开放式空气CO2浓度升高对水稻根系形态的影响

在FACE（free-air carbon dioxide enrichment）技术平台上，采用水培的研究方法，观测了大气CO2浓度升高和两种氮水平下水稻根系形态的变化。结果表明，在水稻各生育期，CO2浓度升高都极显著增加了根干质量，且主要增加于根粗为2．0～2．5mm／n的部位。根系形态的各项指标均对高CO2浓度有积极的响应，在抽穗期尤为明显；N处理的差异很明显，低氮条件下根系表现为根长、根尖数和根表面积增加，常氮条件下根粗和发根数增加。各生育期的根冠比在高CO2浓度下极显著增加，尤其在LN处理下。水稻从分蘖期到抽穗期，因地上部分的增幅大，根冠比表现为逐渐降低的趋势。

Effects of free-air CO2 enrichment on root morphology of rice

In this paper the effects of elevated CO2 and different nitrogen supply on root morphology of rice were examined. The results showed that CO2 enrichment significantly increased root biomass during the whole growth season. CO2 and Nitrogen treat- ments changed root morphology. Root growth showed a positive response to CO2 enrichment, especially in the heading. Root length, number of root tips, total root surface increased at low nitrogen, while root width, number of adventitious roots increased at normal nitrogen. R/S (root/shoot) increased significantly under CO2 enrichment, especially at low nitrogen (P<0.001). The ratio of R/S de- creased with increasing growth of rice,owing to faster increase of shoot biomass than the root at later stages.