Two cultivars of soybean (Glycine max cv. Bragg and PK 472) were subjected to elevated concentrations of CO(2) (600 &mgr;l l(-1)) and/or SO(2) (0.06 &mgr;l l(-1)), for 8 h from germination to grain maturity in open top chambers under field conditions to assess the modification in response to SO(2) exposure resulting form CO(2) enrichment. Exposure to SO(2) alone resulted in reductions in plant growth, biomass and yield, as well as declines in foliar starch and protein content in both the cultivars of soybean. Elevated CO(2) stimulated plant growth, yield and enhanced foliar starch content, photosynthesis and WUE in both the cultivars. In plants exposed to the combination of elevated CO(2)+SO(2), the adverse influence of SO(2) was mitigated by CO(2) enrichment. This effect was considered to result from the provision of extra carbon sources required for repair and detoxification processes and a reduction in SO(2) uptake through reduction in stomatal conductance. PK 472 exhibited greater sensitivity to SO(2) than Bragg. PK 472 also showed greater stimulation of yield under CO(2)+SO(2) treatment than Bragg.

中文翻译：

---

CO2 升高对两个大豆品种对二氧化硫敏感性的影响

大豆的两个品种（甘氨酸最大值 cv. Bragg 和 PK 472）受到高浓度的 CO(2) (600 &mgr;ll(-1)) 和/或 SO(2) (0.06 &mgr;ll(-1) )，在田间条件下，在开顶室中从发芽到谷物成熟 8 小时，以评估响应 SO(2) 暴露导致 CO(2) 富集的修改。单独接触 SO(2) 会导致植物生长、生物量和产量减少，以及两种大豆品种的叶面淀粉和蛋白质含量下降。升高的 CO(2) 刺激了两个品种的植物生长、产量和增强的叶面淀粉含量、光合作用和 WUE。在暴露于升高的 CO(2)+SO(2) 组合的植物中，CO(2) 富集减轻了 SO(2) 的不利影响。这种影响被认为是由于提供了修复和解毒过程所需的额外碳源，以及通过降低气孔导度来减少 SO(2) 的吸收。PK 472 表现出对 SO(2) 比布拉格更高的敏感性。PK 472 在 CO(2)+SO(2) 处理下也表现出比布拉格更大的产量刺激。