中文摘要：

【目的】分析大麦对新型除草剂丙酯草醚的生理反应,研究该除草剂处理对大麦幼苗的生理指标及根系细胞亚显微结构、有丝分裂的影响,为明确丙酯草醚在大麦田的使用安全性和作用机理奠定理论基础。【方法】在大麦四叶期喷施不同浓度丙酯草醚,分析处理后乙酰乳酸合成酶（ALS）活性、蛋白含量、叶绿素荧光参数、叶绿素含量、光合速率的变化趋势,并研究100 mg·L-1浓度丙酯草醚对根尖细胞发育的影响。【结果】田间推荐浓度100 mg·L-1丙酯草醚在处理初期对大麦幼苗的影响较小,但随处理时间延长,该浓度处理对大麦叶片ALS活性、蛋白含量、光合系统各项参数的抑制作用加剧,并造成根尖细胞液泡体积减小、数量减少、微粒体数量增多、有丝分裂指数降低等现象。500、1 000 mg·L-1浓度处理在不同时期对大麦各项生理指标均表现出显著的抑制作用。【结论】大麦对100 mg·L-1丙酯草醚在处理后期反应较为敏感,500、1 000 mg·L-1浓度处理对苗期大麦不安全,光合系统受抑制及线粒体中微粒体的变化可能与丙酯草醚的作用机理有关。

英文摘要：

【Objective】In order to define the safety and mechanism of new herbicide propyl 4-（2-（4,6-dimethoxypyrimidin-2-yloxy）benzylamino） benzoate（ZJ0273） to barley,this paper investigated the physiological effect of ZJ0273 on the root-tip cell ultrastructural development and mitosis in barley.【Method】 Effects of different concentrations of ZJ0273 applied at 4th leaf stage on acetolactate synthase（ALS） activity,protein content,photosystem II quantum characteristics,SPAD,net photosynthesis（Pn） and 100 mg？L-1 ZJ0273 on the development of root-tip cell were analyzed by various physiological measurements and microscopy techniques.【Result】The inhibited effect of 100 mg？L-1 ZJ0273 treatment（also a recommended concentration used in the field） on the growth of barely seedlings was slight at first,but this treatment inhibited significantly the ALS activity,protein content,photosynthetic system of barley seedlings along with the prolongation of treatment durations.The results also showed that the volume and number of vacuoles as well as mitotic index in treated cells were decreased,while the number of microbodies was increased.Both of 500 and 1 000 mg？L-1 ZJ0273 treatments inhibited the physiological index of barley at different treatment times.【Conclusion】 Barley seedlings are sensitive to herbicide ZJ0273 at concentration of 100 mg？L-1at late stage and unsafe at 500 and 1000 mg？L-1.The inhibitive effect of ZJ0273 on photosystem II and the change of microbody in mitochondria might be related to the mechanism of this new herbicide.