Department of Applied Chemistry, China Agricultural University, No. 2 of Yuan Ming Yuan Xilu, Haidian District, Beijing 100193, China.
Department of Applied Chemistry, China Agricultural University, No. 2 of Yuan Ming Yuan Xilu, Haidian District, Beijing 100193, China.
Pestic Biochem Physiol. 2018 Apr;146:7-12. doi: 10.1016/j.pestbp.2017.12.008. Epub 2017 Dec 28.
The resistance levels to glyphosate and target-site based resistance mechanisms in susceptible (S) and resistant (R) Conyza canadensis (L.) populations, which were collected from apple orchards around areas of Bohai seas and Loess Plateau in China, were investigated. Among forty C. canadensis populations, eighteen populations (45%) were still susceptible; fourteen populations (35%) evolved low resistance levels resistance to glyphosate with resistance index (RI) of 2.02 to 3.90. In contrast, eight populations (20%) evolved medium resistance levels with RI of 4.35 to 8.38. The shikimic acid concentrations in R populations were highly negative relative with the glyphosate resistance levels in C. canadensis, the Pearson correlation coefficient was -0.82 treated by glyphosate at 1.8mg/L. Three 5-enoylpyruvylshikimate 3'-phosphate synthase genes (EPSPS1, EPSPS2 and EPSPS3) were cloned in all S and glyphosate-resistant C. canadensis populations. No amino acid substitution was identified at site of 102 and 106 in three EPSPS genes, which were reported to confer glyphosate resistance in other weed species. The relative expression level of EPSPS mRNA in R populations (SD07, LN05, SHX06 and SD09) was 4.5 to 13.2 times higher than in S biotype. The Pearson correlation coefficient between EPSPS expression levels and RI was 0.79, which indicated the over expression of EPSPS mRNA may cause these R populations evolve higher resistance level to glyphosate.
研究了来自中国渤海湾地区和黄土高原苹果园的敏感（S）和抗药性（R）加拿大飞蓬（Conyza canadensis（L.））种群对草甘膦的抗性水平和靶标位点抗性机制。在 40 个加拿大飞蓬种群中，有 18 个种群（45%）仍然敏感；14 个种群（35%）对草甘膦表现出低水平的抗性，抗性指数（RI）为 2.02-3.90。相比之下，有 8 个种群（20%）对草甘膦具有中等水平的抗性，RI 为 4.35-8.38。R 种群中的莽草酸浓度与加拿大飞蓬中的草甘膦抗性水平呈高度负相关，用 1.8mg/L 草甘膦处理时，皮尔逊相关系数为-0.82。在所有 S 型和抗草甘膦的加拿大飞蓬种群中都克隆了三个 5-烯酰基-莽草酸-3'-磷酸合酶基因（EPSPS1、EPSPS2 和 EPSPS3）。在三个 EPSPS 基因的 102 和 106 位点未发现氨基酸取代，这些位点在其他杂草物种中被报道可赋予草甘膦抗性。R 种群（SD07、LN05、SHX06 和 SD09）中 EPSPS mRNA 的相对表达水平比 S 型高 4.5 到 13.2 倍。EPSPS 表达水平与 RI 之间的皮尔逊相关系数为 0.79，这表明 EPSPS mRNA 的过度表达可能导致这些 R 种群对草甘膦产生更高的抗性水平。
