茶园土壤中三氯杀螨醇残留及胜红蓟杂草对其富集作用

Dicofol residues in soil from tea plantation and their accumulation by Ageratum conyzoides plants

采用气相色谱法测定了福建省武夷山、福州、宁德等地6个茶园土壤及覆盖植物胜红蓟(Ageratumconyzoides)中的三氯杀螨醇含量,结果表明:在所研究茶园土壤中,WYSXC3点三氯杀螨醇残留最高,为0.277 mg.kg-1外,其余均低于0.010 mg.kg-1;而胜红蓟所有样品都检出了三氯杀螨醇残留,地上组织和根中的平均残留量分别为2.831 mg.kg-1、0.753 mg.kg-1。以5个点土壤中三氯杀螨醇浓度为参照,胜红蓟茎叶与根BCFs平均值分别为236.359、65.284。采用盆栽试验方法,研究了胜红蓟根、茎叶对三氯杀螨醇的富集,结果表明,施药量为500 mg.kg-1时,土壤和胜红蓟茎叶中三氯杀螨醇的残留量均随时间延长而降低,分别由10 d时的3.301 mg.kg-1和2.965 mg.kg-1降到30 d时的1.313 mg.kg-1和1.477 mg.kg-1;而胜红蓟根中三氯杀螨醇残留随着时间延长而增加,由10 d时的4.541 mg.kg-1增加到30 d时的12.734 mg.kg-1。研究结果表明,胜红蓟对三氯杀螨醇具有富集作用。

Dieofol residues in soil and different tissues of Ageratum conyzoides plants collected from tea plantations in Wuyi mountain, Fuzhou and Ningde, Fujian were determined using gas chromatography. Accumulation of dicofol by A. conyzoides from soils was studied in the laboratory. Dicofol in soil ranged from 0 to 0. 277 mg · kg^-1 . A- mong them, the highest amount of residue, 0. 277 mg · kg^-1 , was found in soils from WYSXC3, while other samples were below 0. 010mg · kg^-1. The average BCFs for aerial tissues and roots of A. conyzoides were 236. 359 and 65. 284, respectively. The accumulation dynamics of dicofol by A. conyzoides was also studied in the laboratory. The dicofol residue in soil and aerial tissues of A. conyzoide decreased with time. For dicofol in the soil, it varied from 3.30mg · kg^-1 on 10th d to 1. 313mg · kg^-1 on 30th d. In the aerial tissues, it ranged from 2. 965mg · kg^-1 on 10th d to 1. 477mg · kg^-1 on 30th d. On the contrary, dicofol in the roots increased with time, i. e., 4. 541 mg · kg^-1 on 10th d. and 12. 734mg · kg^-1 on 30th d. The results suggested that A. conyzoides could be used to absorb dicdol residues in soil for the tea plantation.