【摘要】 采用不同质量比的氮源、氮胁迫和不同钼质量浓度的营养液栽培方法,探讨其对蕹菜(IpomoeaaquaticaForsk)的生长和体内硝酸还原酶(NR)活性的影响,揭示蕹菜体内硝酸盐积累的规律。结果表明:以NO3-为单一氮源不仅会导致蕹菜NO3-严重积累,也会使产量偏低;而以NH4+为单一氮源,蕹菜则不能正常生长;蕹菜在收获前10 d停止供氮可以降低蔬菜中NO3-含量;随着钼质量浓度的增加硝酸还原酶活性呈上升趋势,但当钼质量浓度>0.378mgL时,硝酸还原酶活性则会降低,只有适当的钼浓度才可以降低蕹菜的NO3-含量。更多还原

【Abstract】 In order to study the regularity of nitrate accumulation and the activity of nitrate reductase in swamp cabbage, hydroponics experiments were conducted with different ratios of NO3--N to NH4+-N and molybdenum levels respectively. The results showed that applying NO3- as the unique N source resulted in serious nitrate accumulation and lower crop yield. The nitrate content in swamp cabbage was decreased when N supply was stopped ten days before harvest. Supply of appropriate concentration of molybdenum could also decrease the nitrate content in the crop.更多还原