新型除草剂丙酯草醚对油菜幼苗生长与根尖细胞活性的影响

Effect of New Herbicide ZJ0273 on Seedling Growth and Root Cell Viability of Brassica napus

【目的】研究新型油菜田除草剂丙酯草醚(ZJ0273)对甘蓝型油菜发芽期幼苗在生长发育及根尖细胞活性等方面的安全性影响,为进一步明确其作用机理奠定理论基础。【方法】利用生理生化方法探讨了ZJ0273处理对发芽期油菜茎根长、干物质积累、根系活力和根细胞膜透性等的影响,并运用FDA-PI荧光对染法及根尖压片法研究了该除草剂对油菜根尖细胞活性及有丝分裂的影响。【结果】ZJ0273处理对油菜幼苗干物质和苗高等性状的抑制作用随着处理浓度的升高和处理时间的延长而显著增强;10与100mg·L-1处理显著抑制了油菜幼苗根的生长且两处理间抑制效果无明显差异;1mg·L-1以下浓度的ZJ0273对油菜幼苗根系活力、细胞膜完整性几乎无显著影响,而10mg·L-1以上浓度处理则明显抑制根系活力且破坏细胞膜完整性;100mg·L-1ZJ0273处理抑制油菜根尖分生区细胞有丝分裂并使多数细胞停滞于分裂中期。【结论】发芽期是油菜对ZJ0273处理的敏感时期;10mg·L-1ZJ0273处理即抑制油菜幼苗的生长发育及影响根尖细胞活性,且抑制效果随处理浓度的升高和处理时间的延长而增大;对油菜幼苗较为安全的ZJ0273临界浓度为1mg·L-1。

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.