氮磷肥配施对西北羊茅开花期叶片光合特性日变化的影响  

Effects of nitrogen and phosphorus fertilizers combined application on diurnal variations of leaves photosynthetic characteristics in Festuca kryloviana

作　　者：石正海 刘文辉[1] 张永超[1] 秦燕[1] 魏小星[1] SHI Zheng-hai;LIU Wen-hui;ZHANG Yong-chao;QIN Yan;WEI Xiao-xing(Key Laboratory of Superior Forage Germplasm in the Qinghai-Tibetan Plateau,Qinghai Academy of Animal Science And Veterinary Medicine,Qinghai Universtiy,Xining 810016,China)

机构地区：[1]青海省青藏高原优良牧草种质资源利用重点实验室青海省畜牧兽医科学院青海大学

出　　处：《草业学报》2019年第11期75-85,共11页Acta Prataculturae Sinica

基　　金：青海省科技厅重点实验室发展专项“青海省青藏高原优良牧草种质资源利用重点实验室”(2017-ZJ-Y09),“现代农业产业技术体系建设专项资金”(CARS-34);农业部“牧草种质资源保护项目”(2130135)资助

摘　　要：基于植物对N、P营养元素的需求,试验设计2个施氮量(0、60 kg·hm^-2)和3个施磷量(0、60、90 kg·hm^-2)配施,测定开花期叶片在不同光合有效辐射下的气体交换参数和叶绿素荧光参数,探讨西北羊茅对氮、磷添加和光合有效辐射的响应。结果表明,光合有效辐射呈先增后减的日动态变化,下午13:00时高达2000μmol·m^-2·s^-1,且对西北羊茅光合特性的影响大于施肥措施。净光合速率随光合有效辐射增强先增后降,其值在800~1000μmol·m^-2·s^-1时最大;气孔导度、气孔限制值、蒸腾速率和水分利用效率与净光合速率表现一致,胞间CO2浓度表现相反。氮肥和磷肥配施后气孔导度、气孔限制值和蒸腾速率均增大,胞间CO2浓度则减小,表明施肥主要通过调节气孔导度,以促进叶片与环境间交换水分和CO2,从而增大净光合速率。随光合有效辐射增强,PSⅡ有效光化学效率、PSⅡ实际光化学效率和光化学猝灭系数显著降低,非光化学猝灭系数显著增加,电子传递速率先增加后降低,但均在400~800μmol·m^-2·s^-1和大于1200μmol·m^-2·s^-1后快速变化。氮肥和磷肥配施显著提高PSⅡ有效光化学效率、PSⅡ实际光化学效率、光化学猝灭系数和电子传递速率,N60P90处理还提高PSⅡ最大光化学效率和非光化学猝灭系数。在光能分配方面,为减轻强光对光合器官的破坏,随光合有效辐射增强光化学反应比例降低,天线热耗散和非光化学反应耗散比例增加。施肥主要通过非光化学反应比例减小补偿于光化学反应比例,从而提高光能利用率。综合以上结果,从西北羊茅叶片的光合特性来看,氮磷肥配施通过调节气孔导度,以促进叶片与环境间水分和CO2的交换和提高PSⅡ反应中心活性,非光化学反应比例减小补偿于光化学反应比例,进而增加叶片净光合速率。Nitrogen and phosphorous are the two basic elements needed for plant growth, we carried out this experiment with two different levels of nitrogen(0, 60 kg·ha^-1) and three difference levels of phosphorous(0, 60, 90 kg·ha^-1) addition treatments, to investigate the effect of fertilizer addition and daily light radiation on the photosynthetic characters on Festuca kryloviana by analysis the leaf gas exchanges parameters and chlorophyll fluorescence parameters. As the results shown, the photosynthetically active radiation increased and decreased in the daytime, the peak value was at 13:00 p.m. 2000 μmol·m^-2·s^-1, and which the effect on the photo index were more significant than the fertilizer addition. Net photosynthetic rate(Pn) increased first then decreased with the increasing photosynthetically active radiation and its value was the highest at 800-1000 μmol·m^-2·s^-1. The change of stomatal conductance(Gs), stomatal limited value(Ls), transpiration rate(Tr), water use efficiency(WUE) were consistent with Pn, but the intercellular CO2 concentration(Ci) was opposite. After the nitrogen and phosphorus addition, Gs, Ls and Tr increased, and Ci decreased, indicated that the increase of Pn after fertilization were mainly by the increasing of the water and CO2 exchange among the leaves and the environment. With the increasing of photosynthetically active radiation, the effective photochemical efficiency of PSⅡ(Fv′/Fm′), the actual photochemical efficiency of PSⅡ(ΦPSⅡ) and the photochemical quenching coefficient(qP) were significantly reduced, the non-photochemical quenching coefficient(NPQ) increased significantly and the electron transport rate(ETR) increased first and then decreased, the scale was among the 400 to 800 μmol·m^-2·s^-1 and changed rapidly after 1200 μmol·m^-2·s^-1. Nitrogen and phosphorus fertilizers significantly increased Fv′/Fm′, ΦPSⅡ, qP and ETR. In particular, N60P90 treatment also increased the maximum photochemical efficiency of PSⅡ(Fv/Fm) and NPQ. In terms of

关 键 词：西北羊茅 氮磷配施 开花期 气体交换参数 叶绿素荧光参数 光能分配 

分 类 号：S51[农业科学—作物学]