苯达松对轮叶黑藻生理特性的影响

摘要

随着水体污染的日趋严重,水生植被特别是沉水植被的衰退和消失是世界范围内的普遍现象,为探究其退化与除草剂的相关性,采用水培试验方法,研究不同浓度苯达松对轮叶黑藻植株叶绿素含量和2种抗氧化酶活性,以及丙二醛(MDA)、可溶性蛋白(SP)及脯氨酸(Pro)含量的影响.结果表明,苯达松可以抑制轮叶黑藻叶绿素a的合成,促进叶绿素b的合成(除4.0 mg·L-1处理外),叶绿素总量随苯达松浓度增加而下降,降低了植物体光合能力;在试验浓度范围内,过氧化物酶(POD)活性先升高后降低,超氧化物歧化酶(SOD)活性在0.1,0.2,1.0 mg·L-1处理呈先升后降的趋势,而在0.5,2.0,4.0 mg·L-1处理及CK呈降低-升高-降低的趋势;处理后第10天,随着苯达松浓度的增加,轮叶黑藻体内丙二醛(MDA)含量先升后降,至0.5 mg·L-1达到最高,可溶性蛋白(SP)含量显著下降,而脯氨酸(Pro)含量显著升高.上述结果均说明苯达松影响了轮叶黑藻正常的生理代谢活动.%As the pollution of water has becoming more and more serious, the decline and disappearance of aquatic vegetation espe-cially submerged vegetation was a worldwide phenomenon. In order to explore the correlation between aquatic vegetation degradation and herbicide,the hydroponics method was used in this experiment,and the effects of different concentrations of bentazon on physio-logical characteristics of Hydrilla verticillatai were studied, including chlorophyll content, two kinds of antioxidant enzyme activities, and the content of malondialdehyde(MDA),soluble protein(SP)proline(Pro)in the plant.The results showed that the biosynthesis of chlorophyll a were inhibited,while the synthesis of chlorophyll b (except 4.0 mg·L-1treatment)were promoted by bentazon.Following with the increasing of bentazon concentration, the total chlorophyll content decreased, indicating the photosynthetic capacity was re-duced.In the experiment,the activity of peroxidase(POD)at all the treatments,and the activity of superoxide dismutase(SOD)at 0.1, 0.2 mg·L-1treatments were showing the same trend that first increased and then decreased,while the activity of superoxide dismutase (SOD)at 0.5,2,4 mg·L-1treatment and CK showed a trend of decreasing-increasing-decreasing.Following with the increasing of bentazon concentration, the content of malondialdehyde increased first and then decreased, the soluble protein content decreased significantly,while the proline content increased significantly.