镉、锌胁迫对番茄幼苗生长及脯氨酸和谷胱甘肽含量的影响

研究水培条件下,重金属镉、锌胁迫对番茄种子萌发、幼苗生长及相关生理指标的影响。结果表明:镉、锌溶液(2.000 mmol/L)能明显抑制种子的发芽势、发芽率和根的伸长,受抑制程度为根>发芽势>发芽率;镉(0.001 mmol/L~0.100 mmol/L)和锌(0.010 mmol/L~1.000 mmol/L)能够抑制番茄幼苗株高的增长和干物质的积累、降低叶绿素a、叶绿素b、叶绿素a b及叶绿素a/b值;番茄茎、叶含水量在高浓度处理(镉、锌营养液浓度分别为0.100 mmol/L和1.000 mmol/L)时明显降低;番茄根、叶中脯氨酸和谷胱甘肽含量均随镉、锌营养液浓度的提高而呈增加趋势,而可溶性糖含量只有当镉、锌营养液浓度分别为0.100 mmol/L和0.100 mmol/L、1.000 mmol/L时才上升。依据试验结果,作者讨论了重金属镉、锌对番茄幼苗根、叶中可溶性糖、脯氨酸和谷胱甘肽含量的作用。

Effects of Cadmium and Zinc Stress on Growth and Content of Proline and Glutathione (GSH) in Tomato Seedlings

A hydroponical experiment was carried out to evaluate effects of cadmium and zinc stress on the germination, growth and correlative physiological indices of seedlings in tomato. Results showed that cadmium and zinc solution (2.000 mmol/L) remarkably inhibited the sprouting potential, sprouting ratio and the root elongation.The inhibition was in the order of root elongation>sprouting potential>sprouting ratio. Cd (0.001 mmol/L-0.100 mmol/L) and Zn (0.010 mmol/L-1.000 mmol/L) could inhibit plant height and biomass accumulation and decrease the value of chlorophyll a, chlorophyll b, chlorophyll a b and chlorophyll a/b of leaves. The water content of stems and leaves of tomato declined significantly under high concentration stress (Cd and Zn concentrations in nutrient solutions were respectively (0.100 mmol/L) and 1.000 mmol/L). With increasing of Cd and Zn concentrations, contents of proline and glutathione (GSH) increased, while soluble sugar content increased only when Cd concentration was 0.100 mmol/L and Zn concentrations were 0.100 mmol/L and 1.000 mmol/L. According to the results of the experiment, the authors discuss the role of soluble sugar, proline and GSH in roots and leaves of tomato seedlings under Cd and Zn stess.