性并不罕见，这是首次对所有已知机制的抗草甘膦约翰逊草种群进行全面描述。
