为构建水稻高产高效节水栽培技术模式,采用裂区试验设计方法研究了氮密互作对双季晚稻丰源优299光合特性及产量的影响.结果表明:不同氮密处理水稻叶片净光合速率、气孔导度、胞间CO2浓度和蒸腾速率差异性显著;分蘖盛期光合速率最高;施氮量180 kg/hm2时分蘖盛期和乳熟期净光合速率最高,分别比其他施氮处理高6.43％～ 10.01％和3.92％～ 70.51％;分蘖盛期净光合速率随密度的增加呈现线性降低的趋势,栽植密度30万穴/hm2较其他处理低5.04％～6.73％,孕穗期和乳熟期净光合速率规律性不明显,抽穗期表现为密度越高净光合速率越强的趋势,低密处理显著低于高密处理,低4.45％ ～7.97％;动态变化趋势表现为:净光合速率先降低后升高再降低、气孔导度先升高后降低、胞间CO2浓度先升高后降低再升高、蒸腾速率则呈线性下降;水稻经济产量与水稻生育前期和后期光合作用呈正相关,生育后期表现为极显著相关,与水稻生育中期光合作用呈负相关.因此,通过合理氮密调控,提高水稻生育前期与后期的光合作用,维持生育中期光合作用大小,是提高水稻经济产量的重要途径.%For building a pattern of high yield,high efficiency and water-saving planting technology of rice,a split-plot design experiment was conducted to explore the influences of interaction between nitrogen and density on photosynthetic characteristics and the yield of the late rice Fengyuanyou 299.Significant differences between net photosynthetic rate,conductance to H2O,intercellular CO2 concentration and transpiration rate of different nitrogen and density in rice leaf were showed and the highest photosynthetic rate was observed at the tillering stage.The net photosynthetic rate at tillering stage and milky stage both showed the highest parameters when the amount of nitrogen fertilizer was 180 kg/hm2,and had about 6.43％-10.01％ and 3.92％-70.51％ higher than other treatments respectively.Tillering stage net photosynthetic rate reduced linearly with increasing density,and had about 5.04％-6.73％ lower than other treatment at the planting density of 300 thousand/hm2 points,there were no significant differences at booting stage and milky stage,and the higher density was responsible for the stronger net photosynthetic rate at the heading,the regularity of net photosynthetic rate had significantly lower about 4.45％-7.97％ in the low-density processing than in the high-density processing.The trends of its dynamic performance showed as follows:The net photosynthetic rate was increased at first,then decreased and reduced eventually;conductance to H2O was declined at first and then ascended;the intercellular CO2 concentration was increased at first,then reduced and elevated after that;transpiration rate was declined straightly.The results showed that a positive correlation had existed between economic yield and the photosynthesis in the early rice and the late rice growth stages,especially had extremely significant correlation at the late growth stage and had negative correlation at the mid growth stage of the rice respectively.So it~ an important way to improve the economic yield of rice by building a reasonable regulation of nitrogen and density,improving the photosynthesis in the early and late growth of rice and keeping the photosynthesis in the mid growth stage of rice.
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