论文标题:氮磷钾营养供应对生菜生长和品质的影响
Effects of N, P, K Nutrient Supply on the Growth and Quality of Lettuce
论文作者
论文导师 别之龙,论文学位 硕士,论文专业 蔬菜学
论文单位 华中农业大学,点击次数 1331,论文页数 87页File Size6909K
2006-05-01论文网 http://www.lw23.com/lunwen_119452/
nitrogen; phosphorus; potassium; growth; quality
本试验以两个散叶生菜品种(“弘农”和“绿领”)为材料，采用水培方式研究了氮磷钾营养供应对生菜生长和品质的影响。试验由不同氮素供应、不同磷素供应、不同钾素供应和氮磷钾通用正交旋转组合设计对生菜生长和品质的影响四部分组成。 1．利用四种不同氮浓度(2、4、6、8mmol／L)处理研究了其对生长和品质的影响。结果表明，供氮水平由2mmol／L增加到4mmol／L，生菜的地上干鲜重、根干鲜重、叶面积和根冠比显著增加，再增加氮浓度则显著下降。随着氮浓度的增加，生菜叶片的硝酸盐含量和硝酸还原酶活性显著升高。生菜地上部干物质积累随定植后时间的延长而增加，采收前4mmol／L氮素处理下地上部干物质积累最大。供氮水平由2mmol／L增加到6mmol／L，净光合速率(Pn)、气孔导度(Gs)和蒸腾速率(E)显著增加，继续提高氮水平则Pn、Gs和E有降低的趋势；而胞间CO_2浓度(Ci)随着供氮水平的提高显著下降。2～8mmol／L氮素水平范围内，生菜叶片的最大光化学效率(Fv／Fm)、PSⅡ的激发能捕获效率(Fv"／Fm")、光系统Ⅱ(PSⅡ)的电子传递效率(ΦPSⅡ)、电子传递速率(ETR)和光化学猝灭系数(qP)随着供氮水平的增加而增加，而非光化学猝灭系数(NPQ)显著下降。可溶性蛋白和维生素C含量随着氮素处理浓度的升高而增加。4mmol／L氮素处理显著增加了生菜体内全氮全磷含量；随着氮处理浓度的增加，生菜叶片的全钾含量逐渐降低，而全镁含量有升高的趋势。4mmol·／L氮素处理是4个氮处理中最适合生菜水培的氮浓度。 2．采用四种不同磷浓度(0.1、0.5、0.8、1.0mmol／L)处理研究了其对生长和品质的影响。结果表明，随着磷素供应浓度的增加，生菜地上部干鲜重、根干鲜重和叶面积显著增加，并在0.5mmol／L下达最大值，继续增加磷素水平则显著下降。定植15d后，0.5mmol／L处理下的干物质积累显著高于其它处理。随着磷素供应水平的增加，生菜叶片中的酸性磷酸酯酶活性显著降低，各处理之间差异显著。净光合速率、气孔导度和蒸腾速率在0.5mmol·／L处理下有最大值，而胞间CO_2浓度随磷浓度的增加而迅速降低。随着磷处理浓度的增加，PSⅡ的激发能捕获效率和光系统Ⅱ(PSⅡ)的电子传递效率逐渐降低，而非光化学猝灭系数逐渐上升。生菜的可溶性蛋白和维生素C在0.5mmol／L处理下有最大值，并在0.5mmol／L处理下有高的可溶性糖含量和较小的硝酸盐含量。0.5mmol／L磷素处理下，生菜的体内有较高的氮、磷、钾和镁含量。0.5mmol／L磷素处理是4个磷处理中最适合生菜水培的磷浓度。 3．研究了四种不同钾浓度(1、4、6、8mmol／L)处理对生菜生长和品质的影响。结果表明，生菜地上部和根部的鲜重、干重和叶面积随着钾处理浓度的增加而增加，并在4.0mmol／L处理下达最大值，继续增加钾水平则显著下降。随着定植后天数的增加，4.0mmol／L钾处理下的地上干物质累积显著高于其它处理。6.0 mmol／L处理下的硝酸还原酶活性最高。生菜的净光合速率、气孔导度和蒸腾速率在1～6mmol／L钾素水平处理范围内随供钾水平的增加而增加，而超过6mmol／L却随着供钾水平的增加而降低。1～4mmol／L钾素水平处理范围内，胞间CO_2浓度随钾浓度的增加而迅速降低，而当供钾水平超过4mmol／L，随着钾浓度的增加，胞间CO_2浓度无显著变化。随着钾处理浓度的增加，最大光化学效率、PSⅡ的激发能捕获效率、光系统Ⅱ(PSⅡ)的电子传递效率和电子传递速率逐渐升高，并在6 mmol／L钾素处理下有最大值，继续增加钾素浓度则有降低的趋势；而光化学猝灭系数和非光化学猝灭系数随着钾处理浓度的增加而降低，在6mmol／L下有最小值，继续增加钾素供应则显著升高。随着钾处理浓度的增加，硝酸盐含量显著降低；4.0 mmol／L处理下有最大的可溶性糖含量，以及高的可溶性蛋白和维生素C含量。4.0 mmol／L钾素供养增加了生菜地上部和根部的全氮、全磷、全钾含量。生菜叶片中的全钙含量在4.0mmol／L处理下最大，而叶片中的全镁含量在1.0 mmol／L处理下最大。4.0mmol／L钾素处理是4个钾处理中最适合生菜水培的钾浓度。 4．采用通用旋转组合设计，利用水培法研究了氮磷钾施用量对生菜(品种为“绿领”)产量和品质的影响，获得了相应的数学模型。结果表明，氮磷钾三者对产量影响的大小顺序为：N＞P＞K，互作效应对产量影响的大小顺序为：NP＞NK＞PK；对生菜叶片中硝酸盐含量影响的大小顺序为：N＞K＞P，互作效应对硝酸盐含量影响的大小顺序为：NP＞NK＞PK；对可溶性蛋白含量影响的大小顺序为：N＞K＞P，互作效应对可溶性蛋白含量影响的大小顺序为：NK＞NP＞PK；对可溶性糖含量影响的大小顺序为：N＞K＞P，互作效应对可溶性糖含量影响的大小顺序为：NP＞PK＞NK：对维生素C含量影响的大小顺序为：N＞P＞K，互作效应对Vc含量影响的大小顺序为：NP＞PK＞NK。当氮、磷、钾各因子的浓度分别为：3.07mmol／L、0.582mmol／L、2.666 mmol／L时生菜可以达到高产优质生产目标。
Effects of different concentration of nitrogen, phosphrus and potassium on the growth and quality of lettuce(cv. "Hongnong" and "Lvling") were investigated by using hydroponics. The study consisted of four experiments: different nitrogen supply, different phorophrus supply, different potassium supply and the combination of nitrogen, phorophrus and potassium supply experiment. The main results were as follows:1. Effects of different nitrogen supply(2, 4, 6, 8mmol/L) on the growth and quality of the lettuce were investigated. The results showed that the fresh and dry weights of shoot and root,leaf area and root/shoot ratio were significantly increased as N level increasing from 2 to 4 mmol/L , and then decreased as N level further increased.The nitrate content and nitrate reductase activity increased significantly with increasing of the nitrogen concentration. Shoot dry weight increased steadily along with the days after transplanting.The largest dry matter accumulation of shoot was obtained by 4 mmol/L N. Net photosynthesis rate (Pn),stomatal conductance (Gs) and transpiration rate(E) were significantly increased as N level increasing from 2 to 6 mmol/L and then decreased as N level further increased, whereas intercelluar CO_2 concentration (Ci) decreased obviously as N level increased . Maximal photochemical efficiency of PS II (Fv/Fm), the PS II excitated capture efficiency (Fv"/Fm"), the light system II (PS II) the electron transfer efficiency (OPS II), the electron transfer rate (ETR) and the photochemical quenching (qP) were drastically increased by increasing N level from 2 to 8 mmol/L, whereas non-photochemical quenching (NPQ) decreased obviously as N level increased. The soluble protein and the vitamin C contents increased obviously by increasing N level. The highest total nitrogen and phosphorus content were obtained by 4 mmol/L nitrogen treatment. Potassium content increased whereas magnesium decreased as nitrogen concentration in the nutrient solution increased. The optimal nitrogen concentration for lettuce hydroponics was 4 mmol/L in four N treatments.2. Effects of different phosphorus supply(0.1, 0.5, 0.8, 1.0 mmol/L) on the growth and quality of the lettuce were investigated. Results showed that the lettuce"s the fresh and dry weights of shoot and root and leaf area were drastically increased as increasing P level, which had the maximum value under 0.5 mmol/L P then decreased as P level further increased. After the days after transplanting 15d, the largest dry matter accumulation of shoot was obtained by 0.5mmol/L P. The Apase activity remarkably reduced with increasing of the phosphorus concentration. Net photosynthesis rate , stomatal conductance and the transpiration rate have the maximum value under 0.5 mmol/L, whereas intercelluar CO_2 concentration decreased obviously as N level increased. Along with P level increased, the PSⅡexcitated capture efficiency, the light systemⅡ(PSⅡ) the electron transfer efficiency decreased obviously, whereas non- photochemical quenching increased obviously. The soluble protein and vitamin C have the maximum value under 0.5 mmol/L. At 0.5mmol/L, soluble sugar content relatively high, nitrate content was relatively low. Moreover, at 0.5 mmol/L P treatment, nitrogen content, phosphorus content, potassium and magnesium content relatively high. Therefore, the optimal phosphorus concentration for lettuce hydroponics was 0.5 mmol/L in four P treatments. 3. Effects of different potassium supply(1, 4, 6, 8mmol/L) on the growth and quality of the lettuce were investigated. Results showed that the fresh and dry weights of shoot and root and leaf area were significantly increased by increasing K level, which had the maximum value under 4.0 mmol/L K level then decreased as K level further increased. With the days after transplanting increasing, at 4.0 mmol/L K, the largest dry matter accumulation of shoot was obtained by 4 mmol/L K. The largest nitrate reductase activity was obtained by 6.0 mmol/L K. Net photosynthesis rate, stomatal conductance and the transpiration rate were significantly increased as K level increasing from 1 to 6 mmol/L and then decreased as K level further increased. Intercelluar CO_2 concentration was significantly reduced as K level increasing from 1 to 4 mmol/L and then not remarkably changed as K level further increased. Photochemical efficiency of PSⅡ, the PSⅡexcitated capture efficiency, the light systemⅡ(PSⅡ) the electron transfer efficiency and the electron transfer rate were drastically increased as K level increasing, which had the maximum value under 6.0 mmol/L K then decreased as K level further increased.The photochemical quenching and non-photochemical quenching were drastically decreased as K level increasing, which had the minimum value under 6.0 mmol/L K level and then increased as K level further increased. Along with K concentration increased, the nitrate content remarkably reduced. At 4.0 mmol/L K, soluble sugar content, soluble protein and vitamin C content relatively high. 4.0 mmol/L potassium element processing increased entire nitrogen, phosphorus and potassium content of lettuce. At 4.0 mmol/L K, entire calcium content is biggest, but leaf"s entire magnesium content is biggest under 1.0 mmol/L. The optimal potassium concentration for lettuce hydroponics was 4.0 mmol/L in four K treatments. 4. Using the general quadratic rotatory regression and solution cultivation, the effects of N, P, K on the growth and quality of the lettuce were investigated, and mathematical model were established. Results showed that the nitrogen phosphorus potassium to the output influence size order is: N＞P＞K, the interactive effects on output of N,P,K was in the order as: NP＞NK＞PK. To the nitrate content was in the order as: N＞K＞P, interactive effects on nitrate content of N,P,K was in the order as: NP＞NK＞PK. To the soluble protein content was in the order as: N＞K＞P, interactive effects on soluble protein of N,P,K was in the order as: NK＞NP＞PK. To the soluble sugar content was in the order as: N＞K＞P, interactive effects on soluble sugar of N,P,K was in the order as: NP＞PK＞NK. To the vitamin C content was in the order as: N＞P＞K, interactive effects on vitamin C of N,P,K was in the order as: NP＞PK＞NK. When the nitrogen, the phosphorus, the potassium various factors concentration respectively is: 3.07mmol/L,0.582 mmol/L,2.666 mmol/L the lettuce may achieve the high yield and quality goal.
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