Clauw Helena, Van de Put Hans, Sghaier Abderahman, Kerkaert Trui, Vermeir Pieter, Steppe Kathy
Laboratory of Plant Ecology, Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Gent, Belgium.
Laboratory for Chemical Analysis, Department of Green Chemistry and Technology, Faculty of Bioscience Engineering, Ghent University, Gent, Belgium.
Front Plant Sci. 2025 Sep 12;16:1655271. doi: 10.3389/fpls.2025.1655271. eCollection 2025.
The closed environments of space farming and vertical farming systems allow for the implementation of innovative short light-dark cycles. These cycles have the potential to accelerate plant development and synchronize the short light period with off-peak electricity prices, thereby maximizing profitability. Previous work showed that growing spring wheat ( L.) under a 6h-6h light-dark cycle resulted in accelerated heading.
The present study investigates pre-anthesis development under this photoperiod, with a focus on the stem elongation phase as critical period for yield determination. In addition, the effect of transitioning to a 14h-10h light-dark cycle, mimicking spring conditions in the field, at heading was examined. This was assessed across sequential growth chamber experiments in combination with variations in light intensity and CO concentration. Wheat phenology and leaf traits, including SPAD values, nitrogen and nitrate content and photosynthetic rates, were monitored.
SPAD values, and thus leaf greenness, declined significantly in leaves developing around the start of stem elongation, leading to reduced photosynthetic rates. In these leaves, nitrate accumulation was detected. SPAD values increased following the shift to a 14h-10h light-dark cycle at heading, coinciding with higher photosynthetic rates.
These findings underscore the importance of aligning photoperiod regimes with plant developmental stages to optimize wheat production in controlled environments.
太空种植和垂直种植系统的封闭环境允许实施创新的短光照-黑暗周期。这些周期有可能加速植物发育，并使短光照期与非高峰电价同步，从而实现利润最大化。先前的研究表明，在6小时光照-6小时黑暗周期下种植春小麦（L.）会导致抽穗加速。
本研究调查了在此光周期下抽穗前的发育情况，重点关注茎伸长阶段作为产量决定的关键时期。此外，还研究了在抽穗期过渡到14小时光照-10小时黑暗周期（模拟田间春季条件）的影响。这是通过连续的生长室实验，并结合光照强度和二氧化碳浓度的变化来评估的。监测了小麦物候和叶片性状，包括SPAD值、氮和硝酸盐含量以及光合速率。
在茎伸长开始时发育的叶片中，SPAD值以及叶片绿色度显著下降，导致光合速率降低。在这些叶片中检测到硝酸盐积累。抽穗期转变为14小时光照-10小时黑暗周期后，SPAD值增加，同时光合速率更高。
这些发现强调了使光周期制度与植物发育阶段相匹配对于在可控环境中优化小麦生产的重要性。
