~(14)C示踪研究结果表明:小麦不同生育期的光合速率不同,苗期较低,为10.00mgCO_2dm~(-2)h~(-1)左右,拔节后光合速率急剧加快,至抽穗期达最高值44.53—48.80mgCO_2dm~(-2)h~(-1)。标记期问呼吸速率的变化趋势与此相同。抽穗前,茎叶为光合产物分配的主要去向,以后穗部分配比率很快增加,根系始终占有相当分配比率。施氮方式对拔节期和抽健期小麦的光合速率有明显影响。 The results of ~ (14) C tracer showed that the photosynthetic rate of wheat at different growth stages was different, and the seedling stage was lower at about 10.00mgCO_2dm -2 h -1. After photosynthesis, the photosynthetic rate accelerated sharply after heading, The maximum reached 44.53-48.80mgCO_2dm ~ (-2) h ~ (-1). The changing trend of respiration rate during the labeling period is the same. Before heading, stems and leaves were the main destination for the distribution of photosynthetic products. Afterwards, the proportion of spike parts increased rapidly, and the root system always occupied a considerable distribution ratio. Nitrogen application rates had significant effects on photosynthetic rate of wheat at jointing and pumping stages.