甜菜不同品种光合生产能力的研究

通过田间小区试验，对两个甜菜品种在光能和土壤氮素营养资源的利用特点等方面进行了研究，结果表明，不同甜菜品种的光合生产能力差异显著，并表现在干物质积累进程和积累量，辐射量对群体生物闰量及不同光照强度对个体净光合速率的效应等方面，对氮肥的反映，不同品种间也存在多样性，低光合力的品种对氮比较敏感，少量施氮就能明显提高群体的生物产量，而高光合力的品种则需在较高的氮素水平下才能达到显著水平，在个体光合强度上，无论入射的光照强度怎样变化，低光合生产力的品种均可通过施氮肥得到明显的改善，而高光合生产力的品种对氮肥几乎没有反映，通过减少枯叶比率，增加有效光合器官的数量，提高光合叶片的“比叶N含量”，促进对自然光的截获，进而增强光合生产能力，这是高光合生产能力品种的基本特点。

Studies on the photo-productivity of different sugarbeet varieties

In order to investigate the ability of sugarbeet crop in exploiting the light energy and soil N resource,two sugarbeet varieties were used in the field trial,the results indicated:the deference of photo-productivity between the varieties was significant,which was showed in the aspect of procedure and amount of dry matter accumulation,the effect of radiation on bio-mass of beet crown,the influence of light intensity on net photosynthetic rate and so on.The reaction of sugarbeet varieties to N fertilization were also versatile,the variety of lower photo-productivity was sensitive to N applying rate,which was showed both in bio-mass and in net photosynthetic rate.On the contrary,the variety of higher photo-productivity had a lower sensitivity in the above the essential factors of the sugarbeet variety which has higher photo-productivity.