A putative resistant johnsongrass (Sorghum halepense L.) population from a cotton field in northern Greece was studied to determine the levels of resistance to acetyl-CoA carboxylase (ACCase)-inhibiting herbicides and elucidate related mechanisms of resistance. The johnsongrass population showed cross-resistance to the ACCase-inhibiting herbicides fluazifop-p-butyl, quizalofop-p-ethyl, and propaquizafop, with poor levels of control even with four times of the recommended rates of these herbicides. However, the johnsongrass population was highly sensitive (100% control) to the ACCase inhibitors cycloxydim and clethodim and to the acetolactate synthase inhibitor nicosulfuron. Amplification and sequencing of the ACCase gene fragment from johnsongrass plants revealed an Ile to Asn substitution at codon 2041 of the ACCase enzyme. This is the first record of a molecularly confirmed ACCase-resistant johnsongrass population from cotton fields in Europe. These findings highlight a threat against the sustainable use of ACCase-inhibiting herbicides in controlling johnsongrass and other grasses in cotton fields.

中文翻译：

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鉴定来自希腊北部棉田的乙酰辅酶 A 羧化酶抗性约翰逊草（高粱 halepense L.）种群

研究了来自希腊北部棉田的推定抗性约翰逊草 ( Sorghum halepense L.) 种群，以确定对抑制乙酰辅酶 A 羧化酶 (ACCase) 的除草剂的抗性水平，并阐明相关的抗性机制。约翰逊草种群对抑制 ACCase 的除草剂正丁氟​​禾草灵、精喹禾草灵和异喹禾灵显示出交叉抗性，即使这些除草剂的推荐用量是四倍，控制水平也很差。然而，约翰逊草种群对 ACCase 抑制剂环氧定和烯草酮以及乙酰乳酸合酶抑制剂烟嘧磺隆高度敏感（100% 控制）。ACCase的扩增和测序来自 johnsongrass 植物的基因片段揭示了 ACCase 酶密码子 2041 处的 Ile 到 Asn 的取代。这是来自欧洲棉田的分子确认的 ACCase 抗性约翰逊草种群的第一份记录。这些发现突出了在控制棉田中的约翰逊草和其他草类时可持续使用 ACCase 抑制性除草剂的威胁。