CO_2浓度升高和不同灌溉量对东北玉米光合特性及产量的影响  

Effects of elevated CO_2 and different irrigation on photosynthetic parameters and yield of maize in Northeast China

作　　者：孟凡超[1,2] 张佳华[1] 郝翠[1] 周正明[1] 李辉[3] 刘丹[1] 王凯[4] 张华[4] 

机构地区：[1]中国气象科学研究院生态环境与农业气象研究所,北京100081 [2]南京信息工程大学大气科学学院,南京210044 [3]中国科学院大学地球科学学院,北京100049 [4]长江大学,武汉434023

出　　处：《生态学报》2015年第7期2126-2135,共10页Acta Ecologica Sinica

基　　金：国家重点基础研究发展计划项目课题(2010CB951302)

摘　　要：CO2和水分是植物光合作用的重要底物,大气CO2浓度升高或水分变化影响植物光合作用。玉米是重要的C4植物,目前已成为我国第一大作物。我国东北地区的玉米产量占全国玉米产量的1/3左右,对确保国家的粮食安全具有重要作用。但是,关于CO2浓度升高或水分变化共同作用对东北玉米的光合速率、水分利用效率和产量影响的研究甚少。基于开顶式生长箱(OTCs),模拟研究了CO2浓度变化(390、450、550μmol/mol)和降水变化(0、+15%(以试验地锦州1981—2010年6、7、8月月平均降水量88.7,153.9 mm和139.8 mm为基准))共同作用对玉米光合特性及产量的影响。以玉米品种丹玉39为材料,利用直角双曲线修正模型对6个处理(C550W+15%、C550W0、C450W+15%、C450W0、C390W+15%和C390W0)的光响应曲线进行了拟合。结果表明:在CO2浓度升高和灌溉的共同作用下,玉米叶片净光合速率(Pn)升高,且灌溉作用大于高CO2浓度作用;而蒸腾速率(Tr)则下降,使水分利用效率(WUE)升高。CO2浓度升高使气孔导度(Gs)降低,灌溉则使之升高,但灌溉的作用小于高CO2浓度作用;胞间CO2浓度(Ci)随CO2浓度增加而升高,灌溉对其影响不明显。高CO2浓度和灌溉共同作用下光响应参数差异明显。CO2浓度升高增加了最大净光合速率(Pnmax)和光饱和点(LSP),灌溉亦然;CO2浓度升高使得光补偿点(LCP)、光补偿点量子效率(φc)和暗呼吸速率(Rd)的灌溉处理和自然降水处理的差距变小。390、450、550μmol/mol CO2浓度下的灌溉处理与自然降水处理相比,叶面积分别增加了11.56%、3.31%和0.45%,干物质积累量分别增加了14.69%、8.09%和1.01%,最终使产量分别增加了10.47%、12.07%和8.96%。可见,在高CO2浓度下,适量的灌溉对玉米的整个光合作用过程起到了促进作用,最终表现为籽粒产量的增加。为研究者评估气候变化对中国东北地区作物光合能力和产量的影响及决策者调整适应气CO2 and water are important substrates for plant photosynthesis. Changes in COs concentration or soil water will lead to corresponding changes in the photosynthetic characteristics of plant. Maize （Zea mays L. ） is an important C4-plant and has become the first cultivated crop of China. Maize yield in Northeast China is accounting for about 1/3 of the national total maize yield, and having a central role in ensuring the food security of county. However, the combined effects of COs concentration and water status on photosynthesis efficiency, water use efficiency and yield of maize in Northeast China are not well understood. Maize variety Danyu39 was grown in the open top chambers （OTCs）to study the effects of contrasting CO2 concentrations （390,450 p^mol/mol and 550 p^mo[/mol） and increasing precipitation（0 and ＋ 15%, which based on the 6,7,8 month average monthly precipitation, i.e. 88.7, 153.9 mm and 139.8 mm during 1981--2010 in Jinzhou）on photosynthetic characteristics and crop yield. By using LI-6400 portable photosynthesis system, the photosynthetic parameters data were measured and the modified rectangular hyperbolic model was used to fit the light response curves of 6 treatments（ C550 W＋15%, C550 W0, C450 W＋15%, C450 W0, C390 W＋15% and C390 W0 ）. The results showed that maize leaf net photosynthetic rate （ Pn ） increased under the conditions of increasing CO2 concentration and irrigation, respectively. Moreover, the irrigation effect was greater than elevated CO2 concentration. With transpiration rate （ Tr） decreasing, water use efficiency （ WUE ） increased greatly. Stomatal conductance （ Gs ） showed decreased trend with the increase of COs concentration, but Gs increased with irrigation, and the effect of irrigation was less than elevated COs. Although the intercellular CO2 concentration （ Ci ） increased significantly by the influence of elevated CO2 concentration, but there were no significant effects by irrigation. Light response parameters were obviously

关 键 词：CO2浓度升高 灌溉 直角双曲线修正模型 光合参数 产量 玉米 

分 类 号：S513[农业科学—作物学]