摘要
【目的】探索不同磷素水平下米槁(C_innamomum migao H.W.Li)幼苗光合作用对CO_2的响应机制,为西南地区推广种植米槁及其科学施用磷肥提供参考依据。【方法】以0.5年生米槁幼苗为对象,设4个磷素(KH_2PO_4)供给浓度(CK为1.000 mmol/L,P_1、P_2和P_3处理分别为0.125、0.500和2.000 mmol/L)处理,测定各处理米槁幼苗的光合特性,利用直角双曲线模型、非直角双曲线模型及直角双曲线修正(P_n/C_i)模型拟合米槁幼苗的光响应曲线和参数。【结果】3种米槁幼苗光响应曲线拟合模型的拟合决定系数R^2均在0.9900以上,表达的效力趋势排序为P_n/C_i模型>非直角双曲线模型>直角双曲线模型,以P_n/C_i模型对米槁的光合作用—CO_2响应最实用,且不同磷素水平下模型拟合效力均符合此效力趋势。各磷素供给处理中,除胞间CO_2浓度(C_i)外,净光合速率(P_n)、气孔导度(G_s)和蒸腾速率(T_r)的排序均为CK>P_3>P_2>P_1,且P_1处理的P_n、G_s和T_r均与其他处理差异显著(P<0.05),表明1.000 mmol/L KH_2PO_4处理下米槁幼苗的光合作用效率最高。【结论】P_n/C_i模型最适宜进行米槁幼苗光合作用—CO_2响应拟合;施用适量磷素能促进米槁幼苗的光合作用,最适宜米槁幼苗生长的土壤磷含量为1.000 mmol/L。
【Objective】This study was conducted to explore the response mechanism of photosynthesis to CO2in Cinnamomum migao H.W.Li seedlings under different phosphorus levels,in order to provide reference for scientific phosphorus application and cultivation of C.migao in southwestern China.【Method】This study took half-year C.migao seedlings as experimental material.Four phosphorus(KH2PO4)supply concentrations(CK was1.000mmol/L,P1,P2and P3were0.125,0.500and2.000mmol/L respectively)were set.Photosynthetic characteristics of the C.migao seedlings under different treatments were determinated,and light response curves and parameters were fitted by using right angle hyperbola model,non-right angle hyperbola model and modified right angle hyperbola model(Pn/Ci).【Result】Determination coefficients R2of the three fitting models on C.migao seedlings photosynthesis response were above0.9900,and the effectiveness trend was Pn/Ci model>non-right angle hyperbola model>right angle hyperbola model.Pn/Ci model was the most practical one for photosynthesis-CO2response of C.migao seedlings,and fitting effectiveness of the model was in line with this trend under different phosphorus levels.Under all phosphorus treatments,except intercellular CO2concentration(Ci),the rank of net photosynthetic rate(Pn),stomatal conductance(Gs),and transpiration rate(Tr)was CK>P3>P2>P1,and Pn,Gs and Tr under P1treatment were significantly different from those under other treatments(P<0.05),which showed that the photosynthetic efficiency of C.migao seedlings was the highest under1.000mmol/L KH2PO4treatment.【Conclusion】The Pn/Ci model is the most suitable for photosynthesis-CO2response fitting of C.migao seedlings.Appropriate application of phosphorus can promote C.migao photosynthesis.The most suitable content of phosphorus in soil for C.migao seedlings is1.000mmol/L.
作者
熊雪
刘济明
王军才
柳嘉佳
李佳
邓明明
XIONG Xue;LIU Ji-ming;WANG Jun-cai;LIU Jia-jia;LI Jia;DENG Ming-ming(College of Forestry,Guizhou University,Guiyang 550025,China;Shanghai Jiao Tong University,Shanghai 200240,China)
出处
《南方农业学报》
CAS
CSCD
北大核心
2017年第11期1983-1988,共6页
Journal of Southern Agriculture
基金
贵州省科技计划项目(黔科合SY字[2015]3023-1)
贵州省林业厅重大项目(黔林科合[2010]重大04号)
贵州大学研究生创新基金项目(研农2017012)
关键词
米槁幼苗
光合作用
CO2响应
双曲线模型
土壤磷含量
Cinnamomum migao H. W. Li seedlings
photosynthesis
CO2 response
hyperbolic model
soil phosphorus content
