铜胁迫对甜菜幼苗生长和光合特性的影响

以甜菜品种KWS3418为实验材料，研究了铜胁迫对甜菜幼苗生长及光合作用特性的影响．结果表明：当Cu2＋≤250μmol·L-1时，甜菜幼苗生长良好，与对照（0．3μmol·L-1）相比，各生长指标没有显著差异．但是，随着Cu2＋浓度的增加（Cu2＋〉250μmol·L-1），甜菜幼苗生长受到显著抑制，其单株干、鲜重和叶面积均显著下降．Cu2＋为250μmol·L-1时，净光合速率（pn）、气孔导度（Gs）与叶绿索含量显著低于对照组，随着Cu2＋浓度的增加，净光合速率（Pn）、气孔导度（Gs）与叶绿素含量急剧下降．这些结果表明，甜菜有一定的耐铜性，但是高铜处理可能通过引起叶绿素含量和气孔导度下降来抑制光合作用进而抑制生长．

EFFECTS OF Cu2+ STRESS ON GROWTH AND PHOTOSYNTHESIS OF BETA VULGARIS

In this study, Beta vulgaris L. cv. KWS3418 was used to examine the effect of Cu2 ~ concentration on growth and photosynthetic characteristics. Results showed that when the concentration of Cu2＋≤ 250μmol·L-1, plants grown well and no significant difference was detected between control （0.3 μmol·L-1） and copper - treated plants. However, with the increase of Cu2＋ concentration （Cu2＋ 〉 250μmol·L-1 ）, the growth of plants such as leaf area, leaf fresh and dry weight, fresh and dry weight per plant all decreased significantly. Moreover, net photosynthetic rate and chlorophyll content were lower than those of control. These findings suggseted that red beet can endure certain copper stress, but under higher copper stress the seedings were seriously damaged possibly via decrease of chlorophyll and stomata conductivity which led to the inhibition of photosynthesis and growth.