In vivo activity of cholinesterase （ChE） in Daphnia magna was measured at different time points during 21-day exposure to triazophos and chlorpyrifos ranging from 0.05 to 2.50 μg/L and 0.01 to 2.00 μg/L, respectiv...In vivo activity of cholinesterase （ChE） in Daphnia magna was measured at different time points during 21-day exposure to triazophos and chlorpyrifos ranging from 0.05 to 2.50 μg/L and 0.01 to 2.00 μg/L, respectively. For exposure to triazophos, ChE was induced up to 176.5% at 1.5 μg/L and day 10 when measured by acetylthiocholine （ATCh）, whereas it was induced up to 174.2% at 0.5 μg/L and day 10 when measured by butyrylthiocholine （BTCb）. For exposure to chlorpyrifos, ChE was induced up to 134.0% and 160.5% when measured by ATCh and BTCh, respectively, with both maximal inductions detected at 0.1 Ixg/L and day 8. Obvious induction in terms of ChE activity was also detected in daphnia removed from exposures 24 hr after their birth and kept in a recovery culture for 21 days. Results indicated that the enzyme displayed symptoms of hormesis, a characteristic featured by conversion from low-dose stimulation to high-dose inhibition. In spite of that, no promotion in terms of reproduction rate and body size was detected at any tested concentrations regardless of whether the daphnia were collected at end of the 21-day exposure or at end of a 21-day recovery culture. This suggested that induction of ChE caused by anticholinesterases had nothing to do with the prosperity of the daphnia population.展开更多
以亳菊为试材,研究了不同培养基营养成分和蔗糖浓度对其试管苗离体保存的影响,并对再生后代的遗传稳定性进行了初步形态学比较。试验结果表明：在（23±2）℃、2000～3000 lx 光照强度、12 h. d -1的光照培养条件下,MS 培养基中添加...以亳菊为试材,研究了不同培养基营养成分和蔗糖浓度对其试管苗离体保存的影响,并对再生后代的遗传稳定性进行了初步形态学比较。试验结果表明：在（23±2）℃、2000～3000 lx 光照强度、12 h. d -1的光照培养条件下,MS 培养基中添加15 g. L -1蔗糖,或者1/2 MS 培养基中添加15 g. L -1蔗糖均能使亳菊连续保存365 d 以上,并且保持有较高的成活率,分别为88.9%和97.8%。保存365 d 的试管苗在 MS 培养基上均长势良好,能恢复正常生长,再生后代形态上与对照组中试管苗无差异,保持了良好的遗传稳定性。展开更多
基金supported by the Department of Education of Zhejiang Province,China (Natural Science Project,No. 20070138)the Zhejiang Provincial Natural Science Foundation of China (No. Y307448)
文摘In vivo activity of cholinesterase （ChE） in Daphnia magna was measured at different time points during 21-day exposure to triazophos and chlorpyrifos ranging from 0.05 to 2.50 μg/L and 0.01 to 2.00 μg/L, respectively. For exposure to triazophos, ChE was induced up to 176.5% at 1.5 μg/L and day 10 when measured by acetylthiocholine （ATCh）, whereas it was induced up to 174.2% at 0.5 μg/L and day 10 when measured by butyrylthiocholine （BTCb）. For exposure to chlorpyrifos, ChE was induced up to 134.0% and 160.5% when measured by ATCh and BTCh, respectively, with both maximal inductions detected at 0.1 Ixg/L and day 8. Obvious induction in terms of ChE activity was also detected in daphnia removed from exposures 24 hr after their birth and kept in a recovery culture for 21 days. Results indicated that the enzyme displayed symptoms of hormesis, a characteristic featured by conversion from low-dose stimulation to high-dose inhibition. In spite of that, no promotion in terms of reproduction rate and body size was detected at any tested concentrations regardless of whether the daphnia were collected at end of the 21-day exposure or at end of a 21-day recovery culture. This suggested that induction of ChE caused by anticholinesterases had nothing to do with the prosperity of the daphnia population.
文摘以亳菊为试材,研究了不同培养基营养成分和蔗糖浓度对其试管苗离体保存的影响,并对再生后代的遗传稳定性进行了初步形态学比较。试验结果表明：在（23±2）℃、2000～3000 lx 光照强度、12 h. d -1的光照培养条件下,MS 培养基中添加15 g. L -1蔗糖,或者1/2 MS 培养基中添加15 g. L -1蔗糖均能使亳菊连续保存365 d 以上,并且保持有较高的成活率,分别为88.9%和97.8%。保存365 d 的试管苗在 MS 培养基上均长势良好,能恢复正常生长,再生后代形态上与对照组中试管苗无差异,保持了良好的遗传稳定性。
