【作者】 卞景阳；

【导师】 张文忠； 张佳华；

【作者基本信息】 沈阳农业大学 ， 作物学， 2013， 博士

【摘要】 CO2浓度是影响水稻生产的重要环境因子。IPCC(政府间气候变化专门委员会)报告显示,大气CO2浓度呈现快速增长的趋势,预测到本世纪中叶将达到550μmol·mol-1.这种环境的加剧变化将对植物生态系统产生重要的影响。本研究以OTC(开顶式气室)为试验手段,寒地粳稻为研究对象,设定多个CO2浓度,研究CO2浓度对寒地粳稻产量、生育特性和光合生理的影响。主要结果如下：1.随着CO2浓度的增加,寒地粳稻总干物质积累量增加,其中根、茎、穗的干物质量增加,叶片干物质量先增加后减少。不同器官对CO2浓度响应的差异,导致水稻根冠比、茎叶比升高,谷草比和收获指数下降。随着CO2浓度的增加,水稻产量增加,其中有效穗数和主穗2次枝梗库容的增加是产量增加的主要因素。高CO2浓度较CK增产15.6%,中CO2浓度较CK增产,但差异不显著；产量构成中有效穗数、着粒密度、穗粒数增加,但千粒重显著下降。根据不同部位的稻穗和穗部结构对产量增加的贡献率,从大到小依次是：有效穗数、主穗的2次枝梗数、2次枝梗平均实粒数、1次枝梗平均实粒数。2.随着CO2浓度增加,寒地粳稻生育进程加快。叶龄指数和抽穗期提前,抽穗速度加快,扬花时间提前,灌浆速率提高。高、中CO2浓度较CK,抽穗期分别提前72h、21h；高CO2浓度较CK,平均灌浆速率提高、高速灌浆的时间缩短,并提前2d达到最大灌浆速率,最大灌浆速率提高11.50%,其中劣势粒较优势粒提高明显。随着CO2浓度增加,寒地粳稻叶面积指数先增加后减少；单叶叶面积显著减少,比叶重显著增加,叶龄越大影响越显著,营养生长期显著抑制叶宽,生殖生长期显著抑制叶长。3.随着C02浓度的增加,光合速率和胞间CO2浓度提高,气孔导度、蒸腾速率降低,光合参数对浓度变化的响应存在短期和长期的效应,在光合速率参数中,除暗呼吸速率提高外,其它参数都向着有利于光合生产率提高的方向变化。高CO2浓度处理的平均光合生产率显著高于中CO2浓度和CK,增幅分别为25.96%、19.00%,平均光合生产率除灌浆期外,其它时期随处理时间延长逐渐减少,灌浆期最大；随着CO2浓度增加,最大净光合速率、暗呼吸、初始量子效率、光饱和点逐渐增加,光补偿点逐渐减少；最大净光合速率在CO2浓度在380-680μmol-mol-1时,呈现加速提高的趋势,CO2浓度超过680μmol·mol-1后增速逐渐减小。4.随着CO2浓度增加,叶片微观结构发生改变,单位面积细胞数量增多,不同细胞参数差异明显,对叶片背面影响显著。随CO2浓度增加,单元内硅栓细胞带和气孔带间距离极显著增加；不同细胞带上细胞排列更加紧密,S型排列气孔带数量增加。CO2浓度增加,硅、栓细胞长度增加、宽度变小,硅栓带上单位面积细胞数量显著减小,尤其是栓细胞上镶嵌乳突面积极显著减少；叶片背面气孔密度(SD)略有下降,气孔指数(SI)显著降低,气孔器、保卫细胞的面积、周长,长度极显著增大,保卫细胞宽度和乳突数量极显著减小；叶片腹面气孔器宽度和乳突数量极显著减小,面积、周长显著减小。随着CO2浓度增加,叶绿体形状由原来的近梭形、椭圆形变成近圆形,淀粉粒体积变大,叶绿体及其基粒和类囊体膜完好无损,叶绿体厚度变薄,基粒的垛迭程度和宽度增加。5.随着CO2浓度的增加,寒地粳稻品种产量提高,有效分蘖增加是产量增加的主要因素,不同品种对CO2的响应差异显著。研究表明,随着CO2浓度的增加,株高、结实率、千粒重和有效分蘖呈增加趋势：穗长和穗粒数在品种间变化趋势不一致。不同熟期品种产量增幅比较,早熟品种>中熟品种>晚熟品种。同熟期品种产量结构变化特征表明,中熟品种产量性状对CO2浓度变化的响应趋势较一致,晚熟品种差异较大。更多还原

【Abstract】 Atmospheric CO2concentration is important environmental factor for rice production. IPCC’s reports showed a increasing trend for CO2concentration, which predicted the concentration will hit up to550μmol-mol-1in this mid of century. This condition will accelerate the impact of elevated CO2on ecosystem of plants, ecosystem. OTC (open top chamber) is applied in this study. Japonica rice of cold region will be used to research the effects of different CO2concentration on the yield, growth character and photosynthetic physiology of Japonica rice in cold region. The results showed:1. Elevated CO2induced a increase of dry matter for root, stem and grain, and for single leaf increase at first and decrease. Differences from different organs makes the root-shoot ratio and stem-leaf ratio increase, grain-straw ratio and harvest index decrease. CO2concentration increasing makes the productivity increase, valid tiller number, sub-racbis in main stem are the main factors. The productivity of CK increased15.6%under elevated CO2treatment, but not significant effects occurred under middle level of CO2concentration. Tiller number, panicle intensity, number of panicle per tiller increased, but thousand grain weight decreased significantly. The changes of productivity on sensitivity of CO2in turn were:valid tiller number, sub-rachis in main stem, averaged valid grain at sub-rachis, valid grain at first rachis according to different position responsible for changes of productivity and sensitivity of tiller structure.2. Elevated CO2induced growth process become faster, leaf-age index and heading date earlier, heading faster, flowering period earlier, filling speed faster. The heading stage shifted to72h,21h under high concentration and middle CO2compared to CK, elevated CO2accelerate averaged graining ratio, shorter high-speed graining, and2d ahead of heading stage reached up to maximum graining, the maximum graining speed increased11.5%, some at superior position increase obviously. Elevated CO2induced leaf-area index increase at first and then decrease, single leaf area reduce significantly more than leaf weight which is according to leaf age. 3. Elevated CO2induced photosynthetic rates and rnal CO2increased, stomatal conductance and transpiration decrease. Response from photosynthetic index has long term and short term effects to CO2concentration, all parameters change according to photosynthetic production increase except dark respiration rate. Averaged productivity of photosynthesis under higher CO2concentration treatments increased25.96%and19.00%under highest and middle concentration, respectively. Maximum net photosynthetic rates, dark respiration, initial quantum efficiency, saturated point of light increased, but compensate point of light decreased, maximum of nct photosynthetic rates between380-680μmol-mol-1exhibited a faster trends, after680μmol-mol-1, the speed became slower.4. Elevated CO2induced microstructure change:unit cell number increase, cell index differ obviously and impact leaf back significantly. Distance between silicon cell band cork and cork cell band increase significantly; Different cells arrange more intensely, S stomata band number increase. Elevated CO2induced the increase of silicon and cork in foliar silicon band, but the width became smaller, cellular unit areas along silicon cork band were significantly decreased, especially for cork cell mount in mastoid numbers, stoma density at foliar back showed slightly decrease, somatal index decreased significant, stoma and areas of guard cells, circumference and length increased significantly, width of guard cells and numbers of mastoid process decreased significantly. Width of stoma at segmental venter decreased significantly, as well as area, circumference.During CO2increased, Shapes of chloroplast shifted from ellipse to circular, volume of starch grain became bigger and occupying into chloroplast, foliar chloroplast and its granum and thylakoid membrane have no difference, thickness of chloroplast decreased, but granum superposition and width increased.5. Elevated CO2induced productivity cold land japonica rice increase, the main factor is increase of effective tiller number, there are big differences among different cultivars. By comparing the cultivars of different maturity, the order from high to low for productivity is early>middle> later maturity. The results by analyzing the effects of CO2concentration on productivity of cultivars at same period maturity showed, the cultivars at middle maturity stages in response to CO? showed same trends, but there are big differences among late cultivars.更多还原