蚕豆幼苗对NaCl和NaHCO3胁迫的生理响应

采用不同浓度的NaCl和NaHCO3处理蚕豆幼苗,处理7 d后分别测定蚕豆幼苗鲜重、蚕豆叶片MDA和脯氨酸含量、蚕豆叶片抗氧化酶活性。结果显示,随NaCl和NaHCO3胁迫浓度的增加,蚕豆幼苗鲜重先显著增加后显著下降(P<0.05);叶中MDA和脯氨酸含量显著上升(P<0.05),NaCl低于NaHCO3的上升幅度;超氧化物歧化酶(SOD)活性先显著增加(P<0.05)然后下降;过氧化物酶(POD)活性在NaCl胁迫下显著升高(P<0.05),NaHCO3胁迫下先升高后显著降低(P<0.05);过氧化氢酶(CAT)活性显著增加(P<0.05)。蚕豆具有一定程度的抗盐碱性,碱胁迫大于同浓度盐胁迫的伤害。

Physiological responses of Vicia faba L. seedlings under NaCl and NaHCO3 stress

Vicia faba L. seedlings were treated with different concentrations of NaCl and NaHCO₃ for 7 days, and the fresh weight, malondialdehyde (MDA) content, free proline content, and the activities of antioxidant enzymes were determined. The results were as follows. With the increase of NaCl and NaHCO₃ concentrations, fresh weight of Vicia faba L. seedlings first increased significantly and then declined, MDA and free proline contents increased significantly, and the increase extent under NaCl stress was lower than under NaHCO₃. The activity of superoxide dismutase ( SOD) first increased significantly and then declined. The activity of peroxidase ( POD) increased significantly under NaCl stress, and first rose and then decreased significantly under NaHCO₃ stress. The activity of catalase (CAT) increased significantly. In conclusion, Vicia faba L. could resist salt and alkali stress to a certain degree. The responses of Vicia faba L. to alkali stress were more obvious than that to salt stress on average.