%0 Journal Article %T 氮素形态对小白菜根系和硝酸盐含量的影响</br>Effects of Nitrogen Form on Root Morphology and Nitrate Concentrations of Pakchoi %A 韩瑞锋 %A 梁韵 %A 黄丹枫 %J 上海交通大学学报农业科学版 %D 2017 %X 为改善蔬菜品质,减少生产中叶菜类硝酸盐累积严重的问题,本试验采用菌溶液培养技术,在以硝态氮(NO3--N)为氮源的基础上,添加不同浓度甘氨酸态氮(Gly-N),对小白菜根系形态、生物量、叶片硝酸盐含量及相关品质变化进行研究。结果发现,小白菜鲜重、根冠比和叶片硝酸盐含量随着添加Gly-N浓度增加而降低(P＜0.001),同时根系生长也受到明显抑制(P＜0.05);相反,干物质、叶绿素含量(SPAD)、叶片游离态氨、游离氨基酸、可溶性蛋白质和可溶性糖含量却增加(P＜0.05)。当NO3--N浓度为2和10 mmol/L时,添加0.5、2.5、12.5 mmol/L Gly-N处理主根长与单一硝态氮相比分别减少38.2%(P＜0.05)、47.7%(P＜0.05)、68.2%(P＜0.05)和33.4%(P＜0.05)、43.6%(P＜0.05)、51.2%(P＜0.05);添加0.5、2.5 mmol/L Gly-N处理叶片硝酸盐含量与单一硝态氮相比分别降低56.0%(P＜0.05)、75.1%(P＜0.05)和20.9%(P＜0.05)、51.4%(P＜0.05);并且硝酸盐含量与根表面积、根体积呈显著正相关(P＜0.05)。当NO3--N浓度为10 mmol/L时与2 mmol/L处理相比,小白菜根直径、SPAD和叶片可溶性糖含量减少(P＜0.05);而叶片硝酸盐和可溶性蛋白质含量却增加(P＜0.05)。这些结果表明,添加Gly-N可以明显降低以硝态氮为氮源下小白菜叶片中硝酸盐的累积,并且抑制根系生长,对小白菜品质的改善起到了很好的作用。</br>In order to reduce the nitrate accumulation in leafy vegetables and improve the quality,a sterile hydroponic experiment was conducted to study the effects of different concentrations of exogenous Glycine (Gly)-N on the root morphology,biomass,nitrate contents and other quality in the leaves of pakchoi under the nitrate-N (NO3--N) supply.The results showed that the fresh weight,Root/Shoot Ratio and nitrate content in leaves of pakchoi significantly decreased (P＜0.001) and the root growth was inhibited (P＜0.05); however,the dry matter,chlorophyll content (SPAD),free ammonia,free amino acid,soluble protein and soluble sugar contents in leaves significantly increased (P＜0.05) with increasing of exogenous Gly-N concentrations.Compared to the single NO3--N treatment,the primary root length decreased by 38.2% (P＜0.05),47.7% (P＜0.05),68.2% (P＜0.05) under 2 mmol/L NO3--N and 33.4% (P＜0.05),43.6% (P＜0.05),51.2% (P＜0.05) under 10 mmol/L NO3--N in the treatments of 0.5,2.5,12.5 mmol/L exogenous Gly-N,respectively; the nitrate contents in leaves decreased by 56.0% (P＜0.05),75.1% (P＜0.05) under 2 mmol/L NO3--N and 20.9% (P＜0.05),51.4% under 10 mmol/L NO3--N in the treatments of 0.5,2.5 mmol/L exogenous Gly-N,respectively.In addition,the nitrate contents in leaves were significantly correlated with root surface area and root volume (P＜0.05).Compared to 2 mmol/L NO3--N treatment,root diameter,SPAD and soluble sugar content in leaves were significantly lower (P＜0.05),whereas nitrate and soluble protein content in leaves were significantly higher (P＜0.05) under 10 mmol/L NO3--N treatment.It was suggested that exogenous Gly-N could reduce the nitrate accumulation in leaves of pakchoi under NO3--N supply and inhibit the root growth.It will be helpful to improve the quality of pakchoi. %K 甘氨酸 硝酸盐 根系形态 小白菜< %K /br> %K Glycine nitrate root morphology pakchoi %U http://shjtdxnxb.cnjournals.com/ch/reader/view_abstract.aspx?file_no=20170306&flag=1