摘要
为探讨除草剂甲咪唑烟酸在土壤中的残留对后茬小麦幼苗生长和光合作用的影响，采用土壤添加法测定了在不同甲咪唑烟酸土壤残留浓度（0～1．2mg·kg^-1）下麦苗根系和地上部生长、叶片光合参数的变化。结果表明，随着土壤中甲咪唑烟酸残留浓度的增加，麦苗的株高、单株鲜重和干重呈现降低的趋势，添加甲咪唑烟酸对根系生长的抑制作用大于地上部，导致麦苗根冠比下降和生长不均衡。甲味唑烟酸处理均引起麦苗叶片叶绿素减少，暗呼吸速率上升。土壤中甲咪唑烟酸浓度较高时小麦光合速率显著受到抑制，1．2mg·kg^-1处理的抑制率最大，达38．39％，净光合速率下降的原因主要是非气孔因素限制导致的。以上结果说明，甲咪唑烟酸土壤残留会对后茬小麦产生严重的影响，生产中应注意控制甲咪唑烟酸使用剂量和安全间隔期。
Effects of different levels of imazapic residues （0-1.2 mg ·kg^-1） on the growth and photo- synthetic parameters of wheat seedlings as succeeding crop were evaluated by adding imazapie to soil of the simulated pot experiment. The results showed that plant height, fresh weight and whole plant dry weight decreased with the increase of imazapic residues concentrations. Compared with the con- trol, the dry weight of above-ground and under-ground parts under imazapic treatments decreased to different degree. The inhibition effects of imazapic treatments on the dry weight of under-ground parts were more obvious than that of above-ground parts, resulted in growth unbalance and change of the root/shoot ratio. All the imazapic treatments caused the decline of chlorophyll content in the leaves of wheat seedlings. Under high concentration of imazapic treatments, the net photosynthetic rate was in- hibited significantly. When the dose of imazapic residue was 1.2 mg ·kg^-1 , the maximum net photosynthetic rate decreased by 38.39 % than the control. The non-stomatal factors limited the net photo- synthetic rate, which meant that imazapic residue affected wheat photosynthetic mechanism. Above results indicated that imazapic residues can have significant negative effects on succeeding crop of wheat seedlings. In the production, we should pay attention to control the dosage of imazapie and the interval period of chemical safety.
出处
《麦类作物学报》
CAS
CSCD
北大核心
2013年第6期1226-1231,共6页
Journal of Triticeae Crops
基金
国家公益性行业(农业)科研专项(201203098)
关键词
甲咪唑烟酸
土壤残留
小麦
生物量
气体交换
Imazapic
Residues
Wheat
Gas exchange parameters
Biomass allocation
