硼钼铜微肥配施对太子参光合特性的影响

【目的】探究硼钼铜微肥配施对药用植物太子参光合作用的调控作用及其机制,为太子参高效栽培提供理论依据。【方法】采用二次回归D-最优设计进行田间叶面喷施试验,研究硼钼铜微肥配施对光合气体交换参数和叶绿素荧光参数的影响。【结果】①各微肥配施处理下太子参叶片光合色素含量、净光合速率(P_n)、气孔导度(G_s)、蒸腾速率(T_r)较对照均有不同程度的提高,而胞间CO₂浓度(C_i)则显著降低(P<0.05),说明太子参叶片光合能力的提升主要缘于非气孔限制因素的改善。②试验期间,与对照相比,适宜微肥配比处理不同程度地提高了太子参叶片PSⅡ最大光化学效率(F_v/F_m)、PSⅡ有效光化学效率(F_v'/F_m')、电子传递速率(ETR)和光化学淬灭系数(qP),降低非光化学淬灭系数(NPQ),表明微肥处理能够增强太子参光合系统对光能的吸收、转换与利用效率,缓解过剩激发能所导致的热耗散的增强。③极差分析和单因素方差分析表明,微肥3因素中硼是影响叶片光合性能各参数的主要因素,其次为铜。④通过隶属函数综合分析表明,提高太子参光合性能的最优施肥配方为B₃Mo₂Cu₁,即硼肥1.5 g/L+钼肥0.08 g/L+铜肥0.1 g/L。【结论】适宜的硼钼铜配施能有效提升太子参叶片的光合性能,增强其对光能的吸收、转化和利用效率,降低热耗散并缓解光抑制。

Effects of combined application of boron-molybdenum-copper microfertilizers on photosynthetic characteristics of Pseudostellaria heterophylla

【Objective】We studied the regulatory effect of the combined application of B, Mo, and Cu microfertilizers on the photosynthetic characteristics of Pseudostellaria heterophylla to provide a theoretical basis for the efficient cultivation of P. heterophylla. 【Method】A field experiment involving foliar spraying was carried out using a quadratic regression D-optimal design to explore the effects of microfertilizers on photosynthetic gas exchange parameters and fluorescence parameters of P. heterophylla. 【Result】① Compared to the control, the photosynthetic pigment content, net photosynthetic rate (P_n), stomatal conductance (G_s) and transpiration rate (T_r) of the fertilization treatment increased in varying degrees, whereas the intercellular carbon dioxide concentration (C_i) decreased significantly (P<0.05). The results showed that the improvement in photosynthetic capacities of P. heterophylla was mainly due to the relief of non-stomatal limiting factors. ② During the experiment, compared to the control, the PSⅡ maximum photochemical efficiency (F_v/F_m), PSⅡ effective photochemical efficiency (F_v'/F_m'), electron transfer rate (ETR), and photochemical quenching coefficient (qP) of the suitable treatment also increased; whereas, the non-photochemical quenching coefficient (NPQ) decreased. The microfertilizer treatment could enhance the efficiency of the absorption, conversion and utilization of light energy in the photosynthetic system and alleviate the enhanced heat dissipation caused by excess excitation energy. ③ The range analysis and single factor analysis of variance showed that boron played the main role in affecting photosynthetic performance among the three microfertilizers, followed by copper. ④ The comprehensive analysis of membership function showed that the best fertilization formula for improving the photosynthetic performance of P. heterophylla was B₃Mo₂Cu₁ (boron fertilizer 1.5 g/L, molybdenum fertilizer 0.08 g/L and copper fertilizer 0.1 g/L). 【Conclusion】The suitable combined application of boron, molybdenum and copper could effectively improve the photosynthetic performance of P. heterophylla, enhance the efficiency of absorption, transformation and utilization of light energy; while reduce heat dissipation and alleviate photoinhibition.