外源稀土对水稻伤流组分的影响

应用微区试验和伤流测定法研究了外源稀土对水稻根系合成氨基酸和激素的效应,以及对伤流中无机营养离子的影响。结果表明,在本试验条件下,土施低浓度稀土能促进根系合成,显著增加氨基酸总量和激素在伤流中的含量,提高营养离子的吸收;但高浓度稀土却有着明显的抑制效应。应用数学模拟的方法计算出稀土抑制氨基酸合成的半效应值(或50值)约为350～500mg/kg。稀土提高了伤流液中钙的含量,而对磷、钾的含量起抑制效应。

Effect of rare earth on composition of bleeding sap of rice

An micro-plot experiment was conducted to study the effect of rare earth on the bleeding composition of rice. The results showed that the vitality and synthesis of root and contents of amino acids and plant hormones, as well as contents of plant nutrients in bleeding sap of rice were greatly increased with lower concentration of rare earth, but inhibited by higher concentration of RE. The numerical simulation of data of three kinds of amino acids in bleeding sap reveals that the results fit well in with logarithmic equation and the 50 value (semi-effect value) calculated by this equation was about 350-500 mg/kg.