不同氮素水平条件下大白菜不同品种对硝酸盐富集力差异的研究

选用5个对硝酸盐富集力不同的大白菜品种,栽培在不同氮素浓度梯度下的营养液中。结果表明,硝酸盐富集力高的品种随着氮素质量浓度的提高,硝酸盐含量明显增加,在氮素水平240 mg/L条件下,“绿原5号”硝酸盐含量达到220 4 mg/L;硝酸盐富集力低的品种随着氮素浓度的提高,其硝酸盐含量增加的幅度较小,氮素水平240 mg/L条件下,“太原二青”为1 201 mg/L,“秋宝”为968 mg/L。亚硝酸盐的含量与氮素浓度的关系不大。通过对硝酸还原酶和氮素吸收力的分析,硝酸盐富集力低的机制有2种:一种是硝酸还原酶活性高、体内硝酸盐的还原速度快,另一种类是植株对氮素的吸收能力较弱。

Differences of Nitrate Accumulative Capability of Different Chinese Cabbage Genotypes Planted in Different Nitrogen Concentration Solution

5 varieties of Chinese cabbage with different nitrate accumulative capability were cultivated in different nitrogen concentration solutions. The results showed that nitrate content of the varieties with higher nitrate accumulative capability obviously increased with the improvement of solution nitrate content.While the result was the opposite to the varieties with lower nitrate accumulative capability.Nitrate content of Lvyuan5 was 2 204 mg/L when nitrate content of the solution was 240 mg/L.That of Taiyuanerqing was 1 201 mg/L,and that of Qiubao was 968 mg/L.By analyzing the relationship of nitrate reductase activities and nitrogen absorbency capabilities,we concluded that there were two mechanisms about lower nitrate accumulative capability.One was that higher nitrate reductase activity led to faster deoxidization of nitrate.The other was lower nitrogen absorption capability.