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THE BLUE LIGHT GRADIENT IN UNILATERALLY IRRADIATED MAIZE COLEOPTILES: MEASUREMENT WITH A FIBER OPTIC PROBE
Author(s) -
Vogelmann T. C.,
Haupt W.
Publication year - 1985
Publication title -
photochemistry and photobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.818
H-Index - 131
eISSN - 1751-1097
pISSN - 0031-8655
DOI - 10.1111/j.1751-1097.1985.tb03528.x
Subject(s) - coleoptile , irradiation , optics , irradiance , materials science , fluence , physics , biology , botany , nuclear physics
— The blue light (450 nm) gradient was measured with a fiber optic microsensor in etiolated maize coleoptiles that were irradiated unilaterally. Patterns of transmitted and scattered light across the shoot were related to the morphology of the coleoptile and varied greatly between the coleoptile base, mid‐region and tip. In the coleoptile base, light was scattered equatorially around the coleoptile sheath so that there was more light on the shaded side of the sheath than in the shaded side of the primary leaves. In the hollow mid‐region there were strong reflecting boundaries at the air‐coleoptile interfaces, which resulted in step like transitions in the light gradient. In the coleoptile tip, there was a steep, near‐linear gradient of blue light, with the greatest amount of light on the irradiated side. There was no evidence that the coleoptile tip acts as a lens or that there are anomalies that result in more light on the shaded than irradiated side. Immediately beneath the irradiated surface, the space irradiance was about twice the fluence rate of the light beam. The magnitude of the light gradient was 4:1 between the irradiated and shaded side of the mid‐region and tip and 8:1 for the coleoptile base.