外源褪黑素处理对镉胁迫下水稻种子萌发的影响

为探讨外源褪黑素对Cd胁迫下植物生长发育的影响，采用室内培养实验研究外源褪黑素对Cd胁迫下水稻种子萌发及相关生理指标的影响。结果表明：外源褪黑素对Cd胁迫下水稻种子萌发具有一定的促进作用，褪黑素施用可提高水稻种子的发芽率和发芽势，促进水稻幼根和幼芽的生长，当Cd浓度为100μmol·L-1时，添加100μmol·L-1褪黑素使得水稻根系活力和总根长分别比对照处理提高15.2%和133.7%；外源褪黑素能显著降低Cd胁迫下水稻幼芽的MDA含量，提高水稻体内的POD、SOD和CAT的活性，当Cd浓度为100μmol·L-1时，添加10~1000μmol·L-1褪黑素会使水稻幼芽MDA含量比对照处理降低8.2%~16.0%，POD、SOD和CAT的活性分别比对照处理提高21.3%~45.5%、24.2%~32.2%和77.8%~145.8%。褪黑素可以有效地缓解Cd对水稻的毒害作用。

Effects of exogenous melatonin on germination of rice seeds under Cd stresses

Here the effects of exogenous melatonin(MT)on seed germination and physiological indexes of rice under Cd stresses were in-vestigated. Additions of exogenous MT had a positive effect on seed germination and root growth of rice under Cd stresses. At 100μmol·L-1 of Cd concentration, addition of 10μmol·L-1 MT increased total root length of rice by 103.2%, and applying 100μmol·L-1 exogenous MT promoted rice root activity and total root length by 15.2%and 133.7%, respectively, as compared with the control. At 100μmol Cd·L-1, ad-ditions of 10~1000μmol·L-1 exogenous MT significantly decreased MDA by 8.2%~16.0%, but increased activities of POD, SOD, and CAT by 21.3%~45.5%, 24.2%~32.2%and 77.8%~145.8%, respectively, in comparison with the control treatment. These results suggest that ap-plication of exogenous melatonin could effectively alleviate the toxic effects of Cd on rice.