远志养分吸收规律及其与药效成分积累的关系

【目的】 远志 (Polygala tenuifolia Willd) 是多年生草本植物，以根入药，是我国重要的大宗药材之一。研究远志的营养元素吸收规律及其与药效成分积累的关系，为远志人工栽培中科学施肥及专用肥料的研制提供理论依据。 【方法】 以3年生远志为研究对象，2017年3月26日幼苗全部返青，从返青后40天 (5月4日) 开始，每隔20 天田间采集植株样一次，分别测定其根部和地上部干物质量，氮磷钾等8个营养元素含量以及根中3类药效成分 (总皂苷、总黄酮和总酚) 的含量。 【结果】 远志地上部干物质积累在整个生育期内呈先升高后下降的趋势，根部干物质积累呈直线上升趋势。返青后40～140 天地上部干物质积累量大于根，返青后 160～195天生长中心转移到根，根的干物质积累量大于地上部。远志植株对氮素的最大吸收时期在返青后100～140天，吸收量为18.77 g/m2，对磷、钾的最大吸收时期在返青后140 天，吸收量分别为3.07 g/m2和3.36 g/m2。远志根中总皂苷、总黄酮、总酚累积量的趋势基本一致，均为先升高后降低，累积量均在返青后180天达到最大值。总皂苷积累量出现两次峰值，分别在返青后140天 (6.28 g/m2) 和180天 (6.43 g/m2)，总酚累积量也出现两次峰值，分别在返青后80天 (2.37 g/m2) 和180天 (4.31 g/m2)，总黄酮积累量只有一次峰值，出现在返青后180天 (2.35 g/m2)。根药效成分经济产量在返青后180天达到最高。总黄酮含量与根中锌元素含量呈显著正相关 (P < 0.05)；总酚含量与根中锌元素含量呈极显著正相关 ( P < 0.01)。 【结论】 返青后140～195天是远志根干物质积累最快的时期。远志氮营养最大效率期在返青后100～140天，磷、钾营养最大效率期在返青后140天。在远志专用肥料配制中应保证锌元素的供给，以满足远志生长发育的需求，从而有效提高药效成分的积累。远志根秋季采挖的最佳时间是返青后180天 (9月25日)。

Nutrient uptake rules of Polygala tenuifolia and its relationship with accumulation of bioactive components

【Objectives】 Polygala tenuifolia, a Chinese medicine herb whose root is the harvested part, is one of the main commoditized raw materials. The rules of nutrient absorption and its relationship with the accumulation of bioactive components were studied, in order to provide theory for scientific fertilizer application in Polygala tenuifolia. 【Methods】 The 3-year-old P. tenuifolia plants were taken as the research material. Since turning green on March 26 of 2017, plant samples were collected at the 40, 60, 80, 100, 120, 140, 160, 180 and 195 days after revival. The dry matter accumulations, the contents of nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), iron (Fe), copper (Cu), zinc (Zn) in roots and the aboveground parts were analyzed. At the same time, the contents of saponins, flavonoids and phenols in roots of different growth periods of P. tenuifolia were measured. 【Results】 The dry matter accumulation in the aboveground parts of P. tenuifolia increased first and then decreased, and that in roots kept a linear increasing during the whole growing period. The dry matter accumulation of the aboveground parts was greater than that of roots from 40 days to 140 days after turning green. With the growth center transferred to roots from the 160 days to 195 days after revival, the dry matter accumulation of roots was greater than that of the aboveground parts. The maximum N absorption capacity of P. tenuifolia was from 100 days to 140 days after revival with the absorption amount of 18.77 g/m2, and the maximum P and K absorption capacity was 140 days after revival, with the absorption amounts of 3.07 g/m2 and 3.36 g/m2, respectively. The accumulation of saponins and flavonoids in the whole growth period in roots of P. tenuifolia all showed two peaks, for saponins they appeared at 140 days (6.28 g/m2) and 180 days (6.43 g/m2) and for phenols at 80 days (2.37 g/m2) and 180 days (4.31 g/m2) after revival. The accumulation of flavonoids appeared one peak at 180 days revival green (2.35 g/m2). The economic yield of root bioactive components reached the highest at the 180 days after revival. A positive and significant correlation was found between flavonoid content and Zn content in root (P < 0.05), and it was extremely significant between phenol content and Zn content in root ( P < 0.01). 【Conclusions】 The rapid dry matter accumulation in roots is from 140 days to 195 days after the revival of P. tenuifolia plants, which is more than 40 days behind the peak accumulation of N P and K by the plants. Zinc content plays very important role in the contents of the bioactive components. For the highest economic profits, balanced fertilization of NPK with Zn should be paid more attention, and the proper harvest time of P. tenuifolia is also very important, which is at about 180 days after the revival (25 th, September) under the experimental condition.