Michitte P, De Prado R, Espinosa N, Gauvrit C
Departamento de Química Agrícola, Universidad de Córdoba, España.
Commun Agric Appl Biol Sci. 2005;70(3):507-13.
Lolium multiflorum (Italian ryegrass) has recently demonstrated itself to be poorly controlled with glyphosate in cereal crops of South Chile. The concentration of glyphosate necessary to reduce shoot length by 50% (ED50) in seedlings, after eight days of root contact was 7.3-fold in the resistant Vil-1 than in the susceptible (S) biotype. The obtained spray retention values were higher on S than the resistant (Vil-1) biotype. Contact angles measured on the adaxial surface of S and Vil-1 were similar. However, on the abaxial surface contact angles were of 63 degrees on Vil-1 as compared to 42 degrees on S. A greater glyphosate uptake was observed through the abaxial surface of S. Regarding translocation, glyphosate accumulated mainly in the tip of the treated leaf of Vil-1, 24 h after treatment. It was afterwards also well distributed to the rest of the leaves and roots, as in the susceptible biotype. Nevertheless, 14C-glyphosate remained higher in the foliar apex of Vil-1. Hence, resistance to glyphosate by the Vil-1 Lolium multflorum biotype seems to involve a lower uptake through the abaxial leaf surface and a different migration pattern.
多花黑麦草（意大利黑麦草）最近在智利南部的谷类作物中表现出对草甘膦的抗性。在根部接触草甘膦八天后，抗性Vil-1生物型幼苗的草甘膦浓度降低50%（ED50）所需的浓度是敏感（S）生物型的7.3倍。在S生物型上获得的喷雾保留值高于抗性（Vil-1）生物型。在S和Vil-1的近轴表面测量的接触角相似。然而，在远轴表面，Vil-1的接触角为63度，而S的接触角为42度。通过S的远轴表面观察到更大的草甘膦吸收。关于转运，处理后24小时，草甘膦主要积累在Vil-1处理叶片的尖端。之后，它也像在敏感生物型中一样，很好地分布到其余叶片和根部。然而，14C-草甘膦在Vil-1的叶尖中仍然较高。因此，Vil-1多花黑麦草生物型对草甘膦的抗性似乎涉及通过叶片远轴表面的较低吸收和不同的迁移模式。
