N对叶菜型甘薯硝酸盐积累及品质的影响

研究5、10、20、40mmol·L-14个N浓度对叶菜型甘薯鲜嫩茎叶的硝酸盐含量、硝酸还原酶(NR)活性、可溶性蛋白及总糖含量的影响.结果表明:随着N含量的增加,植株体内硝酸盐含量呈线性增加,随处理时间延长,高N含量下硝酸盐积累持续增加,但在较低含量下硝酸盐积累在施N后6-8d达到极值后有所下降;NR活性随N含量增加显著提高;N含量与总糖含量呈负相关,N含量高不利于总糖积累;N含量提高,植株可溶性蛋白含量也有所提高,但效果不明显.

Effects of nitrogen on the nitrate accumulation of vine-vegetable sweetpotato and its quality

Effects of four levels of nitrogen concentration, 5, 10, 20 and 40 mm ol·L~-1 on the nitrate content, nitrate reductase ( NR ) activity, sol uble protein and total sugar content in vine-vegetable sweetpotato were studied. Wi th the increase of nitrogen content, the nitrate content in plants appeared in l inear increase. With the lengthening of treatment duration and under the conditi on of high nitrogen content, the nitrate accumulation kept on increasing. But un der the condition of low nitrogen content, the nitrate accumulation increased fo r 6 to 8 days after nitrogen application and reached an extreme value, followed by the decrease. The nitrate reductase activity increased significantly along wi th the increase of nitrogen. There is a negative correlation between nitrogen co ntent and total sugar content, so the high nitrogen content was unfavourable for the total sugar accumulation. The increase of nitrogen content caused the insig nificant increase of soluble protein in plants.