追氮时期对小麦光合作用、^(14)C同化物运转分配和硝酸还原酶活性的影响

The effects of nitrogen topdressing stage on photosynthesis, translocation and distribution of (14)~C assimilate and NR activity of wheat

采用盆栽和水泥池栽研究了追氮时期对小麦光合作用、14 C同化物运转分配和硝酸还原酶 ( NR)活性的影响。结果表明 ,拔节 (雌雄蕊原基形成 )期较起身 (二棱 )期追施氮肥 ,显著提高了小麦开花后的旗叶叶绿素含量和单叶光合速率 ;灌浆期旗叶 14 C同化物向籽粒转移比例显著提高 ,而在营养器官的滞留比例显著降低 ;旗叶和根系中硝酸还原酶 ( NR)活性亦显著提高。小麦穗粒数、粒重和产量增加 。

The effects of nitrogen topdressing stage on photosynthesis,translocation and distribution of 14 C assimilate and NR activity in wheat were studied by combination experiments of pot culture and trough culture.The results showed that,compared with topdressing nitrogen fertilizer at double ridged stage,topdressing at jointing stage improved the chlorophyll content and photosynthetic rate of flag leaf.At filling stage,the proportion of 14 C assimilation translocated to grain remarkablely improved,while that remained at vegetative organs declined.The NR activities of flag leaf and root were increased significantly.As a result,the grain number per spike,the grain weight,the yield,and the content of protein improved remarkablely.