开放式空气CO2增高对水稻物质生产与分配的影响

在大田栽培条件下，研究开放式空气CO2增加(FACE)200μmol·mol^-1的处理对水稻物质生产与分配的影响．结果表明，FACE处理使移栽至抽穗后20d的干物质积累量显著增加，使抽穗后20d至成熟期的干物质生产量显著减少，生物产量显著提高．移栽至抽穗期的干物质积累量增加是由于叶面积系数和净同化率共同提高所致；抽穗期至抽穗后20d的干物质积累量增加主要是由于叶面积系数的增加所致；抽穗后20d至成熟期的干物质生产量减少主要是由于净同化率的下降所造成．提高茎鞘占全株干物重的比例，降低叶片占全株干物重的比例，对穗占全株干物重的比例无显著影响，能显著提高水稻抽穗期茎鞘中可溶性糖、淀粉的含有率和含量，提高FACE处理的生物产量能极显著提高水稻产量(r＝0．7825)．

Effect of free-air CO2 enrichment on biomass accumulation and distribution in rice

Investigation on the effect of free-air CO2 enrichment (FACE) on biomass accumulation and distribution in different parts of rice plant treated with 200 mumol.mol-1 CO2 elevation under field condition showed that the dry matter accumulated from transplanting to 20th day after heading and the total biomass increased significantly, while the dry mater accumulated from 20th day after heading to maturity was significantly depressed under FACE treatment. The enhancement of both leaf area index (LAI) and net assimilation rate (NAR) under FACE treatment resulted in the increase of dry matter accumulated from transplanting to heading, while the dominant reason for the increase of dry matter accumulated during 20 days after heading was the slowed decline of LAI. The decline of dry matter accumulated from 20th day to maturity was mainly caused by the decrease of NAR. The percentage of dry matter distributed in stem and sheath increased under FACE treatment, while that in leaf decreased, and that in panicle showed no significant change. The content (%) and amount of soluble sugar and starch in stem and sheath at heading was significantly elevated under FACE. The grain yield of rice under FACE treatment could be significantly improved by raising biomass.