根外施氮对热胁迫下小麦叶片光合特性的影响

Effects of exogenous nitrogen nutrition of roots on photosynthetic characteristics of leaves in wheat under heat stress

研究了38℃热胁迫下用外源氮素处理的小麦叶片中光合作用部分指标的变化,结果表明:在适度的热胁迫过程中,低浓度氮素营养处理的小麦叶片中叶绿素及可溶性蛋白含量、Fv/Fm及ФPSⅡ、表观量子效率稍微下降,而NPQ及光饱和速率有上升的趋势;较高浓度氮素营养的小麦叶片中叶绿素及可溶性蛋白含量、表观量子效率及光饱和速率明显增加,NPQ降低,Fv/Fm及ФPSⅡ有升高的趋势。说明热胁迫条件下,外施氮素营养可以提高小麦叶片的光合能力,缓解热胁迫造成的光合损伤。

The changes of photosynthetic parameters in the leaves of wheat treated by exogenous nitrogen were studied under 38℃ heat-stress. The results showed： under the condition of moderate heatstress, the contents of chlorophyll and soluble protein, Fv/Fm,ФPS1 and apparent quantum yields in the leaves were slightly reduced, and NPQ and photosynthetic rate of light-saturation were increased when the plants were treated by low-concentration nitrogen; however, the contents of chlorophyll and soluble protein, apparent quantum yields, photosynthetic rate of lightrsaturation,Fv/Fm and ФPS1 were enhanced, and NPQ was reduced when the plants were treated by high-concentration nitrogen. It is concluded that applying exogenous nitrogen nutrition can improve the foliar photosynthesis ability of wheat and alleviate photosynthetic damage by heat stress.