Pb胁迫对香豌豆幼苗部分生长和生理生化指标的影响

Effect of Pb stress on some growth and physiological-biochemical indexes of Lathyrus odoratus seedlings

采用盆栽方法研究了土壤中0(CK)、150、300、450和600 mg.kg-1铅(Pb)对香豌豆(Lathyrus odoratus Linn.)幼苗部分生长和生理生化指标的影响。结果表明:随Pb质量浓度的提高,香豌豆株高、根长以及地上和地下部分的干质量均呈逐渐下降趋势,耐性指数呈低质量浓度条件下升高、高质量浓度条件下降低的趋势;其中,在450和600 mg.kg-1Pb胁迫条件下,香豌豆幼苗根长以及地上部分和地下部分的干质量均显著低于对照(P<0.05),说明植株的生长受到明显抑制。随Pb质量浓度的提高,幼苗地上和地下部分的相对电导率和SOD活性呈逐渐增加的趋势,其中,在600 mg.kg-1Pb胁迫条件下相对电导率和SOD活性均最高。各处理组地上和地下部分的脯氨酸(Pro)含量呈低质量浓度条件下降低、高质量浓度条件下增加的趋势,而POD活性、谷胱甘肽(GSH)和抗坏血酸(AsA)含量则呈现低质量浓度条件下增加、高质量浓度条件下降低的趋势。其中,在300 mg.kg-1Pb胁迫条件下Pro含量最低且显著低于对照;在450 mg.kg-1Pb胁迫条件下POD活性最高;在150 mg.kg-1Pb胁迫条下GSH含量最高,且各处理组间POD活性和GSH含量有显著差异;但各处理组AsA含量均与对照无显著差异。研究结果表明:香豌豆对Pb胁迫具有一定的耐性,可用于轻度Pb污染环境的修复。

Effects of 0（CK）, 150, 300,450 and 600 mg·kg-1 lead （Pb） in soil on some growth and physiological-biochemical indexes of Lathyrus odoratus Linn. seedlings were studied by pot culture method. The results show that with rising of Pb mass concentration, seedling height, root length, dry weights of above- and under-ground parts of L. odoratus all appear the gradually decreasing trend, tolerance index appears the trend of increasing under low mass concentration condition and decreasing under high mass concentration condition. In which, under 450 and 600 mg·kg-1 Pb stress condition, root length, dry weights of above- and under-ground parts all are significantly lower than those of the control （P〈0.05）, meaning that the growth of L. odoratus is inhibited obviously. As rising of Pb mass concentration, relative electric conductivity and SOD activity of above- and under-ground parts appear the gradually increasing trend, in which, relative electric conductivity and SOD activity of seedlings all are the highest under 600 mg·kg-1 Pb stress condition. Proline （Pro） content of above- and under-ground parts of all treatment groups appears the trend of decreasing under low mass concentration condition and increasing under high mass concentration condition, while POD activity, contents of GSH and AsA appear the trend of increasing under low mass concentration condition and decreasing under high mass concentration condition. In which, Pro content under 300 mg·kg-1 Pb stress condition is the lowest with significant difference to that of the control, POD activity under 450 mg·kg-1 Pb stress condition is the highest and GSH content under 150 mg·kg-1 Pb stress condition is the highest, and there are significant differences in POD activity and GSH content among different Pb treatment groups. But there is no significant difference in AsA content between different Pb treatment groups and the control. It is suggested that L. odoratus has a certain tolerance to Pb stress, it can be used for repairing the environment polluted slightly by Pb.