2个大豆品种不同发育阶段对镉胁迫的生理响应及耐镉差异研究

为了探讨镉(Cd)胁迫对不同大豆品种不同发育阶段的生理生态响应及其耐镉差异性，采用盆栽试验方法，研究了镉胁迫下‘五月王’和‘日本青’2个大豆品系幼苗期、花荚早期、花荚晚期植株生长及叶片叶绿素含量、超氧化物歧化酶(SOD)活性、过氧化物酶(POD)活性和丙二醛(MDA)含量的变化动态，并对它们的耐镉性进行了比较分析。结果表明：当Cd浓度为0.50 mg/kg时，对‘五月王’植株高度的促进作用最大，而对‘日本青’植株高度促进作用最大的Cd浓度为0.25 mg/kg。Cd胁迫对‘五月王’幼苗期、花荚早期、晚期叶绿素合成刺激效应最显著的Cd浓度分别为0.25 mg/kg、0.50 mg/kg、2.50 mg/kg；Cd胁迫对‘日本青’幼苗期、花荚早期、晚期叶绿素合成刺激效应最显著的Cd浓度均为0.25 mg/kg。在花荚早期，当外源Cd浓度≤0.50 mg/kg水平时，随着Cd浓度的增加，‘日本青’植株SOD活性缓慢上升，但‘五月王’植株SOD活性基本上没有变化；使‘五月王’和‘日本青’植株SOD活性增加最明显的Cd胁迫浓度分别为2.50、1.00 mg/kg。这表明‘日本青’不同时期植株对Cd的敏感性高于‘五月王’。

Research on Response of Physiological-Ecological and Resistance Difference to Cadmium of Two Soybean Varieties During Different Developmental Stages under Cd Stress

For the sake of discussing the physiological and ecological response and resistance difference to cadmium (Cd) of plants in different developmental stages under the intimidate of Cd, a pot experiment was conducted to study the dynamics of seedling growth and chlorophyll contents, SOD (superoxide dismutase) activities, POD (Peroxidase) activities and MDA (malondialdehyde) contents in leaves of Glycine max (Wu Yue Wang and Ri Ben Qing) under the stress of Cd in seedling stage, flowering-poding early stage and flowering-poding advanced stage, and comparative analysis the resistance of the two varieties to cadmium. The results showed that the most significant stimulating effects of Cd concentrations on the heights of Wu Yue Wang and Ri Ben Qing were 0.50 mg/kg and 0.25 mg/kg, respectively. Those on chlorophyll contents of Wu Yue Wang at seedling stage, early flowering-poding stage and flowering-poding advanced stage were 0.25 mg/kg, 0.50 mg/kg, 2.50 mg/kg, respectively. But, those on chlorophyll contents of Ri Ben Qing at different stages were all 0.25 mg/kg. At early flowering-poding stage, below 0.50 mg/kg of Cd, SOD activity of Ri Ben Qing rose slowly with the increase of Cd concentrations added in soil, but SOD activity of Wu Yue Wang basically changed quite slightly. The most significant stimulating effects of Cd concentrations on SOD activity of Wu Yue Wang and Ri Ben Qing at early flowering-poding stage were 2.50 mg/kg and 1.00 mg/kg, respectively. All the facts above showed that Ri Ben Qing was more sensitive to Cd stress at different developmental Stages than Wu Yue Wang.