【作者】 刘红江；

【导师】 王余龙； 黄建晔；

【作者基本信息】 扬州大学 ， 农产品安全与环境， 2008， 博士

【摘要】 全球大气中CO₂浓度不断升高已是不争的事实。据估计到2050年前后,大气CO₂浓度将增至450-550μmol·mol^-1。大气CO₂浓度的不断升高将引起全球气候明显变化,并对农作物生产产生重大影响。前人已经研究了FACE对粳型水稻品种产量及其构成因素、物质生产与分配、养分吸收利用以及根系发育等的影响。为了明确FACE对在我国水稻生产中具有重要地位,且杂种优势强、环境适应强、产量潜力大的杂交籼稻的影响,本研究利用中日合作建立在我国江苏省江都市的农田FACE研究平台（32°35’5’’N,119°42’E）,以三系杂交籼稻汕优63为供试品种,设计比目前大气CO₂浓度（对照）高200μmol·mol^-1的FACE对其进行了比较系统的研究,以期为未来大气CO₂浓度升高条件下我国水稻品种选育和应用、栽培技术的制订提供实验依据。主要研究结果如下,1.FACE使汕优63成熟期株高比AMB提高6.7%,达极显著水平;FACE对汕优63全生育期日数无显著影响;FACE使汕优63产量平均比AMB增加34.1%,其中2004、2005、2006年分别增加42.4%、27.3%和31.2%,均达极显著水平;CO₂×Y（年度）的互作效应对产量的影响达显著水平;FACE使汕优63单位面积穗数、每穗颖花数、单位面积颖花量、结实率和千粒重平均比AMB增加10.3%、10.3%、21.7%、4.9%和4.3%,均达显著或极显著水平;N处理对汕优63产量和产量构成因素的影响均未达显著水平,但N×Y对汕优63单位面积的穗数、颖花量以及产量均有显著互作效应。2.两季平均,FACE使汕优63移栽-分蘖期、分蘖-拔节期、拔节-抽穗期和抽穗-成熟期干物质生产量分别比AMB增加了39%、20%、32%和41%,结果使成熟期生物产量显著增加（+33%）;与干物质生产量相比,汕优63平均叶面积指数（LAI）和净同化率（NAR）对CO₂的响应有相似的季节性变化趋势,但LAI的响应值明显大于NAR;FACE使汕优63不同生育时期叶片和稻穗占地上部干重的比例下降,而使茎鞘占地上部干重的比例明显增加;FACE使汕优63抽穗和成熟期茎鞘中可溶性碳水化合物的含有率和积累量均显著增加;三系杂交籼稻汕优63成熟期生物产量以及不同生育阶段平均LAI、NAR和干物质生产量对FACE的响应与粳稻品种存在明显差异,而干物质分配差异较小。3.FACE使汕优63各生育时期稻株含N率显著下降,使各生育时期N素吸收量显著增加,生育中期的增幅明显小于生育前、后期;FACE对汕优63 N素在不同器官中分配比例无明显影响;FACE使汕优63不同生育期N素干物质生产效率极显著提高,使N素籽粒效率显著提高,但对N素收获指数无显著影响;增施N肥,使汕优63不同生育时期的植株N素含量和吸N量均得到显著或极显著的增加,使N素干物质生产效率和N素籽粒效率下降;CO₂×Y、N×Y对植株含N率、吸N量的影响有互作效应,FACE使汕优63稻株含N率显著下降;使N素吸收量、N素干物质生产效率、N素籽粒效率显著提高。4.FACE使汕优63各生育时期稻株含P率极显著提高,使各生育时期P素吸收量极显著增加,生育中期的增幅略小于生育前、后期;FACE使汕优63抽穗后P素在茎鞘中的分配比例显著增加,穗中的分配比例显著下降,对抽穗前P素在叶片、茎鞘中的分配比例均无显著影响;FACE使汕优63不同生育期P素干物质生产效率极显著下降,使P素籽粒生产效率和P素收获指数亦均极显著下降;增施N肥,使汕优63大多数生育时期的植株P素含量和吸P量得到显著或极显著的增加,使大多数生育时期P素干物质生产效率下降,使P素籽生产粒效率和收获指数显著下降;CO₂×N、CO₂×Y对植株含P率、吸P量的影响有互作效应,FACE使汕优63稻株含P率、P素吸收量显著提高;使P素干物质生产效率、P素籽粒效率显著下降。5.FACE使汕优63分蘖期、拔节期、抽穗期每穴的不定根数、不定根总长度、根系体积以及根干重均极显著大于AMB;FACE使汕优63抽穗期每穴不定根数和每穴根体积极显著增加,主要是由于FACE使汕优63有效分蘖期间和无效分蘖期间每穴不定根数和每穴根体积大幅度增加;FACE使汕优63抽穗期每穴不定根总长度极显著增加,主要是由于FACE使汕优63有效分蘖期间、无效分蘖期间,拔节长穗期间每穴不定根总长度均大幅度增长;FACE使汕优63抽穗期每穴根干重极显著大于AMB,主要是由于FACE使汕优63拔节长穗期间每穴根干重的增长量大幅度增加;FACE使汕优63抽穗期每条不定根长极显著大于对照,是因为FACE使汕优63不同生育阶段每条不定根长的生长量均明显增加。6.FACE使汕优63不同生育时期单位干重根系的总吸收面积、活跃吸收面积、α-萘胺氧化量等根系活性指标均极显著小于对照。由于FACE促进汕优63根系发生量的大幅度增加,因此够苗期、拔节期其单穴根系活性与AMB多无明显差异,到抽穗期FACE使单穴根系活性显著大于AMB;拔节期、抽穗期汕优63每穴的不定根数、不定根总长度、根系体积、根干重与单位干重根系活性关系密切,根量越大单位干重根系活性越低;不同生育时期汕优63植株含氮率与单位干重的根系活性多呈正相关,植株碳氮比与单位干重的根系活性多呈负相关;FACE使汕优63根系生长量大、植株含氮率低、碳氮比高等可能是造成其单位干重根系活性低于AMB的重要原因。更多还原

【Abstract】 It is reported that Global atmospheric CO₂ concentration is increasing continually. And it is projected to reach levels of 450～550μmol·mol^-1 within year 2050. The enhancement of atmospheric CO₂ concentration commonly caused the climate change and affected the agriculture crops production. The effects of FACE on yield and yield components, biomass production and distribution, nutrient uptake and efficiency, roots of Japonica rice have been reported. This study was carried out in the platform for FACE study, located in Jiangdu （31°37’N,120°28’E）, China, using three-line hybrid indica rice shanyou 63 as tested rice cultivar. The CO₂ concentration in FACE treatment was 570μmol·mol^-1, with 370μmol·mol^-1 as ambient （AMB）. The main purpose of the experiment was to study the effects of elevated CO₂ concentration on three-line hybrid indica rice production. Results showed as follows:（1） Compared to ambient [CO₂], FACE increased plant height at maturity of Shanyou 63 by 6.7% on average, the effect reaching significant level （P < 0.01）, however, no CO₂ effect was observed on the whole growth duration of Shanyou 63. On average, FACE increased the grain yield of Shanyou 63 significantly （P < 0.01）, with an average increase of 34.8% across the three years （42.4%、27.3% and 31.2% in 2001, 2002 and 2003, respectively）. The year effect and the interaction between [CO₂]×year were significant （P < 0.05 or P < 0.01） for grain yield; FACE increased yield components of Shanyou 63 significantly （P < 0.05 or P < 0.01）, averaging 10.3%, 10.3%, 21.7%, 4.9% and 4.3% for panicle number per unit area, spikelet number per panicle, spikelet number per unit area, filled grain percentage and 1000-grain weight, respectively. N effect was not significant on yield and its components of Shanyou 63, while its interaction with [CO₂] was significant for panicle number, spikelet number and grain yield per unit area.（2） Across the two growing seasons, rice DM production under FACE was significantly enhanced by 39, 20, 32 and 41% during the growth periods from transplanting to tillering, tillering to jointing, jointing to heading and heading to grain maturity, respectively. As a result, the final total biomass at maturety was increased by 33% on average. In general, seasonal changes in crop response to FACE in both leaf area index （LAI） and net assimilation rate （NAR） followed a similar pattern to that of the DM production, with the degree of response much larger in LAI than NAR. Under FACE the leaves and spikes decreased significantly in proportion to the total above-ground DM over the season, while the stems showed an opposite trend. FACE significantly increased the content （%） and amount of soluble sugar and starch in stems and sheaths at heading and grain maturity. Huge differences existed between the three-line indica hybrid rice cultivar and japonica rice cultivar with respect to the responses of final DM accumulation at maturity, as well as mean LAI and NAR, and DM production during the different growth periods, while differences on dry matter distribution were small.（3） Compared with AMB, FACE significantly decreased N concentration in rice plant of Shanyou 63 over the season, FACE significantly increased nitrogen accumulation in rice plant, and the increasing rate at the middle growth stage was less than that at the early and late growth stage. FACE had no obvious effect on nitrogen allocation pattern of Shanyou 63 over the season. FACE treatment resulted in the significant increase in N use efficiency for biomass （NUEp） over the season and in N use efficiency for grain yield （NUEg） at grain maturity, but no CO₂ effect was observed on nitrogen harvest index （NHI）. Nitrogen concentration and accumulation at different growth stages of Shanyou 63 increased with increasing N supply （P < 0.05 or 0.01）, but NUEp and NUEg showed the opposite trends. Significant interactions between [CO₂]×year and N×year were observed for N concentration and accumulation. FACE decreased N concentration, increased N uptake, NUEp and NUEg at different growth stages of Shanyou 63, but no CO₂ effect was detected on N allocation（4） Compared with AMB, FACE significantly increased P concentration in rice plant of Shanyou 63 over the season, FACE significantly increased phosphorus accumulation in rice plant, and the increasing rate at the middle growth stage was less than that at the early and late growth stage. Before heading, FACE had no obvious effect on phosphorus allocation pattern of Shanyou 63, but after heading, it made the proportion of phosphorus allocation in leaves significant increased, the phosphorus allocation in spikes significant decreased. Under FACE treatment, P use efficiency for biomass （PUEp） over the season, P use efficiency for grain yield （PUEg） at grain maturity, and phosphorus harvest index （PHI） were significantly decreased. Phosphorus concentration and accumulation at majority growth stages of Shanyou 63 increased with increasing N supply （P < 0.05 or 0.01）, but PUEp and PUEg showed the opposite trends. Significant interactions between [CO₂]×N and [CO₂]×year were observed for P concentration and accumulation. FACE increased P concentration and P uptake, decreased PUEp and PUEg at different growth stages of Shanyou 63.（5） FACE treatment increased the number of adventitious roots per hole, the length of adventitious roots per hole, the roots volume per hole, the dry weight of roots per hole significantly of Shanyou 63 at tillering, jointing and heading stages. the number of adventitious roots per hole and the roots volume per hole under FACE were significantly higher than those under AMB at heading stage, which was chiefly resulted from the larger increment of those root traits under FACE during effective-tillering and unproductive-tillering period. The length of adventitious roots per hole under FACE was significantly higher than that under AMB at heading stage, which was chiefly caused by the still larger increment of the length of adventitious roots per hole under FACE before heading. the dry weight of roots per hole under FACE was significantly higher than that under AMB at heading stage due to FACE substantially increased the dry weight of roots per hole during stem elongating and panicle bearing period. the length of per adventitious root under FACE was significantly higher than that under AMB at heading stage, which was chiefly resulted from the still larger increment of the length of per adventitious root under FACE before heading.（6） The total absorption area per unit dry weight of root, the active absorption area per unit dry weight of root and the amount ofα-NA per unit dry weight of root of shanyou63 under FACE were significantly higher than those under AMB at different growth stages. While FACE made larger increment of rice root, which resulted in no significant difference of root activity per hole between FACE and AMB at tillering and jointing stages, but FACE significantly increased root activity per hole at heading stage. Root activity per unit dry weight of root negatively correlated with the number of adventitious roots per plant, total length of adventitious roots per plant, roots volume and dry weight of root at jointing and heading stages. The larger the root productions, the lower the root activity per unit dry weight. For the most part,root activity per unit dry weight of root positively correlated with N content of rice plant, and negatively correlated with the content of soluble carbohydrates in stem and sheath and C/N ratio. The largeness of biomass accumulated, lower N content in rice plant and higher C/N ratio appear to be the primary causes of significant decrement of root activity per unit dry weight of root under FACE.更多还原