Abstract: The morphological plasticity of Pinus koraiensis, Picea koraiensis and Larix olgensis to shade tolerance, and the level and distribution of their endogenetic hormones were studied in forests with different canopy density. The morphological plasticity of Pinus koraiensis to shade-tolerance promoted the growth of apical branches and increased the specific leaf area (SLA); while that of Picea koraiensis benefited the number of lateral branches and SLA. Under low light intensity, the increasing growth of apical branches and the increasing SLA of Pinus korainensis were positively correlated to the content of endogenetic hormone Zin corresponding positions. The content of endogenetic hormone Z Rin top leaves of Picea koraiensis was positively correlated with the SLA, and the number of lateral branches was negatively correlated with the content of ABAin bifurcated positions. Among the three conifers, Pinus korainensis was the most suitable to low light intensity.

Key words: Shade-tolerance, Morphological plasticity, Hormone, shading, yellowing, tea plant, Huangjinya