氮素形态对小白菜根系和硝酸盐含量的影响  

Effects of Nitrogen Form on Root Morphology and Nitrate Concentrations of Pakchoi

作　　者：韩瑞锋[1] 梁韵[1] 黄丹枫[1] HAN Rui-feng LIANG Yun HUANG Dan-feng(School of Agriculture and Biology,Shanghai Jiaotong University, Shanghai 200240,Chin)

机构地区：[1]上海交通大学农业与生物学院,上海200240

出　　处：《上海交通大学学报（农业科学版）》2017年第3期37-44,共8页Journal of Shanghai Jiaotong University(Agricultural Science)

基　　金：国家自然科学基金委员会重点项目(61233006);国家"863"项目(2013AA1030006-03)

摘　　要：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,本试验采用无菌溶液培养技术,在以硝态氮(NO_3^--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NO_3^--N浓度为2和10mmol/L时,添加0.5、2.5、12.5mmol/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、2.5mmol/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NO_3^--N浓度为10mmol/L时与2mmol/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GlyN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。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%0 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 GlyN, 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. 40% 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.

关 键 词：甘氨酸 硝酸盐 根系形态 小白菜 

分 类 号：S143.1[农业科学—肥料学] S634.3[农业科学—农业基础科学]