摘 要

【目的】太子参(Pseudostellaria heterophylla)是中国的传统中药，具有很高的保健和药用价值。本研究采用叶面喷施的方法，通过测定不同质量浓度稀土铈对太子参生理指标、光合日变化和叶绿素荧光动力学参数的影响，初步探讨促进太子参幼苗生理及光合作用的最适质量浓度及其机理，为太子参高产栽培提供理论和应用依据。【方法】通过叶面喷施不同质量浓度稀土铈（CK、25 mg/L、100 mg/L、400 mg/L、700 mg/L），对太子参的生理指标及光合特性进行测定，并进行数据分析。【结果】随着铈质量浓度的增加，太子参植物叶片内的超氧化物歧化酶活性（SOD)、过氧化物酶活性(POD)、可溶性蛋白含量、可溶性糖含量以及叶绿素和类胡萝卜素总量均呈现先增加后下降的趋势，呈明显的浓度效应，以400 mg/L处理效果最佳，丙二醛含量(MDA)则呈现相反的趋势。适当质量浓度稀土铈处理能提高光合日变化参数净光合速率（P_n）、胞间二氧化碳浓度（G_s）、蒸腾速率（T_r）日均值，使胞间二氧化碳浓度（C_i）降低，有效缓解光合“午休”现象。试验期间，PSII最大光化学效率（F_v/F_m）、PSII有效光化学效率（F_v'/F_m'）、PSII实际光化学效率（Φ_PSII)和光化学淬灭系数（qP）随着稀土铈质量浓度的增加均呈现先升高后降低的趋势，以400 mg/L处理效果最佳，非光化学淬灭系数（NPQ）则呈相反的趋势。灰色关联分析表明，色素含量、Φ_PSII和qP是制约太子参光合作用的主要因素。【结论】适当质量浓度的稀土铈处理能提高太子参的各项生理指标，改善光合性能。其对太子参光合作用的调节作用与促进光能吸收、转换、提高光化学效率、缓解光抑制有关。与气孔因素相比，非气孔限制因子的改善是其缓解光合“午休”现象的主要原因。

关键词：太子参；稀土铈；生理特性；光合特性

Abstract

【Objective】Pseudostellaria heterophylla is a traditional Chinese medicine，and its roots have high health and medicinal properties.In this study, the effects of rare earth cerium on the physiological indexes, photosynthetic diurnal changes and chlorophyll fluorescence kinetics parameters of P. Heterophylla were studied by using foliar spraying method. The optimum mass concentration of physiological and photosynthesis And its mechanism, to provide theoretical and application basis for high yield cultivation of P. Heterophylla.【Method】By applying different concentrations of cerium（CK、25 mg/L、100 mg/L、400 mg/L、700 mg/L）on leaf physiological processing Pseudostellaria heterophyll,and then growth indexes and photosynthetic parameters of P. Heterophylla were determined and analysed.【Result】Along with the increase of cerium concentration, superoxide dismutase activity of P.

Heterophylla in plant leaves (SOD), peroxidase (POD) activity, soluble protein content, soluble sugar content and leaf chlorophyll and carotenoid content were increased firstly and then decreased, showed obvious effects of concentration,and content of malondialdehyde (MDA) shows the opposite trend.An optimal cerium concentration of 400 mg/L promoted the above indexes and was found to be statistically significant.Appropriate concentrations of cerium nitrate were found to alleviate photosynthetic depression at midday, as well as improve the mean values of P_n, G_s and T_r associated with the diurnal variation of photosynthetic parameters, while reducing C_i. During the experiment, the chlorophyll fluorescence parameters F_v/F_m, F_v'/F_m, Φ_PSII and qP increased initially and then decreased along with the increasing concentration of cerium, while NPQ followed the opposite trend. Significantly, treatment with 400 mg/L of cerium was found to be optimal. Correlation analysis revealed that P_n had a significantly positive relationship with seeding height and ground diameter, chlorophyll and carotenoid contents, G_s and Φ_PSII, while a negative relationship was observed with C_i and NPQ. Grey correlation analysis (GRA) indicated that the photosynthetic pigments, Φ_PSII and qP were the primary factors impacting photosynthesis.【Conclusion】The appropriate concentration of cerium treatment can improve the physiological indexes of P. Heterophylla, improve photosynthetic performance. The regulating effect on photosynthesis and promote P. Heterophylla light absorption, transformation, improve the efficiency, alleviate the photoinhibition of photochemistry.Regarding stomatal factors, the improvement of the non-stomatal limitation factor was the primary basis for the mitigation of midday photosynthetic depression.

Key words:P. Heterophylla; cerium nitrate; physiology; photosynthetic traits

目录

1 文献综述 1

1.1 太子参的基本介绍 1

1.2 太子参的药理作用 1

1.3 太子参的应用现状及发展趋势 2

1.4 稀土元素简介及在农业上的应用 2

1.5 稀土元素在中药材上的应用现状 3

2 材料与方法 4

2.1 试验地与材料 4

2.2 材料处理方法 4

2.3 测定指标与方法 4

2.3.1 生理指标的测定 4

2.3.2 光合指标的测定 7

2.4 灰色关联分析方法 8

2.4 数据处理方法 8

3结果与分析 10

3.1硝酸铈对太子参生理指标的影响 10

3.1.1 对可溶性糖含量的影响 10