Response to Light Intensity of Cercidiphyllum japonicum Seedlings

Abstract:

In order to understand the effects of light intensity on growth of Cercidiphyllum japonicum seedlings, one-year-old seedlings were grown under 10% (L₁), 25% (L₂), 100% (L₃), 110% (L₄), and 125% (L₅) natural light intensity, and the adaptive ability in morphology and physiology of seedlings was studied. The results showed that the increase of plant height, biomass, leaf length, leaf width, and leaf area increased at first and then decreased with the increase of light intensity, and all of them reached the highest under L₂. The specific leaf area, leaf water content, and root shoot ratio continued to decrease, while the base diameter increased continuously. The peroxidase activity under L₁ and L₂ was significantly higher than that under L₄ and L₅, while the changes in malondialdehyde content was the opposite. With the increase of treatment time, the superoxide dismutase activity under L₂ increased at first and then decreased, which under L₁ continued to increase and was higher than that under L₃, L₄ and L₅. The contents of total chlorophyll, chlorophyll a and chlorophyll b decreased with the treatment time, and the stronger the light, the lower the content. Therefore, Cercidiphyllum japonicum seedlings could grow under both shade and strong light, and 25% natural light intensity was more suitable.