The Phytotron, University of Oslo, Blindern, P.O.B. 1066, 3, Oslo, Norway.
Photosynth Res. 1985 Mar;6(1):87-96. doi: 10.1007/BF00029048.
Dry weight and Relative Growth Rate of Lemna gibba were significantly increased by CO2 enrichment up to 6000 μl CO2 l(-1). This high CO2 optimum for growth is probably due to the presence of nonfunctional stomata. The response to high CO2 was less or absent following four days growth in 2% O2. The Leaf Area Ratio decreased in response to CO2 enrichment as a result of an increase in dry weight per frond. Photosynthetic rate was increased by CO2 enrichment up to 1500 μl CO2 l(-1) during measurement, showing only small increases with further CO2 enrichment up to 5000 μl CO2 l(-1) at a photon flux density of 210 μmol m(-2) s(-1) and small decreases at 2000 μmol m(-1) s(-1). The actual rate of photosynthesis of those plants cultivated at high CO2 levels, however, was less than the air grown plants. The response of photosynthesis to O2 indicated that the enhancement of growth and photosynthesis by CO2 enrichment was a result of decreased photorespiration. Plants cultivated in low O2 produced abnormal morphological features and after a short time showed a reduction in growth.
高浓度二氧化碳（CO2）可使浮萍的干重和相对生长率显著增加，最高可增加至 6000μl CO2 l(-1)。这种高 CO2 最适生长可能是由于存在无功能的气孔。在 2%O2 中生长四天后，对高 CO2 的反应减弱或不存在。由于每片叶的干重增加，叶面积比随 CO2 富集而减少。在 210 μmol m(-2) s(-1)的光子通量密度下，CO2 富集可使光合速率增加至 1500 μl CO2 l(-1)，但进一步增加至 5000 μl CO2 l(-1)时，仅略有增加，而在 2000 μmol m(-1) s(-1)时略有下降。然而，在高 CO2 水平下培养的植物的实际光合作用速率小于在空气中生长的植物。光合作用对 O2 的响应表明，CO2 富集增强生长和光合作用是由于光呼吸减少的结果。在低 O2 中培养的植物产生异常的形态特征，并且在短时间后生长减少。
