Abstract:In order to investigate the effects of different intensity of LED yellow light on the biological characteristics and quality of Paris polyphylla var.yunnanensis, and to provide theoretical basis for the application of LED light source in the production of Paris polyphylla var.yunnanensis, 3-year-old seedlings of Paris polyphylla var. yunnanensis were used as experimental materials and 4 light intensity gradients of 25, 50, 75, 100 μmol/(m2·s) were set for irradiating the yellow light with a wavelength of 590 nm±5 nm. The fresh weight, photosynthetic fluorescence characteristics of leaves and saponins content of rhizome were studied. The results showed that the net photosynthetic rate, fluorescence index, stomata conductance and transpiration rate were the highest in leaves with 75 μmol/(m2·s) treatment and the fluorescence index was the lowest with 25 μmol/(m2·s) treatment. The saponins content of rhizome was the highest with 100 μmol/(m2·s) treatment and lowest with 25 μmol/(m2·s) treatment. Comprehensive analysis of photosynthetic characteristics of leaves and saponins content of rhizome showed that, 75 μmol/(m2·s) intensity of LED yellow light was favorable to promote the photosynthesis and 100 μmol/(m2·s) intensity could increase the saponins content in rhizome of Paris polyphylla var.yunnanensis. Consequently, the yellow light intensity should be controlled appropriately at 75-100 μmol/(m2·s) on the cultivation of Paris polyphylla var. yunnannensis.
