中文摘要：

采用标准偏高糖型甜研7号与标准偏丰产型甜研8号2个二倍体纯系品种及水培方法，研究了子叶期（11d）甜菜对NO3^-和NH4^＋的吸收特性以及不同NO3^-／NH4^＋比对苗期（31d）甜菜吸收特性的影响。发现了子叶期甜研7号较甜研8号对NH4^＋有较大的Vmax,有利于NH4^＋的吸收。低NH4^＋浓度比促进甜菜对N03的吸收。而且甜研7号受到的影响相对大于甜研8号。不同NO3^-／NH4^＋也影响甜菜对NH4^＋的吸收速率，2品种所受的影响并不相同。2品种遗传特性不同导致了甜研7号对NH4^＋的吸收较甜研8号敏感。高浓度NH4^＋的存在促进了甜研7号与甜研8号对NH4^＋的吸收。说明可以通过调节甜菜对NO3^-与NH4^＋的吸收与同化关系来调控甜菜的氮代谢，以提高甜菜的产量与质量。

英文摘要：

Solution culture experiments were carried out to study uptake character at cotyledon stage and the effect of NO3^- / NH4^＋ ratio on nitrate and ammonium uptake at seedling stage with two cultivars of sugar beet, including high sugary Tianyan 7 and prolific Tianyan 8. Vmax of NH4^＋ was higher in Tianyan 7 than in Tianyan 8 at cotyledon stage （Table 1 ）. It was benefit for Tianyan 7 to uptake NH4^＋ . After cultivated with different NO3^-/NH4^＋ , there was significant deviation of NO3^- uptake between Tianyan 7 and Tianyan 8 （ Fig.3 and Fig. 4）. Nitrate uptake was enhanced by optimal ammonium in nutrient solution. Tianyan 7 was more affected than Tianyan 8 （Table 2）. Ammonium uptake was also affected by NO3^- / NH4^＋ ratio in culture solution （Fig. 5 and Fig. 6）. It was enhanced by high NH4^＋ concentration in nutrient solution （Table 3）, and Tianyan 7 was more sensitive to ammonium uptake than Tianyan 8 due to the different genetic properties of two cultivars. In conclusion nitrogen metabolism can be regulated through regulating the relationship between nitrate and ammonium uptake and assimilation to increase output and quality of sugar beet.