硒对高温胁迫下萝卜幼苗叶绿素含量和酶活性的影响

为了研究高温胁迫下硒对萝卜幼苗活性氧代谢保护酶系统的影响,采用盆栽试验,将萝卜品种优白1号和白玉春栽培于不同含硒量的基质中,待萝卜幼苗长至5~6 cm时,移入人工气候室进行高温胁迫处理(38℃,12 h)。结果显示,施硒提高了叶片总叶绿素含量。当施硒量为0.6 mg/kg时,优白1号、白玉春叶片的过氧化物酶(POD)活性分别提高了8.4%和4.3%,谷胱甘肽过氧化物酶(GPX)活性分别提高了5.8倍和1.6倍。超氧化物歧化酶(SOD)活性却降低了18.4%和20.6%(0.9 mg/kg)。由此可见,一定量的硒可以缓解高温胁迫对萝卜叶片的伤害,提高其耐热性。

Effect of Se to Chorophyll Content and Enzyme Activity of Radish Seedlings under the High Temperature

The research aimed to study the effects of high temperature damage on the activated oxygen metabolism protective enzyme system.Two cultivars(Youbai1 and Baiyuchun) of radish(Raphanus sativus L.) were planted in culture media with different selemium(Se) concentrations.When the radish seedlings growed to 5-6cm,the plants were transferred into climatic room and exposed to high temperature strss(38℃,12h).Then the leaves were harvested for measurement of chlorophyll and malondialdehyde(MDA) contents and activities of three antioxidant enzymes.The results indicate: selenium improved the content of total chorophyll,and in-cresed the activities of peroxidase(POD) and glutathione peroxidase up to 8.4%,4.3% and 5.8,1.6 times respectively when selenium was 0.6mg/kg.In addition,selenium also raised the MDA content of leaves by 4.17% and 5.1%,whereas the activities of superoxide dismutase(SOD) decreased about 18.4% and 20.6%(0.9mg/kg).So the treatments with selenium could relieve the damage to the radish seedlings,and improved the tolerance to high temperature stress.