摘要： 以黄瓜（Cucumis sativusL.）幼苗为材料，研究UV_B辐射对黄瓜幼苗生长和光合作用的影响。结果表明：UV_B辐射对黄瓜幼苗株高的抑制作用非常明显。低剂量UV_B辐射明显促进黄瓜幼苗根的生长，促进黄瓜幼苗根系活力，有利于黄瓜叶绿素的形成。但是高剂量的UV_B辐射抑制黄瓜幼苗根系活力，对黄瓜叶绿素的破坏严重并导致黄瓜幼苗光合速率下降。低剂量UV_B处理黄瓜幼苗的SOD和POD含量均显著高于对照，而高剂量UV_B处理黄瓜幼苗的SOD含量均明显低于对照，但其POD含量却显著高于对照。说明适当增加少量UV_B辐射对培育黄瓜壮苗有利。

关键词: UV-B辐射, 黄瓜幼苗, 叶绿素, 根系活力, 光合作用

Abstract: The effect of enhanced UV_B radiation on the growth and photosynthesis of cucumber (Cucumis sativus L.) seedlings was studied.The results showed that the seedling height was significantly inhibited by the UV_B radiation.The root growth and root activity of cucumber seedlings,the chlorophyll synthesis and photosynthesis were promoted by the UV_B radiation at low dosage.But high dosage of UV_B radiation inhibited the roots activity,and caused great damage of chlorophyll and decrease in photosynthetic rate (Pn).The content of SOD and POD of seedlings was higher than that of the control at low dosage of UV_B radiation.However,the content of seedling SOD was lower than that of the control but the content of seedling POD was higher than that of the control at high dosage of UV_B radiation.It suggested that the strong seedlings were facilitated by low dosage UV_B radiation.

Key words: UV_B radiation, Cucumber seedlings, Chlorophyll, Root activity, Photosynthesis

中图分类号: 

• S663.4