Effects of Shading and Fertilization on Photosynthesis of Alseodaphne Hainanensis Seedlings

The LI-6400 portable photosynthetic apparatus was used to determine the photosynthetic characteristics of 1-year-old Alseodaphne hainanensis under different shading conditions and fertilization treatments. The purpose was to investigate the physiological response of A. hainanensis to light environment changes and its adaptation mechanism. Results show that under full light conditions, strong light easily burn the leaves of seedlings, which is not conducive to photosynthesis. Under different light intensities, P_n rate of seedling leaves is characterized by 1 layer shading net shading treatment > 2 layers shading net shading treatment > full light treatment. P_{n max} appears in the shading treatment of 1 layer of shading net, which is 4.03 μmol/(m²·s). LSP, LCP and R_d all appear in the full light treatment, but decrease with the increase of shading. The difference of P_{n max} between 1 layer shading net shading treatment and the 1 layer shading net shading group + fertilization is not significant, but LSP, LCP, R_d and AQY are improved to some extent. In general, A. hainanensis seedlings are hi-light and semi-shade-resistant plants. One layer shading net shading is beneficial to improve the ability of A. hainanensis seedlings to capture light energy, improve photosynthesis and promote its growth. In the short term, the application of compound fertilizer increase the photosynthetic parameters to a certain extent, but its photosynthetic efficiency do not change significantly.