黄栌叶片光合特性对氮磷钾配施的响应

Response of leaf photosynthetic characteristics of Cotinus coggygria to combined application of mineral nitrogen,phosphorus and potassium

【目的】通过研究黄栌叶片光合特性对氮磷钾配施处理的响应,探讨光合特性与氮磷钾肥的关系,为黄栌的养分管理提供科学依据。【方法】以黄栌盆栽苗为试验材料,根据L9(34)正交设计进行氮肥(N为0、6、12 g/株)、磷肥(P为0、10、20 g/株)和钾肥(K为4、8、12 g/株)试验,设置10个处理,分别为T1(N1P1K1)、T2(N1P2K2)、T3(N1P3K3)、T4(N2P1K2)、T5(N2P2K3)、T6(N2P3K1)、T7(N3P1K3)、T8(N3P2K1)、T9(N3P2K1)和T10(N0P0K0)。测定不同配施下黄栌叶片的光合色素含量、叶面积、光合参数日变化和光响应曲线,分析氮磷钾与黄栌叶片光合特征参数的关系。【结果】各处理黄栌叶片净光合速率(Pn)和气孔导度(Gs)呈双峰型曲线变化,蒸腾速率(Tr)呈单峰型曲线变化。T5、T6和T8的叶绿素总量(Chl s)和类胡萝卜素(Car)含量较高;除T2外,其余处理的Pn日平均值显著高于对照(P<0.05),其中T5、T6和T9较高。T9的光合日变化参数值(Pn、Tr、Gs和光能利用效率(LUE))以及光响应参数值(最大净光合速率(Pnmax)、光饱和点(LSP)、光补偿点(LCP)和暗呼吸速率(Rd))日平均值最高。冗余分析结果表明,肥料贡献率大小为磷肥>氮肥>钾肥。其中磷对光合色素(Chl s和Car)的影响大,与Pn、Pnmax和LSP正相关程度较显著。氮钾对LUE的影响大,同时LUE与LCP、Tr和Gs正相关程度较显著。【结论】本研究T9(氮肥施用量12 g/株、磷肥施用量20 g/株、钾肥施用量8 g/株)是本试验的最优处理,进一步说明磷肥对提高黄栌叶片光合色素含量起重要作用,从而显著促进黄栌叶片的光合能力。

[Objective]Relationship between photosynthetic characteristics and combined application of mineral nitrogen,phosphorus and potassium(N,P and K)has been studied to provide nutrient management strategies of Cotinus coggygria.[Method]Under 10 treatments(see below),the photosynthetic pigment,leaf area,diurnal variation of photosynthetic parameters and light response curve of leaves of potted C.coggygria seedlings were measured,and theses generated data were then related to combined application of N,P and K.With a L9(34)orthogonal design for N(0,6,12 g/plant),P(0,10,20 g/plant)and K(4,8,12 g/plant),these 10 treatments were T1(N1P1K1),T2(N1P2K2),T3(N1P3K3),T4(N2P1K2),T5(N2P2K3),T6(N2P3K1),T7(N3P1K3),T8(N3P2K1),T9(N3P2K1)and T10(N0P0K0).[Result]Under each treatment,the net photosynthetic rate(Pn)and stomatal conductance(Gs)had a“double peak curve”change,while the transpiration rate(Tr)had a“single peak curve”change.The contents of total chlorophyll and carotenoid were higher under T5,T6 and T8 than under other treatments.Except for T2,the daily average value of Pn was significantly higher than control(P<0.05).Among all the 10 treatments,T9 had the highest performance on all the tested diurnal variation parameters(Gs,Pn,Tr and light energy use efficiency(LUE)),and the daily average values of light response parameters(maximum net photosynthetic rate(Pnmax),light saturation point(LSP),light compensation point(LCP)and dark absorption rate(Rd)).In addition,the redundancy analysis showed that the contribution rate of fertilizer was P>N>K,while P had a greater effect on photosynthetic pigments(Chl s and Car)and a positive correlation with Pn,Pnmax and LSP.In contrast,N and K had greater influences on LUE,which was positively correlated with LCP,Tr and Gs.[Conclusion]Results from this experiment demonstrate that among the tested 10 NPK treatments,T9(12 g/plant N,20 g/plant P and 8 g/plant K)is the optimal fertilization to significantly promote leaf photosynthetic capacity of C.coggygria.