硝铵态氮不同配比对葡萄新梢生长和叶片光合特性的影响

Effects of different NO_3^--N/NH_4^+-N ratios on shoot growth and leaf photosynthetic characteristics of Cabernet Sauvignon(Vitis vinifera)

【目的】研究硝态氮与铵态氮不同配比对赤霞珠葡萄新梢生长和叶片光合特性的影响,以期为葡萄园合理施用氮肥提供一定的理论依据。【方法】以欧亚种(Vitis vinifera)酿酒葡萄赤霞珠(Cabernet Sauvignon)为供试材料,采用盆栽试验,在根系施用不同配比的硝态氮和铵态氮(NO_3^--N/NH_4^+-N分别为100:0,75:25,50:50和0:100,供氮(N)总量保持一致,均为9.45g/株),分析硝铵态氮不同配比对葡萄新梢生长和叶片光合特性的影响。【结果】与NO_3^--N/NH_4^+-N分别为100:0,0:100处理相比,NO_3^--N/NH_4^+-N分别为75:25,50:50的处理总体上均明显提高了赤霞珠葡萄的新梢长度、节间长度、节间粗度和叶面积平均增长量,增加了叶片中叶绿素、游离氨基酸和可溶性蛋白质的含量。无论是在坐果期还是果实转色期,与NO_3^--N/NH_4^+-N分别为100:0和0:100处理相比,NO_3^--N/NH_4^+-N分别为75:25和50:50的处理使叶片光系统Ⅱ(PSⅡ)的最大光合效率(Fv/Fm)、实际光合效率(ΦPSⅡ)、光化学淬灭(qP)提高,非光化学淬灭(NPQ)降低。NO_3^--N/NH_4^+-N分别为75:25和50:50处理葡萄叶片的净光合速率(P_n)、胞间CO_2浓度(Ci)、气孔导度(Gs)和蒸腾速率(Tr)总体显著高于NO_3^--N/NH_4^+-N分别为100:0和0:100处理。【结论】NO_3^--N与NH_4^+-N配施能促进赤霞珠葡萄新梢和叶片的生长,提高葡萄叶片光合特性,其中NO_3^--N/NH_4^+-N为75:25处理的效果较优。

【Objective】This study evaluated the effects of nitrogen fertilizer application with different NH_4~＋-N/NO_3^--N ratios to roots on shoot growth and leaf photosynthetic characteristics of Vitis vinifera cv.Cabernet sauvignon to provide basis for reasonable application of nitrogen in vineyard.【Method】The experiment had four treatments including NO_3^--N/NH_4~＋-N ratios of 100：0,75：25,50：50 and 0：100 with the same total nitrogen rate of 9.45g/plant.【Result】The treatments with NO_3^--N/NH_4~＋-N ratios of 75：25 and 50：50 generally increased the average growth of shoot length,internode length,shoot diameter and leaf area of Cabernet sauvignon compared to the treatments with NO_3^--N/NH_4~＋-N ratios of 100：0 and 0：100.The treatments with NO_3^--N/NH_4~＋-N ratios of 75：25 and 50：50 also promoted the contents of chlorophyll,amino acid and soluble protein in leaves of Cabernet sauvignon.The treatments with NO_3^--N/NH_4~＋-N ratios of 75：25 and 50：50 were beneficial to increase Fv/Fm,ΦPSⅡ and qP and reduce NPQof leaf PSII at fruit setting and color conversion stages.In general,the P_n,Ci,Gs and Tr of grape leaves in the treatments with NO_3^--N/NH_4~＋-N ratios of 75：25 and 50：50 were significantly higher than those in treatments of 100：0 and 0：100.【Conclusion】Mixed nitrogen treatments of nitrate and ammonium increased growth of shoot and leaf and photosynthetic characteristics of Cabernet sauvignon,and the treatment with NO_3^--N/NH_4~＋-N ratio of 75：25 is recommended.