镉和UV-B辐射增强复合胁迫对冬小麦幼苗生长和生理的影响

Combined Effects of Cd and Enhanced UV-B Radiation on Growth and Physiology of Winter Wheat Seedling

通过种子萌发和盆栽试验研究了镉(Cd)与UV-B辐射增强单独和复合胁迫对冬小麦幼苗生长和生理的影响,结果表明:(1)Cd与UV-B单独或复合胁迫对冬小麦种子萌发率没有显著影响,但明显抑制冬小麦幼苗的生长,复合胁迫的抑制效应明显大于单一胁迫;(2)UV-B辐射增强导致冬小麦叶片的叶绿素含量显著或极显著下降,类黄酮含量极显著增加,Cd胁迫没有显著影响,且复合Cd胁迫后不加剧UV-B辐射对冬小麦叶片叶绿素和类黄酮含量的影响;(3)Cd与UV-B单独胁迫均导致冬小麦叶片的细胞膜透性极显著增大,Cd胁迫导致冬小麦叶片的MDA含量显著增加,且UV-B辐射加剧Cd胁迫对冬小麦叶片MDA含量的影响;(4)Cd+UV-B复合胁迫冬小麦植株地上部的Cd含量显著高于Cd单独胁迫。可见,Cd和UV-B辐射增强复合胁迫对冬小麦生长和生理的影响存在协同效应。

The effects of the individual and combined cadmium（Cd）,enhanced UV-B radiation on the growth and physiology of winter wheat were studied with seeds germination and pot experiments.Results showed that：（1）No significant effect of the Cd and enhanced UVB radiation individual or combined stress on seeds germination rate of winter wheat was observed.The growth of winter wheat seedlings was inhibited significantly.The inhibitory effects with the combined stress were significantly greater than with a single stress.（2）The chlorophyll contents in winter wheat leaves decreased significantly and the flavonoid contents increased significantly under enhanced UV-B radiation.The effects of Cd stress were not obvious.The effects of enhanced UV-B radiation on chlorophyll and flavonoid contents did not intensify with the combined Cd stress.（3）The cell membrane permeability of winter wheat leaves increased significantly with individual Cd or enhanced UV-B radiation stresses.The MDA contents increased significantly with Cd stress.The effects of Cd stress on the MDA contents in winter wheat leaves were promoted by the combined enhanced UV-B radiation.（4）The contents of Cd in winter wheat shoots under Cd and enhanced UV-B radiation combined stresses were significantly higher than that under Cd stress.These results indicate that there were additive effects of Cd and enhanced UV-B radiation combined stress on the growth and physiology of winter wheat.