铁皮石斛在人工光型密闭式植物工厂的适宜光照强度

Suitable Lighting Intensity of Dendrobium officinale in vitro in Closed Plant Factory under Artificial Lighting

人工光型密闭式植物工厂适于高附加值植物尤其是珍贵药用植物的大规模/低成本化生产,其环境调控对珍贵药用植物的产量和质量有重要影响。笔者研究探索在控制温度、湿度、CO2浓度和光周期的条件下,光照强度对铁皮石斛(Dendrobium officinale)组培苗生长发育的影响,以期找到铁皮石斛组培阶段在人工光可控环境下的适宜光照环境。鲜重约300mg的铁皮石斛单腋芽作为外植体在温度24±1℃、湿度65±5%、光周期12h/d、及光期CO2浓度800±50μmol/mol的环境条件下,设置光照强度为37、68、92、120μmol/(m2·s)的4组试验区,并使用容积为380mL的方型聚碳酸酯组培容器在人工光型密闭式植物工厂中培育92d。组培容器的顶部留2个直径为10mm的圆孔覆盖高分子透气膜用来与容器外进行气体交换。铁皮石斛组培苗的生长发育和生理活性在光照强度为68μmol/(m2·s)时最佳,超过92μmol/(m2·s)时呈现明显的光抑制;多糖含量随着光照强度的增强而增加,超过92μmol/(m2·s)时呈下降趋势,但是68和92μmol/(m2·s)光照强度试验区的多糖含量没有显著性差异。因此,铁皮石斛组培苗在人工光型密闭式植物工厂内培育的适宜光照强度为60￣70μmol/(m2·s)。

Closed plant factory under artificial lighting is suitable for producing value-added plant especially trueborn medicinal herbs in low cost and large scale, and the controlled environments are important for their yield and quality. The suitable lighting intensity with controlled temperature, humidity, CO2 concentration and photoperiod were studied for Dendrobium officinale in vitro in a closed plant factory using fluorescent lamps as the lighting source. Single D. officinale explants each with 300 mg fresh mass were planted in polycarbonate culture vessels with volume of 380 mL and filtered by twoφ10 mm gaspermeable filters on the vessel tops. The four treatments with lighting intensities of 37, 68, 92, 120 μmol/（m^2·s） were controlled at air temperature of 24±1℃, relative humidity of 65±5%, photoperiod of 12 h/d, and CO2 concentration of 800 ±50 μmol/mol for 92 days for the D. officinale in vitro. The growth and physiological characters of D. officinale in vitro on day 92 were better in the treatment with lighting intensity of 68 μmol/（m^2·s） and were shown in photoinhibition over lighting intensity of 92μmol/（m^2·s）. The polysaccharide contents increased with increasing lighting intensity less than 92 μmol/（m^2·s）, but no significant differences were found between treatments with lighting intensities of 68 and 92 μmol/（m^2·s）. Therefore, the suitable lighting intensity for D. officinale in vitro is 60-70μmol/（m^2·s） in the closed plant factory under artificial lighting.