Dannehl Dennis, Kläring Hans-Peter, Schmidt Uwe
Faculty of Life Sciences, Albrecht Daniel Thaer-Institute of Agricultural and Horticultural Sciences, Division Biosystems Engineering, Humboldt-Universität zu Berlin, Albrecht-Thaer-Weg 3, 14195 Berlin, Germany.
Leibniz Institute of Vegetable and Ornamental Crops (IGZ) e.V., Theodor-Echtermeyer-Weg 1, 14979 Großbeeren, Germany.
Plants (Basel). 2021 Dec 18;10(12):2808. doi: 10.3390/plants10122808.
Concepts of semi-closed greenhouses can be used to save energy, whereas their technical equipment often causes a decrease in the light received by the plants. Nevertheless, higher yields are achieved, which are presumably triggered by a higher CO concentration in the greenhouse and associated higher photosynthesis because of the technical cooling and the longer period of closed ventilation. Therefore, we examined the effects of photosynthetic photon flux density (PPFD) and CO concentration on plant photosynthesis and transpiration in tomato using a multiple cuvette gas exchange system. In a growth chamber experiment, we demonstrated that a light-mediated reduction in photosynthesis can be compensated or even overcompensated for by rising CO concentration. Increasing the CO concentration from 400 to 1000 µmol mol within the PPFD range from 303 to 653 µmol m s resulted in an increase in net photosynthesis of 51%, a decrease in transpiration of 5 to 8%, and an increase in photosynthetic water use efficiency of 60%. Estimations showed that light reductions of 10% can be compensated for via increasing the CO concentration by about 100 µmol mol and overcompensated for by about 40% if CO concentration is kept at 1000 instead of 400 µmol mol.
半封闭温室的概念可用于节能，但其技术设备往往会导致植物接收到的光照减少。尽管如此，产量却有所提高，这可能是由于温室中较高的二氧化碳浓度以及由于技术冷却和较长时间的封闭通风而带来的较高光合作用所致。因此，我们使用多比色皿气体交换系统研究了光合光子通量密度（PPFD）和二氧化碳浓度对番茄植株光合作用和蒸腾作用的影响。在生长室实验中，我们证明了光合作用中由光照介导的降低可以通过提高二氧化碳浓度得到补偿甚至过度补偿。在PPFD范围为303至653微摩尔每平方米每秒的情况下，将二氧化碳浓度从400微摩尔每摩尔增加到1000微摩尔每摩尔，导致净光合作用增加51%，蒸腾作用减少5%至8%，光合水分利用效率提高60%。估算表明，如果将二氧化碳浓度保持在1000微摩尔每摩尔而不是400微摩尔每摩尔，光照减少10%可以通过将二氧化碳浓度提高约100微摩尔每摩尔得到补偿，并可过度补偿约40%。
