导　　师： 王渭玲

学科专业： 071001

授予学位： 硕士

作　　者： ;

机构地区： 西北农林科技大学

摘　　要： 本论文以根类中药材桔梗Platycodon grandiflorum /(Jacq./) A.DC为研究对象,采用大田试验、盆栽试验以及室内分析相结合的方法,研究了桔梗植株中干物质累积动态,桔梗对氮、磷、钾肥的吸肥规律以及桔梗植株中微量元素含量的动态变化；还对微量元素锌喷施对桔梗生长及有效成分的影响进行了研究。重点研究了氮磷钾肥对桔梗生长及次生代谢产物的影响,并用数学建模的方法建立了桔梗氮磷钾肥对产量和有效成分含量影响的肥效方程,以期为桔梗生产中的精准施肥提供科学依据。主要研究结果如下： 1.桔梗根、茎叶干物质积累量随生育期推进而逐渐增加。出苗后前90天桔梗植株主要是地上部分茎叶生长；出苗后的150-180天内,主要为根部生长。茎叶中氮素含量在出苗后120天达到最高,磷和钾元素最大值出现相对较晚。氮磷钾营养元素在桔梗植株生长衰老期从茎叶向根部转移。桔梗根部和茎叶中营养元素累积量氮素积累量>钾素>磷素。此外,桔梗植株中干物质积累和养分元素累积有明显的线性正相关性。 2.桔梗各部位中Ca、Fe元素含量最大,其中叶中Ca含量最大为15963.73μg//g,根中Fe含量最大值为1869.52μg//g,而Cu含量最小。作为入药部位的桔梗根部含有丰富的Fe,Mn,Cu,Zn矿质元素,且各元素含量在9月份均达到最大值,分别为1869.52μg//g,28.15μg//g,3.56μg//g和24.98μg//g。桔梗叶部中Ca, Mn, Zn元素含量在整个生育期显著高于根部和茎部。 3.不同营养元素对桔梗药材产量和总皂苷含量的影响为氮>钾>磷。各营养元素对桔梗植株多糖含量影响大小为磷>氮>钾,而氮、磷对桔梗总黄酮积累表现出一定负效应。依据桔梗药材产量及总皂苷含量提出桔梗合理施肥方案为N150kg·hm-2、P2O579.41kg·hm-2、K2O225kg·hm-2。氮磷钾合理配施可以促进桔梗植株生长,并对桔梗药材产量和次生代谢产物产生一定影响。氮肥对桔梗营养生长的影响最大,然而氮肥会降低光合产物向根系转移的比例,降低桔梗根冠比,因此桔梗施肥中不能过多施用氮肥。 4.氮磷钾合理配施可以促进桔梗植株光合色素含量以及光合特性。氮磷钾配比为N150kg·hm-2、P2O5225kg-hm-2、K2O79.41kg-hm-2的施肥组合能显著提高桔梗幼苗叶片中叶绿素和类胡萝卜素素含量,降低叶片初始荧光Fo以减少光能无效损耗,并且能增加桔梗幼苗叶片的最大荧光Fm,以及可变荧光Fv,从而使桔梗幼苗叶片的净光合速率显著提高。 5.通过数学建模的方法分别建立了氮磷钾施肥量编码值与第一年生长桔梗和两年生桔梗根产量和总皂苷含量的效应函数。氮、磷、钾肥对桔梗根产量增产作用的大小依次为氮>钾>磷。氮、磷、钾肥对桔梗总皂苷含量的影响大小依次为氮>磷>钾。寻优结果表明：生长第一年桔梗的高产优质/(目标根产量在4200～4800kg//hm2之间,桔梗总皂苷含量高于5.5/%/)优化施肥组合为N113.37～119.41kg//hm2、P2O585.96～134.39kg//hm2、K2O78.80～136.38kg//hm2,N.P205.K20的最优施用量配比为1：0.72-1.18：0.66-1.20；两年生桔梗高产优质/(根产量>7000kg//hm2,总皂苷含量>8/%/)最优施肥组合为N102.44～129.86kg//hm2、P2O581.96～114.36kg//hm2、K2O126.00～172.32kg//hm2,N.P2O5、K2O的最优施用量配比为1：0.63-1.12：1.23-1.68。 6.适宜浓度的喷施锌肥处理能显著提高桔梗幼苗叶片叶绿素a,总叶绿素含量和总胡萝卜素含量,并增强光合特性,减少桔梗根系分根数,并能增加桔梗总皂苷含量。试验确定最佳锌喷施浓度为800mg//L。 This thesis is based on the study of root medicinal plant Platycodon grandiflorum /(Jacq./) A.DC. Both field experiment and pot experiment combined with laboratory analyses were performed. The dynamic accumulation of dry matter in Platycodon grandiflorum plants, the absorption of nitrogen /(N/), phosphorous /(P2O5/) and potassium /(K2O/) by Platycodon grandiflorum plants, and the seasonal change of the contents of trace elements in different organs of Platycodon grandiflorum were investigated. In addition, the effect of Zinc spraying on the growth and effective ingredients of Platycodon grandiflorum was studied based on pot experiment. More importantly, the effect of N, P2O5and K2O on the growth and secondary product metabolism of Platycodon grandiflorum was studied. Furthermore, the effect functions of nitrogen, phosphorus and potassium application codes on the yield and total platycodin of Platycodon grandiflorum were established based on the field experiments using mathematical modeling methods, which is expected to provide scientific basis for accurate fertilizing of Platycodon grandiflorum plants in practical cultivation. 1. The accumulation amount of dry matter in root, stem and leave of Platycodon grandiflorum increased with growth. In the first90days after the emergence of seedlings, above-ground plant parts grew more rapidly. Instead, root of Platycodon grandiflorum intensively developed in the period between the150th day and the180th day after the emergence of seedlings. The nitrogen content in stem and leave reached maximal in the120th day after the emergence of seedlings, and the peak values of the phosphorous and potassium contents appeared relatively later. The accumulation amount of nutritional elements in all organs was in the sequence of nitrogen> potassium> phosphorous. Moreover, the accumulation of dry matter scaled linearly with the accumulation of nutritional elements. 2. The contents of Ca and Fe were the most in all organs of Platycodon grandiflorum. Thereinto, the maximal Ca content reached15963.73μg//g in leave and the maximal content of Fe reached1869.52μg//g in root. Conversely, the content of Cu was the least in all organs. As the main part for medicinal usages, root possessed abundant Fe, Mn, Cu and Zn elements, and the content of all elements reached maximal in September, to be1869.52μg//g,28.15μg//g,3.56μg//g and24.98μg//g respectively. The contents of Ca, Mn and Zn in leave were obviously higher than those in root and stem over the entire growth period. 3. Proper application of N, P2O5and K2O can promote the growth of Platycodon grandiflorum and also enhance the yield and effective ingredients of Platycodon grandiflorum. The effect of N on the growth was the most pronounced. However, too much N application can lower the transfer ratio of photosynthetic products to root. Therefore, it is not good to apply too much N to Platycodon grandiflorum plants. The effect of different nutritional elements on the yield and total saponin of Platycodon grandiflorum was N> K> P. The effect of nitrogen, phosphorus and potassium application on the content of polysaccharide was P> N> K. Nevertheless, both nitrogen and phosphorus had a negative effect on the accumulation of total flavone in Platycodon grandiflorum. 4. Reasonable application of N, P2O5and K2O can improve photosynthetic pigments and also photosynthetic performance in Platycodon grandiflorum plants. The fertilization combination of N150kg-hm·2, P2O5225kg·hm-2and K2O79.41kg-hm-2obviously enhanced the contents of chlorophyll and carotenoid in leaves of Platycodon grandiflorum seedlings, and also significantly lowered the initial fluorescence Fo to reduce invalid optical energy loss. Moreover, it increased the maximal fluorescence Fm, the variable fluorescence Fv and accordingly enhanced the net photosynthetic rate of Platycodon grandiflorum seedlings noticeably. 5. The effect functions of nitrogen, phosphorus and potassium application codes on the yield and total platycodin of both Platycodon grandiflorum growing for one year and biennial Platycodon grandiflorum were established respectively based on the field experiments using mathematical modeling methods. The effect of N, P and K on the yield of Platycodon grandiflorum was N> K> P. The effect of N, P and K on the total saponin of Platycodon grandiflorum was N> P> K. For Platycodon grandiflorum growing for one year, as the target yield was set as4200～4800kg//hm2and the target content of total saponin was set as>5.5/%, the optimal fertilization combination was found to be N113.37～119.41kg//hm2, P2O585.96～134.39kg//hm2, K2O78.80～136.38kg//hm2and the corresponding fertilization ratio of N, P2O5and K2O was1:0.72～1.18:0.66～1.20. For biennial Platycodon grandiflorum, as the target yield was set as more than7000kg//hm2and the target content of total saponin was set as more than8/%, the optimal fertilization combination was found to be N102.44～129.86 kg//hm2, P2O5P2O581.96～114.36kg//hm2, K2O126.00～172.32kg//hm2and the corresponding fertilization ratio of N, P2O5andK2O was1:0.63～1.12:1.23～1.68. 6. Zn spraying with proper Zn concentration can apparently enhance the contents of chlorophyll and carotenoid in leaves of Platycodon grandiflorum seedlings, increase photo synthetic performance, reduce the fractional-root number, and increase the content of total saponin. It was found that the optimal spraying concentration was800mg//L.

关 键 词： 桔梗 氮磷钾 生长发育 有效成分 优化施肥组合

分 类 号： [S567.239]

领　　域： [农业科学] [农业科学]