Photosynthesis-Light Response Curve Derived from Light Absorbed in a Leaf : I. Model of Light Absorption in Each Mesophyll Layer of a Leaf

Since a leaf has a certain thickness, each mesophyll layer in it absorbs different light energy. In this paper, by using parameters related with the light transmission and reflection of a leaf, the equation describing the absorption of light in each layer of a leaf was proposed. Spectral distribution of tobacco, soybean, corn and rice plant leaves with different chlorophyll content were measured by a spectra-photometer equipped with spherical ball and opal glass. Attenuation coefficients of visible light to chlorophyll content of a leaf on dicotyledonous plants (tobacco and soybean) were larger than that of monocotyledonous plants (corn and rice). But there was no difference of reflection coefficient in either plant type. On a leaf with high chlorophyll content, light absorption of lower mesophyll layer of a leaf was smaller than that on a leaf with low content