Abstract
Penetrating light into terrestrial plant leaf is refracted and absorbed by epidermis, palisade and spongy tissue, and then its qualities and quantities change. In this study microenvironment of light in broad bean leaf was determined by the spectrophotometer with a microprobe of fiber optics. The broad bean leaf was illuminated from the upper side with a halogen lamp simulating a scattered light and the microprobe was inserted into the leaf from the lower side. Blue (λ=480nm) and red (λ=680nm) light were well absorbed at palisade tissue and light intensity at the bottom of the tissue decreased to 21% of light on the upper surface. Green light (λ=550nm) penetrating to the lower side of the leaf was then absorbed by the spongy cells and only 5.8% of the light reached to the lower side. Scattered light determined at different angles was similarly absorbed by the leaf. A laser light (λ=680nm) simulating a direct sunlight was also used as a light source. The light was refracted by epidermis and palisade tissue and then got to be scattering light in the leaf.
