Yamori Namiko, Levine Christopher P, Mattson Neil S, Yamori Wataru
Institute for Sustainable Agro-Ecosystem Services, The University of Tokyo, Nishitokyo, Japan.
School of Integrative Plant Science, Cornell University, Ithaca, NY, USA.
Plant Mol Biol. 2022 Nov;110(4-5):385-395. doi: 10.1007/s11103-022-01249-w. Epub 2022 Feb 15.
The present study clearly showed that the optimum root zone temperature of photosynthesis and plant growth was affected by air temperature, and that optimization of root zone temperature depending on an air growth temperature by cooling systems could lead to improvement of plant production. Temperature is one of the critical factors affecting plant growth and yield production. Both air and root zone temperatures can strongly affect growth and development of plants. However, studies on the effects of root zone temperature on plant growth parameters along with air temperature are still limited. In the present study, the effects of air and root zone temperature on plant growth, physiological parameters and photosynthetic characteristics of lettuce plants were investigated to optimize the air and root zone temperature to achieve the best growth conditions for lettuce plants. Two air temperature treatments (30/25 and 25/20 °C at day/night temperature) and five root zone temperature treatments (15, 20, 25, 30 and 35 °C) were applied in this study. The present study showed that the maximum plant growth of lettuce plants was higher in air temperatures at 30/25 °C than in 25/20 °C. When the plants were grown at an air temperature of 30/25 °C, the optimum root zone temperature appeared to be 30 °C. However, when the plants were grown at an air temperature of 25/20 °C, the optimum root temperature decreased and appeared to be 25 °C. Furthermore, plants grown under air temperature of 30/25 °C showed greater CO assimilation rate, stomatal conductance, electron transport rate (ETR) at high light, and lower non-photochemical quenching (NPQ) at high light than those of 25/20 °C. These results suggest that it is necessary to control and adjust the root zone temperature based on the air temperature.
本研究清楚地表明，光合作用和植物生长的最佳根区温度受气温影响，通过冷却系统根据气温优化根区温度可提高植物产量。温度是影响植物生长和产量的关键因素之一。气温和根区温度都会强烈影响植物的生长和发育。然而，关于根区温度与气温对植物生长参数影响的研究仍然有限。在本研究中，研究了气温和根区温度对生菜植株生长、生理参数和光合特性的影响，以优化气温和根区温度，为生菜植株实现最佳生长条件。本研究采用了两种气温处理（日/夜温度为30/25和25/20°C）和五种根区温度处理（15、20、25、30和35°C）。本研究表明，生菜植株在30/25°C气温下的最大生长量高于25/20°C。当植株在30/25°C气温下生长时，最佳根区温度似乎为30°C。然而，当植株在25/20°C气温下生长时，最佳根温降低，似乎为25°C。此外，与25/20°C下生长的植株相比，在30/25°C气温下生长的植株在高光下表现出更高的CO同化率、气孔导度、电子传递速率（ETR）和更低的高光下非光化学猝灭（NPQ）。这些结果表明，有必要根据气温控制和调节根区温度。
