模拟酸雨对3种本地草本植物的胁迫效应

研究了不同pH值的模拟酸雨对3种本地草本植物华泽兰（Eupatorium chinense Linn.）、鸡矢藤Paederia scandens (Lour.) Merr.]和蟛蜞菊Wedelia chinensis （Osbeck.）Merr.]的光合生理生态的胁迫效应. 结果表明，重度酸雨（pH 2.5）对3种草本植物均造成伤害，其中华泽兰和鸡矢藤叶片受害明显，受害叶面积约5%~10%左右，而蟛蜞菊叶片受害最轻，受害叶面积＜5%. 随着酸雨pH值的降低，华泽兰叶片叶绿素（Chl）含量和净光合速率（Pn）逐渐降低；鸡矢藤Chl没有显著性变化，但其Pn受到抑制；蟛蜞菊Chl和Pn则呈上升的趋势. 酸雨胁迫下，3种草本植物超氧化物歧化酶（SOD）和过氧化物酶（POD）活性均有不同程度的提高. 上述结果表明，华泽兰和鸡矢藤受酸雨胁迫的影响较蟛蜞菊更大，蟛蜞菊是一种抗酸雨胁迫较强的本地草本植物.

Stress Effects of Simulated Acid Rain on Three Native Herbaceous Plants

This study aims to test the stress effect of simulated acid rain (pH 2.5, 4.5, 5.6)on the photo-physiological characteristics of three native herbaceous plants (Eupatorium chinense Linn., Paederia scandens (Lour.) Merr. and Wedelia chinensis （Osbeck.）Merr.). The results indicated that leaves of the three herbaceous plants showed injury under severe acid rain stress (pH 2.5). Leaves of E. chinense and P. scandens were damaged obviously and the damage area was between 5% and 10%, while that of W. chinensis was damaged slightly and the damage area was lower than 5%. Meanwhile, the three herbaceous plants showed different photosynthetic responses to simulated acid rain. With the decreasing pH, the chlorophyll (Chl) content and net photosynthetic rate (Pn) of E. chinense were both reduced, P. scandens had no significant difference in the Chl content, but its Pn was inhibited, while the Chl content and Pn of W. chinensis both had a trend of rising. Under severe acid rain stress, the activity of superoxide dismutase (SOD) and peroxidase (POD) increased in all three plants to varying degrees, which showed some resistance to acid rain. The present results indicated that W. chinensis showed a strong resistant to the acid rain than the other two herbaceous plants.