Translocation Studies With Endothal‐¹⁴c in Potamogeton Nodosus Poir.

Summary. Plants of Potamogeton nodosus, a submersed aquatic, were treated with the di‐sodium salt of 7‐oxabicyclo(2,2,l)heptane‐2,3‐dicarboxylic acid‐ 14 C (endothal‐ 14 C). Gross radioautographs showed that the 14 C label moved from mature photosynthesizing leaves and accumulated in the apices and developing secondary plants. Similar results were obtained with mid‐leaf, stem (internode) and winter‐bud applications. No move‐ment of radioactivity occurred following root treatment. The results indicate symplastic translocation of endothal‐ 14 C when applied to the leaf, stem or winter bud. It is suggested that endothal can cause the death of plants by direct injury to root tissues subsequent to absorption. Recherches sur la migration de l'endothal‐ 14 C dans le Potamogeton nodosus Poir.