保水剂与氮肥对鼓节竹光合特性和叶绿素荧光特性的影响

本研究以3年生鼓节竹为研究材料,研究单施氮肥（150、300、450 g/丛）以及保水剂（180 g/丛）与氮肥（150、300、450 g/丛）混施对鼓节竹叶绿素、叶片光合参数和叶绿素荧光参数的影响,并通过主成分分析法对不同处理进行综合评价。结果表明：在相同的氮肥条件下,保水剂与氮肥混施提高了叶片叶绿素含量,提高了净光合速率（P_n）、蒸腾速率（T_r）、气孔导度（G_s）、胞间二氧化碳浓度（C_i）等光合参数及初始荧光（F_o）、最大荧光（F_m）、可变荧光（F_v）、潜在活性（F_v/F_o）、最大光化学效率（F_v/F_m）实际光化学产量（Φ_PSⅡ）、光合电子传递速率（ETR）、光化学猝灭系数（qP）和非光化学猝灭系数（qN）等荧光参数,降低了水分利用效率（WUE）,说明采用保水剂和氮肥混施能够提高氮肥利用率。主成分分析综合得分CK、A、B、C、D、E、F分别为-12.57、-8.15、-3.89、3.15、0.12、10.02、11.32。综合得分F最高,即保水剂（180 g/丛）与氮肥（450 g/丛）组合最优。

Effects of Water-retaining Agent and Nitrogen Fertilizer on Photosynthetic Characteristics and Chlorophyll Fluorescence Characteristics of Bambusa tuldoides cv. Swolleninternode

In this study,the effects of nitrogen fertilizer(150,300 and 450 g/cluster)and water-retaining agent(180 g/cluster)combined with nitrogen fertilizer(150,300 and 450 g/cluster)on chlorophyll,photosynthetic parameters and chlorophyll fluorescence parameters of three-year-old Bambusa tuldoides cv.Swolleninternode were studied,and the comprehensive evaluation of different treatments was carried out by principal component analysis.The results showed that chlorophyll content increased with the increase of nitrogen fertilizer,and the content of water-retaining agent mixed with nitrogen fertilizer was lower than that of nitrogen fertilizer alone.Net photosynthetic rate(Pn),transpiration rate(Tr),stomatal conductance(Gs),intercellular carbon dioxide concentration(Ci),water use efficiency(WUE)of the leaf increased with the increase of nitrogen fertilizer,and the value of photosynthetic parameters was higher under the application of water retaining agent than that under the application of nitrogen fertilizer alone.The initial fluorescence(Fo)of all fertilization treatments was higher than that of CK.With the increase of nitrogen fertilizer,the maximum fluorescence(Fm),variable fluorescence(Fv),potential activity(Fv/Fo),maximum photochemical efficiency(Fv/Fm),actual photochemical yield(PS II),photosynthetic electron transfer rate(ETR),photochemical quenching coefficient(qP)and non-photochemical quenching coefficient(qN)also increased gradually,while under the same amount of nitrogen fertilizer,the values increased with the increase of water retaining agent.The principal component analysis scores of CK,A,B,C,D,E and F was-12.57,-8.15,-3.89,3.15,0.12,10.02 and 11.32,respectively.Therefore,the application of nitrogen fertilizer promoted the growth of B.tuldoides cv.Swolleninternode,and the effect of adding water-retaining agent was better than that of applying nitrogen fertilizer alone.The comprehensive score F was the highest,meaning the combination of water-retaining agent(180 g/cluster)and nitrogen fertilizer(450 g/cluster)was the best.