不同磷浓度对土壤理化性质及防风生长和药材品质的影响

【目的】探讨不同磷浓度处理对土壤特性及防风Saposhnikovia divaricata生长状况、色原酮含量的影响，为防风人工栽培的技术策略制定以及防风对低磷胁迫响应机制的研究提供理论依据。【方法】以2年生防风为材料，设置营养液磷（NH₄H₂PO₄）浓度分别为1.0、0.1和0 （无磷） mmol/L，分别在30、60、90 d时测定土壤理化性质及防风生长特性和4种色原酮总含量，分析不同磷浓度处理防风各指标与4种色原酮总含量的关系。【结果】无磷处理下，2年生防风根粗、根生物量在整个处理期间均低于1.0 mmol·L^-1磷处理，根长在90 d时显著高于1.0和0.1 mmol·L^-1磷处理；土壤pH在60 d后表现为1.0 mmol·L^-1磷处理显著高于0.1 mmol·L^-1和无磷处理；土壤有机质含量在整个试验期表现为1.0和0.1 mmol·L^-1磷处理显著低于无磷处理；90 d时，无磷处理的土壤碱解氮含量显...

Effects of different phosphorus concentrations on soil physicochemical property, growth and medicinal materials quality of Saposhnikovia divaricata

Objective To discuss the effects of different phosphorus concentrations on soil characteristics, growth status and chromone content of Saposhnikovia divaricata, and provide theoretical basis for technical strategy formulation of S. divaricata artificial cultivation and responding mechanism research of S. divaricata to low phosphorus stress. Method Two-year-old S. divaricata was used as material, and three phosphorus treatments with NH₄H₂PO₄ concentration of 1.0, 0.1 and 0 (no phosphorus) mmol/L respectively were set up. The soil physical and chemical properties, and the growth characteristics and total contents of four kinds of chromones in S. divaricata were determined on the 30th, 60th, and 90th day to analyze the correlativity between the various indicators and total chromone content under different phosphorus concentrations. Result The root diameter and weight of 2-year-old S. divaricata in no phosphorus treatment were lower than those of 1.0 mmol·L^?1 phosphorus treatment during the whole treatment period, and the root length after 90 d of treatment was significantly higher than those of 1.0 and 0.1 mmol·L^?1 phosphorus treatments. After 60 d of treatment, the soil pH of 1.0 mmol·L^?1 phosphorus treatment was significantly higher than those of 0.1 mmol·L^?1 and no phosphorus treatments. The contents of soil organic matter in 1.0 and 0.1 mmol·L^?1 phosphorus treatments were significantly lower than that in no phosphorus treatment during the whole treatment period. After 90 d of treatment, the alkali-hydrolyzable nitrogen content in soil of no phosphorus treatment was significantly higher than those of 1.0 and 0.1 mmol·L^?1 phosphorus treatments, whereas the available phosphorus content in soil of 0.1 mmol·L^?1 phosphorus treatment was significantly higher than that of no phosphorus treatment, the total content of four chromones of 0.1 mmol·L^?1 and no phosphorus treatments were significantly higher than that of 1.0 mmol·L^?1 phosphorus treatment. On the 30 th day of treatment, the activities of acid phosphatase in soil among three treatments were significantly different. There were positive correlations between root diameter/root fresh biomass and chromone content in 1.0 mmol·L^?1 phosphorus treatment, between alkali-hydrolyzable nitrogen content/available phosphorus content/root fresh biomass and chromone content in 0.1 mmol·L⁻¹ phosphorus treatment, between pH/alkali-hydrolyzable nitrogen content /acid phosphate activity and chromone content in no phosphorus treatment, respectively. Conclusion S. divaricata has a series of response mechanisms to phosphorus stress, including chromone content significantly increasing, synergistic interaction of pH, organic matter, alkali-hydrolyzable nitrogen and acid phosphatase, which ensures the absorption and utilization of nutrients by S. divaricata.