Abstract:

【Objective】This paper described the response of seedling growth and root cell viability of Brassica napus L. (rapeseed) to various concentrations of ZJ0273 treatments at germination stage to define the mechanism of this novel herbicide.【Method】Effects of different ZJ0273 treatments on dry matter, morphological characters, root oxidizability and cell membrane permeability of rapeseed seedlings were investigated by various physiological measurements. Root cell viability and mitosis as affected by herbicide treatments were also studied based on FDA-PI double staining and root-tip squashing method. 【Result】The results indicated that the inhibitive effects of ZJ0273 treatments on rapeseed dry matter and morphological characters were enhanced along with the increase of treatment concentrations and durations. Both of 10 and 100 mg?L-1 ZJ0273 treatments inhibited root development significantly. There were no distinct difference among 0, 0.1 and 1 mg?L-1 ZJ0273 treatments on root oxidizability and membrane permeability, compared with treatments at 10 and 100 mg?L-1 which obviously inhibited root cell viability and induced cell membrane disintegration. Furthermore, mitotic index of root-tip cells was declined and cell division was stopped at metaphase after being treated by 100 mg?L-1 ZJ0273. 【Conclusion】Rapeseed seedlings are very sensitive to herbicide ZJ0273 at germination stage. Treatment at 10 mg?L-1 ZJ0273 can significantly inhibit rapeseed growth and root viability, and the inhibitive effect is intensified with the increase of treatment concentrations and durations. The application of 1 mg?L-1 (critical concentration) is safe for rapeseed seedling growth.

Key words: rapeseed (Brassica napus L.), ZJ0273, root oxidizability, membrane permeability, FDA-PI, mitotic index