Chiang Camilo, Bånkestad Daniel, Hoch Günter
Department of Environmental Sciences-Botany, University of Basel, 4056 Basel, Switzerland.
Department of Research and Development, Heliospectra, 414 58 Gothenburg, Sweden.
Plants (Basel). 2020 Oct 5;9(10):1312. doi: 10.3390/plants9101312.
Recommendations for near-natural plant growth under indoor conditions have been described without considering environmental fluctuations, which might have important consequences for researchers and plant producers when comparing results from indoor facilities with natural ecosystems or production. Previous authors proposed that differences in temperature, light quantity, and the lack of their variation are sources of deviations between indoor and outdoor experiments. Here, we investigated the effect of fluctuating light, temperature, and humidity in an indoor environment on plant performance. Seven plant species from different functional plant types were grown outdoors during summer and spring. The same species were then grown in indoor growth chambers under different scenarios of climate complexity in terms of fluctuations of temperature, air humidity, and light: 1) fixed night and day conditions, 2) daily sinusoidal changes, and 3) variable conditions tracking the climate records from the field trials. In each scenario, the average of the environmental variables was the same as in the respective field trial. Productivity-, gas exchange-, and leaf pigment-traits were measured in all plants at the end of the experiments. The plant trait responses were highly dependent on species and treatment, but general trends were observed. The variable condition yielded lower biomass compared to the fixed and sinusoidal conditions, together with a higher specific leaf area and increased chlorophyll concentrations. A principal component analysis (PCA) across all plant traits in response to climatic conditions suggested that at least a sinusoidal fluctuation is recommended for a more natural-like plant performance in indoor growth facilities. However, prevailing significant differences for several traits between field- and indoor-grown plants even under variable climates indicate that additional factors other than those controllable in standard phytotrons (e.g., wind speed and direction, leaf and soil temperature) can still significantly bias plant performance in indoor facilities.
关于室内条件下近自然植物生长的建议已被描述，但未考虑环境波动，而在将室内设施的结果与自然生态系统或生产进行比较时，这可能会给研究人员和植物生产者带来重要影响。先前的作者提出，温度、光照量及其变化的缺乏是室内和室外实验之间偏差的来源。在此，我们研究了室内环境中光照、温度和湿度的波动对植物性能的影响。七种来自不同功能植物类型的植物在春夏季节种植于室外。然后，相同的物种在室内生长室中，在温度、空气湿度和光照波动方面具有不同气候复杂性的情况下生长：1）固定的昼夜条件，2）每日正弦变化，3）跟踪田间试验气候记录的可变条件。在每种情况下，环境变量的平均值与相应的田间试验相同。在实验结束时，测量了所有植物的生产力、气体交换和叶片色素特征。植物性状反应高度依赖于物种和处理，但观察到了一般趋势。与固定和正弦条件相比，可变条件下的生物量较低，同时比叶面积较高且叶绿素浓度增加。对所有植物性状响应气候条件的主成分分析（PCA）表明，为了在室内生长设施中实现更接近自然的植物性能，建议至少采用正弦波动。然而，即使在可变气候条件下，田间种植和室内种植的植物在几个性状上仍存在显著差异，这表明除了标准植物培养箱中可控的因素（如风速和风向、叶片和土壤温度）之外，其他因素仍可能显著影响室内设施中的植物性能。
