文献类型： 外文期刊

作者： Lin, Xian Yong ¹ ; Liu, Xiao Xia ¹ ; Zhang, Ying Peng ² ; Zhou, Yuan Qing ¹ ; Hu, Yan ¹ ; Chen, Qiu Hui ¹ ; Zhang, Yon ¹ ;

作者机构： 1.Zhejiang Univ, Coll Environm & Resource Sci, MOE Key Lab Environm Remediat & Ecosyst Hlth, Hangzhou 310058, Zhejiang, Peoples R China

2.Shandong Acad Agr Sci, Soil & Fertilizer Inst, Jinan 250100, Peoples R China

关键词： nitrate;patterns of nitrogen supply;vitamin C;oxalate

期刊名称：JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE （ 影响因子：3.638； 五年影响因子：3.802 ）

ISSN： 0022-5142

年卷期： 2014 年 94 卷 5 期

页码：

收录情况： SCI

摘要： BACKGROUND Quality-associated problems, such as excessive in planta accumulation of oxalate, often arise in soillessly cultivated spinach (Spinacia oleracea). Maintaining a higher level of ammonium (NH4+) compared to nitrate (NO3-) during the growth period can effectively decrease the oxalate content in hydroponically cultivated vegetables. However, long-term exposure to high concentrations of NH4+ induces toxicity in plants, and thus decreases the biomass production. Short-term application of NH4+ before harvesting in soilless cultivation may provide an alternative strategy to decrease oxalate accumulation in spinach, and minimise the yield reduction caused by NH4+ toxicity. RESULT The plants were pre-cultured in 8 mmol L-1 NO3- nutrient solution. Next, 6 days before harvest, the plants were transferred to a nutrient solution containing 4 mmol L-1 NO3- and 4 mmol L-1 NH4+. This new mix clearly reduced oxalate accumulation, increased levels of several antioxidant compounds, and enhanced antioxidant capacity in the edible parts of spinach plants, but it did not affect biomass production. However, when the 8 mmol L-1 NO3- was shifted to either nitrogen-free, 4 mmol L-1 NH4+ or 8 mmol L-1 NH4+ treatments, although some of the quality indexes were improved, yields were significantly reduced. CONCLUSIONS Short-term alteration of nitrogen supply prior to harvest significantly affects quality and biomass of spinach plants, and we strongly recommend to simultaneously use NO3- and NH4+ in hydroponic cultivation, which improves vegetable quality without decreasing biomass production. (c) 2013 Society of Chemical Industry